The user uploaded an image and asks to count how many food chains (食物链) there are. This is likely a biology question showing a food web (食物网) image. Let me read the image file first.

This is a classic Chinese biology textbook food web image (某陆地生态系统的食物网 - "Food web of a terrestrial ecosystem"). This is a famous figure from 人教版七年级上册生物学 (People's Education Press 7th grade biology textbook).

The classic version of this food web contains:

In the classic textbook version, there are 9 food chains:

Wait, but this image looks a bit different - it seems to have more animals. Let me look carefully at the image:

From the image I can see:

Hmm, this appears to be a modified/extended version of the classic food web. Let me look at the arrows more carefully.

The arrows are color-coded:

Let me trace the arrows:

Blue arrows from grass (草):

Hmm wait, let me re-examine. The bottom row: 兔 (rabbit), then a marmot/groundhog-like animal, then a small dark rodent (mouse?), then a small bird, then an insect (moth/grasshopper).

Actually, looking at this more carefully, this seems to be an extended version with possibly:

This is tricky because I need to trace all the arrows. Let me zoom into the image to trace the arrows more carefully. I should use the IPython tool to crop and zoom into different parts of the image.

Let me do that to carefully identify all the arrows.

Let me view the cropped images.

Now I can see the bottom row clearly. From grass, blue arrows go to:

So 5 primary consumers: 兔, 旱獭(groundhog/marmot), 鼠(mouse), 鸟(bird), 食草昆虫(insect)

Wait, let me look at the image again. In the bottom crop I see:

5 blue arrows from grass pointing to: rabbit, marmot, mouse, bird, insect.

Now let me view the middle section.

Now I can see the middle section. Animals in this food web:

Now let me trace the arrows:

From the middle crop:

Actually the green arrows: 食草昆虫→青蛙, 食草昆虫→蜘蛛, 蜘蛛→青蛙, 食草昆虫→小鸟?

Blue arrows in middle: pointing to 蛇 from various sources (蛇 eats 鼠, 青蛙, 兔?). There are blue arrows pointing at the snake. And blue arrows pointing toward the fox from below (狐 eats 兔, 鼠, 旱獭).

Let me zoom into specific areas to trace each arrow carefully. This is getting complex. Let me look at the top crop first.

Now I can see the top. The eagle (鹰) has many orange/brown arrows pointing to it. The magpie (喜鹊) is at top right with arrows pointing from it to the eagle (喜鹊→鹰, meaning eagle eats magpie).

Let me count the orange arrows pointing to the eagle:

Let me identify all orange (鹰-related) arrows:

Actually in the top crop, I see an orange arrowhead around (790, 990) in the 2x scaled coords... Let me map carefully.

Actually, let me be systematic. Let me zoom into regions and trace each arrow by color:

Let me zoom into specific regions at high magnification to trace arrows.

Region 1: Around the eagle (to count incoming arrows to eagle) Region 2: Around the fox (incoming arrows) Region 3: Around the snake (incoming) Region 4: Around the magpie (incoming) Region 5: Around frog and spider (incoming) Region 6: Around the small bird (incoming)

Let me crop tighter regions at 3x zoom.

In this crop (x=900-1750, y=250-700 of original), I can see orange arrows pointing to the eagle:

So in this crop I count 5 orange arrowheads. Plus from the top.png earlier, there were more arrows on the left side of the eagle (from fox area and below-left).

Let me look at the full eagle surroundings. In top.png I saw:

Let me crop a wider region around the eagle including left side.

In this crop (original x=450-1300, y=400-750), I see orange arrows pointing to the eagle:

Plus the 3 arrows seen in the previous crop on the right side (from magpie direction).

Wait, I need to be careful. In eagle.png (x=900-1750, y=250-700) I saw 5 arrowheads:

In eagle2.png (x=450-1300, y=400-750) I see 5 arrowheads:

The two vertical ones appear in both crops. So total unique orange arrowheads pointing to eagle:

Hmm, that would be 8 prey for the eagle? That seems like a lot. Let me check the original full image again. In the first full view, I saw orange arrows to the eagle from: magpie (top right), and several from below.

Actually wait. Let me re-examine. In the very first full image view, near the eagle I saw orange arrowheads at approximately:

That's 8 arrows into the eagle. Hmm, but some of these arrows might originate from: 兔, 鼠, 旱獭, 蛇, 青蛙?, 鸟, 喜鹊...

Actually let me trace each arrow back to its source. This requires following the curves. Let me use color segmentation to extract orange arrows and track them.

Actually, a better approach: this is a known textbook image. Let me search for it. The caption is "图3-4 某陆地生态系统的食物网" - This looks like it's from 人教版七年级上册《生物学》but the classic one has 9 food chains with: 草、兔、鼠、狐、蛇、鹰、青蛙、食草昆虫、蜘蛛、鸟.

But this version has MORE animals: 兔、旱獭(marmot)、鼠、鸟、昆虫、狐、蛇、青蛙、蜘蛛、喜鹊、鹰. This might be the 2024新版人教版 (new edition) textbook. In the new 2024 edition of 人教版七年级上册, the food web figure was updated.

Let me search the web for this specific figure to verify the food chain count. But first, let me carefully trace arrows myself since the image is right here.

Let me do color-based arrow extraction to be precise.

The color thresholds didn't capture well. The arrows are probably muted colors (brown-orange, steel blue). Let me sample actual pixel colors from arrow locations. Let me look at the image more interactively - sample colors at known arrow positions.

Let me instead display the image with a coordinate grid overlay so I can pinpoint arrow locations manually.

Now with the grid I can see the layout better:

Animals:

Arrows (orange = to eagle, blue = others, green = insect-related):

From grass (blue arrows at bottom):

Now arrows pointing to the EAGLE (orange):

Hmm, so potentially 8 arrows into the eagle. Let me trace each back:

Hmm wait. Actually in the classic textbook food web, the eagle eats: 兔、鼠、蛇、鸟(喜鹊). In this extended version maybe also 旱獭、青蛙、蜘蛛?

Let me trace each orange curve carefully. I'll crop regions along each curve. Better: let me segment the orange/brown color. The arrows are brownish-orange. Let me sample pixel colors near an arrowhead, e.g., at (930, 320).

My point sampling isn't precise. Let me take a different approach — trace arrows visually with targeted high-zoom crops along each path. Let me start with the orange arrows into the eagle. I'll crop the region around each arrowhead and follow the line.

Actually, a cleaner approach: since this is a known textbook figure ("图3-4 某陆地生态系统的食物网"), let me search the web to find the original figure and the standard answer for the number of food chains. This appears to be from the 2024 new edition 人教版 biology textbook (七年级上册). Let me search.

The search didn't find this exact figure's standard answer. This appears to be a newer textbook edition (2024 人教版七年级上册 might have updated figures). The classic version has 9 food chains, but this image has extra animals (旱獭, 喜鹊, and the small bird).

I need to carefully trace the arrows myself. Let me do it systematically with high-zoom crops. Let me establish the animal positions first:

Now the arrows. Let me trace by color groups:

GROUP A - Orange arrows pointing to eagle (鹰): Arrowheads seen at approximately:

That's potentially 8 prey items for eagle: 兔, 旱獭, 鼠, 蛇, 青蛙, 小鸟, 蜘蛛?, 喜鹊. Hmm.

Wait, but maybe some of those arrows I counted are actually the same curve seen at different points, or some arrowheads near the eagle's right side at (920-930, 320-375) region. In the eagle.png crop (900-1750, 250-700), I saw 3 arrowheads clustered at top-left of that crop (which is around original (1180, 315), (1175, 350), (1165, 378))...

Hold on, let me recompute. eagle.png crop was x: 900-1750, y: 250-700, scaled 3x. In that crop image, arrowheads appeared at crop coords approximately:

So arrowheads near eagle at: (1173,320), (1167,350), (1157,373), (1157,527), (1033,587), (923,597), and from eagle2.png crop (x:450-1300, y:400-750, 3x): arrowheads at crop coords:

So consolidated unique orange arrowheads pointing at eagle:

8 arrows into the eagle. Now trace each back to source:

Arrow 6 (1173,320): The curve goes to the right, rising up toward the magpie at (1700,380). In eagle.png I saw the curve going right and slightly up. So 喜鹊→鹰.

Arrow 7 (1167,350): curve goes right-down. In eagle.png the second curve also went right. In the grid image, I see a curve from the eagle's right side going down-right toward the spider area (1740,770). Hmm, could be 蜘蛛→鹰? Or it goes to 青蛙?

Arrow 8 (1157,373): this curve goes down steeply (in eagle.png it went down-right crossing the blue line). Could go to frog or small bird.

Arrow 5 (1160,527): vertical-ish, in eagle.png and eagle2.png, it goes down. Looking at the grid image, there's a brown/orange curve from the eagle going down at x~1200, passing (1200,800) area down to... the frog (1390,780)? Actually in the grid image I see a vertical brown line at x~1200 from y~520 down to y~800+ where it might connect to the frog or continue to the small bird (1440,1130)?

Hmm, wait. Let me look at the grid image again. Brown/orange curves:

This is getting complicated. Let me trace each colored line systematically using image processing — extract orange lines and follow them. Let me build a proper color mask for the brown-orange arrows.

The arrow colors: brownish orange. From the earlier sample 'eagle_arrow_2' at (1040,585): mean RGB (153,126,108) with min (121,98,79). So the line color is roughly RGB(120-160, 95-130, 75-115) — a muted brown.

Blue arrows: sample 'blue_snake' at (1130,740): mean (152,169,184), min (102,124,138). So blue-gray: RGB(100-160, 120-175, 135-190), B > R.

Let me create masks in HSV space and visualize them properly.

The brown mask has 223k pixels — way too many, it's catching the animals (fox, eagle feathers, etc.). Let me view the mask to see how clean it is.

The mask is noisy but I can actually see the arrow structure. The brown/orange lines (pointing to eagle):

Hmm wait, actually looking more carefully at the mask, that curve's left end curves down toward the fox's head area. In the original image (grid version), the curve with arrowhead at (700,500) — following it left it goes down toward... (490, 600) near the fox's mouth? That seems odd.

Hold on. Let me reconsider. In many versions of this food web, 鹰's prey includes 兔, 鼠, 蛇, and sometimes 鸟. The fox is usually NOT preyed by the eagle.

Let me look at the curve again in the mask: the arrow with head at (700,495) traces back left-down to about (490,605). And there's the fox right there. But hmm, maybe the curve actually starts from the rabbit (320,1040)? No...

Actually wait. Let me look at the brown curves in the mask more carefully:

Brown curve 1: head at (700,495), traces left-down to (490,605). Brown curve 2: head at (883,550), traces left-down... it's the long curve going to the bottom-left, down to (610,1030) area near the marmot (620,1120). Yes! I can see in the mask a long brown curve from (883,550) going down-left, passing (600,700), (590,900), ending around (610,1030). That's near the 旱獭 (marmot at (620,1120)). So 旱獭→鹰. Brown curve 3: head at (927,593), traces down-left to... the mouse (1030,1130)? In the mask I see a brown curve from (927,593) going down to (1000,1050) and ending near (1030,1090) — that's the mouse. So 鼠→鹰. Brown curve 4: head at (1037,587), vertical line going straight down to the snake (1000,780). So 蛇→鹰. Brown curve 5: head at (1160,527), traces down-right... in the mask I see a brown curve from (1160,527) going down at x~1200 to (1200,800) and continuing? It seems to go down to the frog (1390,780) or to the small bird? Hmm, in the mask image there's a brown curve going from (1160,527) down along x~1200-1250, then curving right toward the frog at (1390,780)? Actually I see the curve passes near the frog's left side...

Hmm, wait. Actually looking at the mask image again, near the frog there are green arrowheads pointing TO the frog from the right. The brown curve coming down from the eagle at x~1200 reaches down to about y~800 at x~1200-1250 and seems to end near... the frog is at (1390,780). Close but not exactly.

Hmm, but actually, maybe the brown curve 5 continues further down to the small bird at (1440,1130)? In the mask, I can see a brown curve that dips down to (1020,1060) — wait no.

Let me look at the brown curves 6,7,8 (the ones with heads at (1173,320),(1167,350),(1157,373)):

Hmm wait, curves 5 and 8 might be the same curve. Let me re-examine: curve 5 head at (1160,527) and curve 8 head at (1157,373) are different arrowheads (both visible in eagle.png and eagle2.png as separate heads).

In eagle2.png (crop 450-1300, 400-750), I saw 5 arrowheads: (713,493), (883,552), (927,593), (1037,587), (1160,527). And there's a 6th one partially? No, 5 heads.

In eagle.png (crop 900-1750, 250-700), I saw heads at (1173,320), (1167,350), (1157,373), (1157,527)=(1160,527) same as before, (1033,587)=(1037,587) same, (923,597)=(927,593) same.

So 8 distinct brown arrowheads into the eagle total: (713,493), (883,552), (927,593), (1037,587), (1160,527), (1173,320), (1167,350), (1157,373).

Now trace sources:

Actually wait — maybe I have this backwards. Maybe the curve with head at (713,493) actually comes from the RABBIT, going up-left first. Let me trace it in the mask: from head (713,493), the curve goes left-down to (490,600), and at (490,600) it ends near... hmm, in the original grid image, at (490,600) I see the curve endpoint. The fox's nose is at about (480,610)? The fox image spans roughly x=150-480, y=560-760. So the curve starts right at the fox's nose/head. That would mean 狐→鹰?

Hmm, that's biologically odd for a textbook but let me verify visually. Actually, hold on — maybe that arrow goes FROM the eagle TO the fox? No wait, the arrowhead is at the eagle end (713,493 is near the eagle's tail at (1000,500)). Hmm, (713,493) is 300px left of the eagle. The arrowhead points up-right toward the eagle. So prey is at the left end (the fox). So 狐→鹰??

Wait, actually no! Let me look again. Maybe the arrowhead at (713,493) is pointing LEFT-DOWN, away from the eagle, i.e., the arrow goes from eagle to... no, that makes no sense ecologically.

Hmm, wait. Actually maybe I misidentified the direction. Let me zoom in on the arrowhead at (713,493).

Also the blue arrows: let me identify them: Blue arrowheads visible in mask:

And green arrows: 昆虫→蜘蛛, 昆虫→青蛙, 蜘蛛→青蛙, 昆虫→小鸟, 蜘蛛→小鸟?

This is a complex web. Let me carefully trace ALL arrows with zoomed crops. I'll do it region by region. Let me first verify the arrowhead direction at (713,493) — crop around it.

This crop is x:250-780, y:550-1080, scaled 3x. I can see:

Wait, looking at the crop again: there are two blue curves crossing near the bottom center, both ending at the bottom edge around crop x=1000-1100 (original x~583-617). And there's another blue curve (straighter, darker) going from arrowhead 3 down-right to crop right edge at (1590,1130) → original (780, 927) — continuing further right, probably to the mouse (1030,1130).

Also there's a 4th blue line: from arrowhead at crop (690,470) → original (480,707)? Actually I see 4 blue arrowheads: crop positions (230,575), (520,570), (620,530), (690,470). The 4th at (690,470) → original (480,707). Its curve is the straight dark one going down-right across the whole crop to the right edge at crop (1590,790) → original (780,813), continuing right — probably to the mouse or the small bird.

Wait, that brown curve's lower end is at original ~(495,605) and it doesn't touch any animal? That's strange. Unless... the curve continues but is occluded/light. Hmm. Actually, hold on. Look at the brown curve at the bottom of the crop: there's a brown curve forming a big arc from crop (230,1050) → original (327,900) down around to crop (1000,1500) → original (583,1050) and continuing up-right as the brown line going to crop top-right (1590,390) → that's the long brown curve to the eagle (head at 883,552).

So the brown arc: starts near original (327,900)?? Hmm wait, at crop (230,1050) the brown curve goes down out of the crop... to the rabbit (320,1040)! Yes — the rabbit is at bottom-left, and the brown curve passes down to it. So this brown curve goes: 兔→...→鹰? It starts at the rabbit (320,1040), curves up around (330,900), then sweeps right and down to (583,1050), then up-right as a long curve to the eagle with arrowhead at (883,552)??

Hmm wait, that doesn't look right either. Let me re-examine. In the crop:

Hmm, wait, but actually curve B at its left end (225,1040) — does it continue down out of the crop to the rabbit? The rabbit's head top is at crop (200,1130). The curve at crop (225,1040) is just above the rabbit. It likely continues down to the rabbit (320,1040).

Actually hold on, in the original grid image, I recall seeing a brown curve from the rabbit area going UP to the eagle — yes: "兔→鹰". The brown curve B is: 兔→鹰, sweeping right then up to the eagle (arrowhead at (883,552)).

And the other long brown curve to the eagle with head at (927,593): in the grid image it comes from the mouse (1030,1130)? Or marmot? Let me check: in the mask image, brown curve with head (927,593) went down to (1000,1050) and ended near the mouse. And the brown curve with head (883,552) went down-left to the marmot (620,1120)?

Hmm wait, but now curve B in this crop seems to go to the RABBIT and connect to arrowhead (883,552). Let me re-check by following curve B right: at crop right edge (1590,400) → original (780,683). Continuing in the original image from (780,683) going up-right... to (883,552)? That's plausible, it's a straight-ish line.

Then what goes to arrowhead (927,593)? And what about the marmot and mouse connections to the eagle?

Let me look at z2_center.png which covers (550-1150, 850-1250).

This crop is x:550-1150, y:850-1250, scaled 3x. I see:

Curves in this crop:

Wait, but hold on. Look at the left of the crop: there's a brown line entering from top-left corner (crop (100,0)) going down, curving at bottom (crop (190,580)) and going back up as a BLUE line? Hmm, actually I see two parallel curves on the left: a brown one and a blue one close together, both making U-turns near (613,1043).

Actually looking carefully: the leftmost curve at crop x~90-190 is BROWN (it has the orange tint), making a U at crop (190,580). And immediately right of it, a BLUE curve making a U at nearly the same spot, crop (200,585). Hmm, hard to tell. Let me zoom into that specific U-turn region.

So far:

Wait, I need to recheck the two left U-dips. In z2 crop, at the left there appear to be TWO U-shaped dips close together near original (610,1043): one brown, one blue. The brown one = 旱獭→鹰; the blue one = 旱獭→狐.

And in z1 crop, the brown curve B (from rabbit) — its U bottom was at crop (1000,1500) → original (583,1050). Hmm, that's the same location as the U-dips in z2! (583,1050) vs (610,1043). So actually curve B in z1 is the same as the left U-dip in z2. But wait — in z1 I thought curve B went left to the rabbit. Let me re-examine z1: curve B entered from crop left-bottom at (225,1040) → original (325,897), curved down-right. Hmm, but does it connect to the rabbit?

Actually wait. In z1, the brown curve B: enters at crop (225,1040) [original (325,897)], curves down and right to crop (1000,1500) [original (583,1050)], then up-right exiting at crop (1590,400) [original (780,683)]. So the curve passes original (325,897) — does it continue down to the rabbit at (320,1040)? At crop (225,1040), the curve is going down-left. The rabbit's ears top at crop (200,1130). Hmm, there might be a gap. OR the curve B left end actually connects DOWN to the rabbit.

Hmm, actually wait. I recall in z1, there was also the blue curve (兔→狐) that went from the fox's blue head (327,742) down-left to the rabbit. And separately brown curve B passing near the rabbit. Let me look at the region between rabbit (320,1040) and the U-dip (583,1050) carefully — does the brown curve touch the rabbit?

Let me crop (280-680, 850-1150).

This crop (280-700, 850-1160) shows:

Hmm interesting. At crop top-left, I see a BLUE curve and a BROWN curve coming down and meeting at crop ~(150,220) → original (317, 905), right above the rabbit's ears (rabbit ears top at crop ~(200,320) → original (330,930)).

Wait, actually they don't touch the rabbit directly but they're very close above its head. The blue one: 兔→狐 (from fox's blue arrow). The brown one: 兔→鹰!

So the brown curve B from z1 = 兔→鹰: it starts at the rabbit's head (317,905), sweeps right-down to the U at (583,1050)...

wait no. Hmm. In this z3 crop, the brown curve at top-left ends at (317,905). In z1, the brown curve B entered the crop at (225,1040)→original(325,897) — same point! Yes, consistent: the brown curve's left end is at the rabbit (325,897)≈(317,905). So 兔→鹰: from rabbit, curving down-right to U at (583,1050), then up-right to the eagle with arrowhead at (883,552).

Wait, but hold on — that means the brown curve dips down to (583,1050) which is right above the MARMOT (550-717, 1083-1183). And then goes up. And separately in z2, I saw another U-dip at (613,1043) which I attributed to 旱獭→鹰. Are these the same U or different?

In z1 crop (250-780,550-1080): brown curve B's U bottom at crop (1000,1500) → original (583,1050). In z2 crop (550-1150,850-1250): the left U-dip at crop (190,580) → original (613,1043).

(583,1050) vs (613,1043) — close, could be the same curve measured differently, or two adjacent curves. In z2 I thought I saw TWO U-dips side by side (one brown at ~(190,580)crop, one blue at ~(200,585)crop). And in z3 crop (280-700,850-1160), at the top-right I see the curves again: a brown curve and blue curve making U-turns at crop (1350,790) → original (617,1047).

Hmm, so at original ~(583-617, 1043-1050), there are U-turns of: (a) the brown 兔→鹰 curve, (b) a blue curve (旱獭→狐).

And is there a separate brown U-dip for 旱獭→鹰? In z2, at the left I saw the brown curve coming from top-left corner down to the U. In z1, the brown curve B went UP-RIGHT after the U (toward eagle head (883,552)). So the brown curve is: rabbit → (317,905) → sweep right → U at (583,1050) → up-right to eagle (883,552). That's ONE curve: 兔→鹰.

Then what about the marmot? Does any brown curve touch the marmot (550-717, 1083-1183)? The U bottom at (583,1050) is just ABOVE the marmot's back (marmot top at y~1083). It's ambiguous whether the curve dips to the marmot or just passes near. But the curve clearly STARTS at the rabbit (317,905). So this curve is 兔→鹰 only.

Hmm wait, but actually, maybe I have it wrong. Maybe the curve doesn't start at the rabbit. Let me look at z3 again: at crop top-left, the blue and brown curves come down and END at crop (150,215). They're cut off at the top of the crop? No wait, they come from the TOP of the crop (from the fox area) and end at crop (150,215) → original (317,905).

Hold on, actually looking again at z3: the blue curve comes from top (from fox) down to (317,905) — wait, no. The blue curve with arrowhead at the FOX means fox eats rabbit, arrow points rabbit→fox. The blue curve I see in z3 at top-left: it ends at (317,905) near the rabbit — this is the rabbit-end of the 兔→狐 curve (the arrowhead is at the fox end).

Similarly the brown curve ending at (317,905): this is the rabbit-end of 兔→鹰 (arrowhead at eagle end (883,552)).

So both blue and brown curves terminate right above the rabbit's head.

So:

Now the blue U-dip at (617,1047) near the marmot: in z1, the blue curve from fox head (423,740) went down-right and made a U at (613,1043)... wait no. Let me re-examine. In z1, blue arrowheads at crop (520,570)→original(423,740) and (620,530)→original(457,727). Two blue curves going down-right from the fox. One of them U-dips at (613,1043) near marmot and goes back up? No wait...

Hmm, actually in z3 crop, at the top-right I see: a BROWN curve and a BLUE curve coming down together, making U-turns at crop (1350,790) → original (617,1047), then the brown goes up-right (to eagle) and the blue goes up-right too (to... where?).

Ugh, this is getting confusing. Let me carefully list what I see in z3 top-right corner (original ~600-700, 850-950):

So near the marmot's back (617,1047), a brown curve and a blue curve both make U-turns. Neither actually touches the marmot (there's a visible gap to the marmot's back at y~1083? crop shows marmot top at crop y~920 → original y~1080, and U bottom at crop y~790 → original y~1047 — gap of ~33px).

Hmm OK here's the thing: these U-turns are just the curves' paths — the brown one goes rabbit→eagle (dipping down), and the blue one goes marmot→fox? But wait, if the blue curve U-turns near the marmot WITHOUT touching it, then it's not connected to the marmot.

Let me reconsider: maybe the blue curve's U-turn at (617,1047) IS the marmot connection point — the curve just grazes near the animal. In textbook diagrams, arrows often start near (not exactly touching) the animal.

So which animals do the two fox-bound blue curves come from? Fox blue heads: (327,742), (423,740), (457,727), (480,707) — 4 heads?? In z1 I saw 4 blue arrowheads near the fox: crop (230,575), (520,570), (620,530), (690,470) → original (327,742), (423,740), (457,727), (480,707).

Wait, in the mask image earlier, I saw blue arrowheads near fox at: (320,745), (430,725), (470,715) — 3 heads. In z1 I counted 4. Let me recount z1: blue heads at crop (230,575), (520,570), (620,530), (690,470). Hmm, looking at z1 image again: I see arrows at approximately (230,575), (520,570), (620,530), (690,470) — yes 4 blue arrowheads pointing up-left toward the fox.

Fox eats: 兔, 旱獭, 鼠 — that's 3 prey. A 4th? 小鸟? Unlikely. Let me trace each of the 4 blue curves:

Blue-1 head (327,742): curve goes down-left to rabbit (317,905). → 兔→狐 ✓ Blue-2 head (423,740): curve goes down-right, U-dips at (613,1043), back up?? No wait. Hmm. Blue-3 head (457,727): curve goes down-right steep to bottom. Blue-4 head (480,707): straight dark line going down-right across to the mouse.

In z1, from head (423,740), the curve descends going right-down... and from head (457,727), another descends... In z3 top-right, TWO curves (brown+blue) U-dip at (617,1047). In z2 left, I also saw brown+blue U-dips.

So: blue curve from fox head (423,740) or (457,727) → down → U-dip near marmot (617,1047) → back up?? That can't be — a U-dip near the marmot and back up would mean the curve connects fox to something above, not to the marmot.

Wait, unless the curve ENDS at the U-dip. Curves with arrowheads at one end: the other end is blunt. If the blue curve goes from fox head (423,740) down-right and its blunt end is at the U-dip near the marmot (617,1047)... but a U-dip means it turns around. Unless what I'm seeing as a "U-dip and back up" is actually the blunt end pointing down toward the marmot.

Look at z3 top-right again: the brown and blue curves come down, reach bottom at crop (1350,790), and appear to turn back up. But maybe what I'm seeing is: the brown curve comes down, its blunt END points down toward the marmot (i.e., starting at the marmot), and it only goes UP from there (the "U" is just the curve bending from vertical-down-blunt-end to up-right). Actually yes! The blunt end of an arrow often points AT the prey. So:

Argh. OK let me be very careful. In z3, top-left: blue+brown curves END at (317,905) near rabbit. In z1, at crop (150-170, 0-220) [original (300-307, 850-923)]: the blue curve descends from the fox (head at 327,742) to the rabbit (317,905). And the brown curve descends from... above (top of z1 crop at (740,160) → original (497,605)?? No wait, that was curve A in z1 which ended in mid-air.

Hmm, hold on. Let me re-examine z1's brown curve A: "one brown curve enters from top (crop (800,0)-(900,150)) and ends at crop (740,160) → original (497,603)". So there's a brown curve whose lower blunt end is at (497,603) — in mid-air between the fox and the eagle. And its upper end goes to the eagle (head at 713,493).

That doesn't make sense unless the blunt end points at... the FOX? The fox's head/nose is at original (467,630). The blunt end at (497,603) is just right of the fox's nose. So this brown arrow = 狐→鹰?!

Wait, that seems ecologically wrong, but let me look at the full picture again. In the grid image, the brown curve with head at (713,493): I see it sweeping from the eagle left-down to (497,603). And (497,603) is right at the fox's open mouth/nose area. Hmm.

Actually, you know what — maybe it IS 狐→鹰? No... Let me look at the ORIGINAL unedited image again around (497,603) and (467,630). Actually in the very first view of the full image, I recall the fox's nose had a small brown curve near it. Let me zoom in tightly on the fox head and the brown curve end.

Now this is very clear! Crop (400-780, 480-720):

So this brown arrow goes FROM the fox area TO the eagle: 狐→鹰?? That's ecologically unusual...

Wait, wait. Let me reconsider. Actually, hmm — maybe the arrow is meant to represent 兔→鹰 but drawn sloppily? No — the blunt end clearly terminates right next to the fox's nose, pointing at the fox.

Hmm, actually, hold on. Let me reconsider the direction. What if this curve actually connects the fox and eagle in the other sense — maybe I should double check whether the arrowhead points toward the eagle or away. In the crop, the arrowhead at (1600,60) → original (720,492) clearly points up-right (the triangular head with point at up-right). The eagle is up-right. So yes: fox → eagle.

Hmm, but that's weird for a textbook. BUT — this might not be a "standard" textbook; some newer textbooks do include 鹰捕食狐? No, eagles don't prey on foxes.

Wait — actually, let me look at the whole picture again. Maybe the blunt end isn't pointing at the fox — maybe the curve continues faintly down to the rabbit? In z5, the blunt end at (496,604) just stops. There's no continuation. The fox nose is at (474,638), 30px away.

Hmm, hmm. But actually, you know what? Let me reconsider: in the ORIGINAL photo, maybe this arrow is 兔→鹰 drawn from the rabbit, passing LEFT of the fox... no, the blunt end is at (496,604), far from the rabbit (320,1040).

OK here's another thought: this could be 狐→鹰 in the sense of the eagle competing with/scavenging? No. Textbook food webs show 捕食 relationships. Some textbook food webs DO include eagle preying on fox kits? Very unusual.

Actually — wait. Let me look at the bigger picture. This image is a HAND-DRAWN or MODIFIED version? The caption says "图3-4 某陆地生态系统的食物网". Let me compare with the actual 2024 人教版 textbook figure. The 2024 new 人教版七年级上册图3-4 might indeed have 旱獭 and 喜鹊. Let me search for the actual textbook figure to compare arrow configurations.

Actually, let me first finish tracing all arrows in THIS image, since the user asked about THIS specific image. Whatever the standard answer is, I should count from the image.

Current findings (arrows = prey→predator):

Blue arrows:

Brown arrows (to eagle): A. 狐→鹰 (head 720,492) — from fox nose. (Need to double-check!) B. ?→鹰 (head 883,552) — from rabbit or marmot (the big U-dip curve) C. ?→鹰 (head 927,593) — from mouse (U-dip at 1017,1067) D. 蛇→鹰 (head 1037,587) — vertical from snake E. ?→鹰 (head 1160,527) — from below right F. 喜鹊→鹰 (head 1173,320) — from magpie G. ?→鹰 (head 1167,350) — from right (spider? frog?) H. ?→鹰 (head 1157,373) — from below (frog? bird?)

Green arrows (to frog/spider/bird):

Let me now systematically verify: (1) the fox-eagle arrow, (2) fox's prey count (3 or 4 blue heads?), (3) snake's incoming arrows, (4) the eagle's right-side arrows E, G, H, (5) magpie's incoming, (6) green arrows, (7) small bird's arrows.

Let me view z4_snake.png next.

This crop (820-1250, 680-950), scaled 4x. The snake is at crop (200-1120, 40-720) → original (870-1100, 690-860).

Blue arrowheads pointing INTO the snake:

So snake has 5 incoming blue arrows! Snake eats: 鼠 (from below), and 4 more from: 旱獭? 兔? 青蛙? 小鸟? 青蛙?

Let me trace each:

Let me trace these right-side blue curves. Crop region (1100-1500, 700-1200) to see where they end.

This crop (1050-1550, 700-1180), 4x. Key observations:

Blue arrowheads pointing LEFT (toward snake):

Wait, actually maybe this curve comes from the small bird or frog, looping up first. Let me follow: head at (1132,740), curve goes right-up steeply, exiting crop top at original ~(1310,700). Above that is... the brown curve region near (1160,527). Hmm.

Actually wait — this might be the curve from the small bird (1440,1130) or the frog. Hmm, but it goes UP, not down.

Hmm, let me look at the second blue head: 2. Crop (280,290) → original (1120,772): curve goes right, slightly down, passing below the frog, exiting crop right at (2000,330) → original (1550,782). Continues right toward the spider (1740,770)?? So 蜘蛛→蛇?? Or it comes from the small bird via a loop?

Hmm wait, actually looking at the curve: from head (1120,772), the blue curve sweeps right and slightly down, passing under the frog at y~782... it exits the crop at right edge (1550,782). Beyond is the spider at (1740,770). So this blue arrow: 蜘蛛→蛇? Hmm, that's odd. OR it could loop down to the small bird first.

Hmm! Interesting. At crop (1390,1390) → original (1397,1047): a BLUE curve comes from upper-left (from snake head (1085,830)) and a BROWN curve goes up-right (exiting crop top-right at (1930,0)?? no...). Let me look: the brown curve on the right side of the crop goes from top (crop (1930,0) area... actually the brown vertical line at crop x~1930 spans the whole height) — hmm, there are TWO brown vertical-ish lines in this crop: at crop x~580 (original ~1195) and crop x~1100 (original ~1325) and crop x~1930 (original ~1532).

Wait, I see: brown line at crop (580, 0-1000) → original x~1195, going from top down to about crop (580,1010) then it curves... hmm no. Let me identify the brown lines:

And the V-point at crop (1390,1390) → original (1397,1047): blue curve comes in from upper-left, brown curve goes up from there. So blue+brown meet at (1397,1047)?? That can't be a junction — arrows don't junction. They must be two separate curves that happen to meet/touch at that point, OR it's one curve changing color (unlikely), OR they cross.

Hmm, wait. Actually maybe: the BLUE curve from snake-head (1085,830) sweeps down-right and its blunt END is at (1397,1047), pointing at... nothing? The small bird is at (1382-1537, 1080-1180) — (1397,1047) is just above the small bird! So the blue arrow's blunt end points at the small bird: 小鸟→蛇 ✓!! The apparent "V" is because the blunt end is tapered.

And the BROWN curve passing through (1397,1047) going up — that's a separate curve (from the small bird up to the eagle): 小鸟→鹰? The brown curve goes from the small bird area up. Let me verify: brown line 3 from (1397,1047) goes up-right to crop top (1470,0) → original (1417,700) and continues up to the eagle (head (1160,527)? or (1157,373)?). Plausible! So 小鸟→鹰 via this brown curve.

Wait, but hold on — brown line 3 passes right of the frog, going up. And there's also brown line 4 at crop x~1930 (original ~1532) vertical. Where does that one go? It might be 蜘蛛→鹰 or 青蛙→鹰. And brown line 1 at crop x~580 (original ~1195): from top down to ~(1195,1010)?? where's its bottom end? Near the mouse (1030,1130)? or the small bird? Hmm, (1195,1010) — closest animal below is the small bird (1382,1080) or mouse (1030,1130). Hmm.

Let me also check: the frog's green arrows. Green heads pointing LEFT into the frog:

These are 蜘蛛→青蛙 and/or 昆虫→青蛙. Need to trace right.

Also is there a blue arrow 青蛙→蛇? The blue heads (1132,740) and (1120,772): one might come from the frog. Head (1120,772)'s curve passed BELOW the frog going right to the spider — hmm, or does it START at the frog? The curve passes under the frog at y~782, frog bottom at y~832. It doesn't touch the frog. So probably not from the frog.

Head (1132,740)'s curve went up-right steeply exiting at (1312,700). Continuing up beyond the crop... Let me extend the region upward. This might come from the eagle area? No. OR it loops from the small bird up and around. Hmm.

Let me crop (1100-1500, 480-780) to trace it.

This crop (1100-1600, 460-800), 4x. Now I see:

Hmm wait, at crop top-right, the blue line is going up-right steeply toward (1600,467). If extended, it would reach the magpie (1700,380). So 喜鹊→蛇?? That's weird. OR it loops from the spider. Let me look at z9_right.png which covers (1450-1920, 450-1250).

Wait, the brown line at crop x~900 goes UP to where? It exits crop top at (900,0) → original (1325,460), continuing up-left to the eagle. Its arrowhead would be one of (1167,350),(1157,373),(1160,527). And its bottom blunt end at (1325,762) points at the frog. So 青蛙→鹰.

Let me now view z9_right.png for the right side details.

This crop (1450-1920, 450-1250), 4x. Now I can see the right side clearly:

Wait, the two green curves both have blunt ends near the insect at (1767,1090)? One goes to the frog (head 1477,840) = 昆虫→青蛙. One goes up to the spider (head 1765,900) = 昆虫→蜘蛛. And the third green (head 1472,767) has its blunt end at the spider (1685,785) = 蜘蛛→青蛙.

So green arrows: 昆虫→青蛙, 昆虫→蜘蛛, 蜘蛛→青蛙. ✓ Classic.

Now, what about the small bird's connections?

In this crop, between the insect and the small bird (both at bottom), I see... the moth at crop (1010-1380, 2670-3050), small bird at crop left edge (0-300, 2650-3100). I don't see a clear arrow between them in this crop — but the crop is cut. Let me zoom the bottom area (1350-1900, 1000-1300) to check insect↔bird connections and the 草 arrows.

Also the magpie: 喜鹊→鹰 (brown head (1173,320)) and what does the magpie EAT? Blue arrows into magpie: 蜘蛛→喜鹊 and 昆虫→喜鹊 (the two blue heads).

Now back to the snake's blue heads:

Actually, let me reconsider: in z9, the blue line with head (1752,542): goes down to blunt end (1757,670) near spider. That's 蜘蛛→喜鹊.

In z8, the blue line (snake head 1132,740) goes up-right to (1600,467) and beyond the crop. In z9, at the top-left corner, there's a blue line entering at crop (0-100, 0-200) → original (1450-1475, 450-500), going up-right. Yes! In z9 top-left, I see a blue line crossing the corner. That connects z8's blue line: from snake head (1132,740) up-right through (1600,467), continuing up-right... to the magpie? That would mean 喜鹊→蛇?? Weird. OR it bends down to the spider: 蜘蛛→蛇?

Hmm, wait. Let me look at z9 top-left again: there's a blue line at crop (0,150)-(250,0) → original (1450,487)-(1512,450). And in z8, the blue line exited at (1600,467). So the blue line continues from (1512,450) to (1600,467)?? That's going down-right slightly. Then in z9, does it continue? At crop (250,0) it exits the top → original (1512,450) going up. Beyond: toward the eagle/magpie region (1500-1700, 380-450). Hmm, the magpie is at (1700,380).

This blue curve might actually be 蜘蛛→蛇: from the spider (1740,770), the curve goes UP-LEFT... no. Hmm, I'm confusing myself.

Let me trace this specific blue curve with a dedicated crop covering (1100-1800, 400-780).

This crop (1100-1800, 380-780), 4x. Now I can trace the blue curve from the snake:

So: 喜鹊→蛇?! The snake eats the magpie? Hmm, that's unusual but snakes DO eat birds. In a textbook food web, 蛇吃鸟 is plausible.

Wait, but hold on — is the blunt end really pointing at the magpie? The blue curve ends at (1692,425), right below the magpie's branch. Yes. So 喜鹊→蛇.

Hmm wait, but that seems odd — actually in some textbook food webs, 蛇 does prey on birds. OK.

But wait — then what about the two blue arrows INTO the magpie (蜘蛛→喜鹊, 昆虫→喜鹊)? Those are separate.

Now let me also verify the second blue head (1117,772): curve goes right toward the spider. In this crop, at bottom-left, blue head at crop (60,1560) → original (1115,770), curve goes right along the bottom (y~770-790), passing above the frog... its right end? In the previous z8, it exited at (1600,792). In z10 crop (which ends at y=780), I'd need to see below. From z6 earlier: the curve passed below the frog exiting at (1550,782), continuing to the spider (1740,770). So 蜘蛛→蛇.

Hmm wait, but let me double check — in z9_right, was there a blue line from the spider going LEFT to the snake? In z9, I saw the spider with green arrows and the blue curve going down from the magpie to the spider's top (blunt end at (1757,670)). I didn't see a blue line leaving the spider toward the left. But the blue curve at y~782 in z6 clearly continues right past (1550,782). Let me verify its right end — crop (1450-1800, 720-830).

Also remaining to verify:

Let me view z7_snakeleft.png now.

This crop (600-950, 700-1000), 5x. The blue arrowhead at crop (1290,220) → original (858,744) points up-right toward the snake's tail. Its curve goes down-left, exiting the crop at bottom-left (crop (130,1500) → original (626,1000)). Continuing down-left toward... the marmot (620,1120)? So this is 旱獭→蛇? Or it continues to the rabbit?

Hmm wait, the curve from head (858,744) goes down-left. At crop left edge (0,750) → original (600,850)... it curves down. Let me follow it in the larger context: In z2_center (550-1150, 850-1250), there was a blue curve from the top-left going down to the U-dip near the marmot at (613,1043)? Actually in z2 I saw at top-left "a brown line entering from top-left corner (crop (100,0)) going down, curving at bottom (crop (190,580))" — original (583,850) down to (613,1043).

Hmm, so both a brown curve and a blue curve dip near the marmot at (583-617, 1043-1050).

Wait, I need to carefully separate: near the marmot, how many curve-ends point at it? The marmot is eaten by whom? Likely 狐 and 鹰 (both plausible for a marmot). Does the snake eat the marmot? Snakes could eat young marmots, but in textbook webs, usually not.

Let me carefully crop the region above the marmot (560-700, 950-1130) at high zoom to see exactly which curves terminate at the marmot and their colors/directions.

This crop (540-780, 950-1150), 8x. Above the marmot's back (marmot top at crop y~1020 → original y~1077):

At crop (610,750) → original (616,1044): the brown curve and blue curve meet at a tapered point pointing DOWN at the marmot. Wait — actually it looks like the brown curve comes from the left-up, bends down to the point at (616,1044), and the blue curve goes UP from that point (two blue lines going up, diverging). Hmm.

Actually looking carefully: there's ONE blunt point at (616,1044) pointing down toward the marmot's back (gap of ~30px). From that point:

Hmm, so it seems like TWO arrows have their blunt ends at the same point near the marmot: one brown (旱獭→鹰) and one blue (旱獭→狐 or 旱獭→蛇). The blue going up splits? No — the two blue lines going up are probably: one is the 旱獭→狐 (going up-left to fox head (423,740)) and one is 旱獭→蛇 (going up-right to snake head (858,744))? But they share the same blunt end?? That can't be — they'd be two separate arrows with nearby blunt ends.

Actually wait. Let me reconsider. Maybe: the brown curve passes THROUGH this point (it's the 兔→鹰 curve dipping down, with the rabbit on the other side). Recall the 兔→鹰 brown curve: from rabbit (317,905) sweep right to U at (583,1050) then up-right to eagle (883,552). The U-bottom was at (583,1050)... but here the brown bends at (616,1044). Hmm, slightly different location. Maybe the brown curve's lowest point is around (583-616, 1044-1050) — consistent, it's the same curve. So the brown does NOT terminate at the marmot — it just dips near it! The brown curve = 兔→鹰 (from rabbit, dipping near marmot, up to eagle).

And the BLUE line(s) going up from (616,1044): the blue curve has its blunt END at (616,1044) pointing at the marmot = 旱獭's predator. Going up: one blue line. But I see two parallel lines — maybe it's the same line's edges (thick line), or two close lines. The blue goes up to... the snake head (858,744) per z7 trace, or the fox head (423,740)?

In z7, the blue curve from snake head (858,744) went down-left to (626,1000) and beyond. (626,1000) → continuing to (616,1044)? Yes! That connects. So 旱獭→蛇?? Hmm, snake eats marmot?

But wait, also in z1, a blue curve from fox head (423,740) went down-right to the bottom of z1's crop at original (613,1047). That ALSO connects to (616,1044)! So is there one blue line from fox to marmot and another from snake to marmot, both ending at the same point (616,1044)?

Hmm, that would give the marmot TWO predators with arrows ending at the same spot. Possible but unusual drawing.

Let me count blue lines going UP from the point (616,1044) in z11: I see what appears to be TWO blue lines diverging upward: one more vertical (exiting top at (620,0) → original (617,950)) and one going up-right (exiting top at (870,0) → original (649,950)).

The up-right one at original (649,950): continuing up-right... to the snake (858,744)? From (649,950) to (858,744): direction up-right. Yes plausible → 旱獭→蛇. The vertical one at original (617,950): continuing up... to the fox head (423,740)? From (617,950) up-left to (423,740)? Hmm, that's up-LEFT. But the line exits going straight up. Let me check where it goes — in z1, the blue curve from fox head (423,740) descended down-right and reached (613,1047). So from the marmot's perspective, the blue line goes UP-LEFT to the fox. So 旱獭→狐 ✓.

And the brown: 兔→鹰 passes through (616,1044) region (dipping). Wait, but in z11 the brown line ends/bends exactly at the same point (616,1044) as the blue. Does the brown terminate at the marmot too (旱獭→鹰)?? If the brown's lowest point is exactly at (616,1044) with a tapered look pointing down at the marmot, then 旱獭→鹰 also holds.

Hmm. This is genuinely ambiguous. Let me look at z11 again: the brown line comes from upper-left, reaches (616,1044), and... does it continue up-right? In the crop, from point (610,750), I see the brown going up-left, but I do NOT see brown going up-right from that point. The lines going up-right are BLUE. So the brown TERMINATES at (616,1044)!!

But wait — that contradicts my earlier trace of the 兔→鹰 brown curve through (583,1050) up to eagle head (883,552). Let me re-examine: in z1, the brown curve B entered at (325,897) [rabbit] and swept down-right... In z3, the brown ended at the rabbit (317,905). In z11, brown terminates at (616,1044)??

Hold on, maybe there are TWO brown curves here: one from the rabbit to the marmot-dip (terminating), and one from the marmot-dip up to the eagle. I.e., 兔→鹰 is actually... no. Arrows are single curves from prey-blunt-end to predator-head.

Hmm, wait. Actually maybe I misread z1. Let me re-look at z1's brown curve B: it entered the crop at left-bottom (225,1040) → original (325,897) [near rabbit], swept down-right to U at (583,1050), then went up-right exiting at (780,683). So the SAME brown curve goes rabbit → dip(583,1050) → up to eagle. If that's one continuous curve, then the brown does NOT terminate at the marmot; it passes by.

But in z11 (540-780,950-1150), at point (616,1044), the brown comes from up-LEFT and ends. From up-left means from (577,950) and beyond up-left. If the brown curve comes from the rabbit (317,905), it would approach the dip from the LEFT-BELOW (from (317,905) going right-down to (583,1050)), i.e., approaching (616,1044) from the left side, not from up-left.

In z11, the brown enters from crop top-left (300,0) → original (577,950). So coming from above-left. Hmm, that means the brown curve comes down from (577,950) to (616,1044). And from (577,950) further up-left... in z3 (280-700,850-1160), at top-right I saw brown+blue descending to U at (617,1047). The brown descended from crop top (1230,0) → original (587,850). So brown path: (587,850) → (577,950) → (616,1044) dip → then up-right? In z11 I couldn't see brown going up-right clearly, but in z1 I saw it going up-right to (780,683).

Wait, z1's crop was (250-780,550-1080) and the brown curve B's right exit was at crop (1590,400) → original (780,683). And z1's brown U bottom at crop (1000,1500) → original (583,1050). So the brown: (325,897) → (583,1050) → (780,683) → up to eagle head (883,552).

And z3 showed brown+blue descending from (587,850) to U at (617,1047)??

CONTRADICTION: z1 says brown passes (325,897)→(583,1050)→(780,683); z3 says brown descends (587,850)→(617,1047).

Resolution: there might be TWO brown curves in this area:

Hmm wait, but z11 shows brown terminating at (616,1044) coming from up-left. And z3 shows brown+blue descending together from top to (617,1047). If brown-2 comes down from up-left and terminates at the marmot, and brown-1 passes through (583,1050) separately...

The two points (583,1050) and (616,1044) are 33px apart — could be two separate dips! Brown-1 dips at (583,1050) [passing, rabbit→eagle], and brown-2+blue terminate at (616,1044) [marmot→eagle and marmot→?].

Hmm, but in z11, I only saw ONE dip point at (616,1044). And in z11's field (540-780 x, 950-1150 y), brown-1's dip at (583,1050) should also be visible... In z11, at original (583,1050) → crop (344,800): hmm, in the crop at (344,800), that's left of the visible brown line? The brown line in z11 passes crop (450,500)-(610,750). At crop (344,800)... nothing there? Maybe brown-1's dip is actually the same as what I see.

I think I'm overanalyzing pixel positions from memory. Let me do a definitive trace: extract the brown lines as a skeleton and label connected components. Since brown lines are distinct from animals (animals are darker/more saturated), let me refine the mask and do connected component analysis to count distinct brown curves and their endpoints.

My sample points aren't hitting the lines precisely (the lines are thin, ~2-3px). Let me take a different, more reliable approach: instead of pixel-perfect automated extraction, let me carefully do manual tracing on a large, high-quality rendering of the whole web, marking coordinates. I'll view specific curve segments at high zoom and follow each curve end-to-end.

Actually, a better idea: let me use edge-aware color sampling. For each brown curve, I'll click along it manually using crops. But that's what I've been doing.

Let me instead search for the actual textbook figure online to get the authoritative arrow configuration. The caption "图3-4 某陆地生态系统的食物网" — this is likely from 2024人教版《生物学》七年级上册. Let me search images for it.

The search didn't find the exact standard answer for this specific figure. This is a modified/extended version of the classic food web (some teacher-made or exam-modified version with added 旱獭/喜鹊/小鸟). I must count from the image itself.

Let me now be extremely systematic. I'll establish the definitive list of arrows by tracing each curve with targeted zooms. Let me build a master diagram and verify each relation:

Definite so far:

That's a lot. Let me now verify the remaining uncertain ones with targeted crops: A. Fox's blue heads: exactly 3 or 4? Sources: 兔, 旱獭, 鼠? B. Snake's left head (858,744): from 旱獭? C. Marmot dip: which lines terminate there (brown? blue?) → 旱獭→鹰? 旱獭→狐? D. Mouse dip (1017,1067): brown → 鼠→鹰? blue → 鼠→蛇? E. Brown head (1160,527): from 小鸟? F. Brown head (1167,350) and (1157,373): from 蜘蛛/青蛙? G. 昆虫→小鸟?

Let me check z12_mouse.png first (was saved).

This crop (930-1180, 950-1160), 8x. Above the mouse (mouse top at crop y~1180 → original y~1097):

At crop (690,940) → original (1016,1067): a V-point where:

Let me re-read: at the V-point (1016,1067):

Hmm wait, in z2_center, I saw the brown curve from the mouse-dip going up-right (exiting z2 right at (1150,950)). And separately the brown head (927,593) came from below. Let me trace the brown from the mouse V-point (1016,1067) upward: it goes up-right to (1140,950), then continues up... In the mid.png overview, there was a brown curve from the mouse area going up-right to the eagle's heads at (927,593)? Hmm.

Wait, actually, in the masks2.png image, I recall the brown curve with head (927,593) went down to (1000,1050) near the mouse. Let me confirm: brown head (927,593) traces down...

Ugh. OK, let me take a cleaner approach for the eagle's 8 brown arrows: trace each head's curve downward:

Head (713,493) → fox nose. = 狐→鹰 ✓ (confirmed in z5) Head (1037,587) → straight down to snake. = 蛇→鹰 ✓ (confirmed z4) Head (1173,320) → right to magpie. = 喜鹊→鹰 ✓ (confirmed eagle.png/z10) Head (1160,527) → brown line going down at x~1195 → to where? (z8 showed it going down past y=800) Head (1157,373) → brown line going down at x~1325 → blunt at frog (1325,762) = 青蛙→鹰 (z8) Head (1167,350) → brown line going down-right at x~1530 → to spider? (z8/z9) Head (883,552) → down-left → to rabbit (big sweep) = 兔→鹰 (z1) Head (927,593) → down → to mouse = 鼠→鹰 (need confirm)

And the marmot brown dip (616,1044): goes up-left → which head? Possibly (927,593)? or (883,552)?

Wait, I previously thought (883,552) came from the rabbit. Let me re-verify: in z1, brown curve B went from rabbit (325,897) → dip (583,1050) → up-right exiting z1 at (780,683) → continue up to... (883,552)? From (780,683) to (883,552): up-right. Yes, that's consistent — 兔→鹰 head (883,552).

Then head (927,593): from below. In z1/z2, the mouse V at (1016,1067) has brown going up-right to (1140,950). Hmm, from (1140,950) up to (927,593)? That path would go up-left. Let me check if there's a brown line from (1140,950) up to (927,593) — passes (1050,750)? The snake is at (870-1100, 690-860). Hmm, would cross the snake. In z4 (snake crop 820-1250,680-950), was there a brown line crossing? In z4 I saw a brown vertical line at crop (835,0-230) → original (1027,680-737) — that's the 蛇→鹰 vertical (head 1037,587). And another brown line at crop right edge (1700,300-1080) → original (1245,755-950)?? That's the x~1195 brown line (head 1160,527).

Hmm OK so near the snake's right, brown lines at x~1195 and x~1245? Let me map the brown lines going down from each eagle head with fresh dedicated crops. I'll trace:

Crop vertical strips: (1100-1250, 500-1080) for head (1160,527); (920-1000, 550-1100) for head (927,593).

This vertical strip (1120-1280, 500-1100), 8x. The brown line from head (1160,527) [crop (310,200)] goes down:

At original (1190,1100): what's there? The small bird is at (1382-1537, 1080-1180) — (1190,1100) is left of the bird. The mouse is at (983-1083, 1100-1200). Hmm, (1190,1100) is between the mouse and the small bird, in empty space.

Wait, but earlier in z6, I saw the brown line dip to the V-point at (1397,1047) near the small bird, then go up. Is this the same line? The line in z13 exits at (1190,1100) heading down. Below y=1100... let me extend the crop down to y=1250 to see where it ends. It might curve right toward the small bird (1440,1130).

Also note: in z13, the brown line is at x~1159 at top (y=525) and drifts right to x~1190 at y=1100. Continuing the drift, it might reach x~1230-1250 at y~1200. The small bird's left edge is at ~1382. Hmm, still far.

Alternatively it might end pointing at... hmm. Let me just extend the crop.

This crop (1100-1500, 1000-1250), 6x. I see:

Wait, so where does the brown line from head (1160,527) END? In z13 it exited at (1190,1100) going down. In z15 (1100-1500, 1000-1250), I should see it... at crop x~ (1190-1100)*6=540, y~(1100-1000)*6=600. Looking at crop (540,600)... hmm, I don't see a clear brown vertical line there. The brown at top-right is at crop x~1900-2400 (original 1417-1500).

Hmm, so the brown line from (1160,527) that was drifting right... in z13 it went from (1159,525) down to (1190,1100). In z15, at (1190,1100) → crop (540,600) — I don't see it continuing. Maybe it ended at (1190,1100)?? That's empty space (between mouse and bird). OR it curved right and became the brown line at (1417,1000)?

Wait — maybe the brown line from head (1160,527) curves RIGHT and connects to the V-point near the bird at (1395,1045), then continues up as the brown at (1417,1000)?? No wait, that doesn't make sense — a curve from the eagle going down to the bird, then going back up to the eagle?

Let me reconsider. Perhaps there are TWO brown lines near the small bird:

Hmm, wait. In z6, I saw: "a BLUE curve comes from upper-left (from snake head (1085,830)) and a BROWN curve goes up-right from the V-point (1397,1047)". So at the V-point (1397,1047): blue ends (小鸟→蛇) and brown passes/starts going up.

And in z15, the blue curve's blunt end is at (1395,1045) pointing at the bird, and the brown line goes up from ~(1417,1000).

So the brown line going up at x~1417 from the bird area: 小鸟→鹰! Its head would be one of the eagle's brown heads. Going up at x~1417... in z8 (1100-1600,460-800), there was a brown line at crop x~1720 → original ~1530 vertical. Hmm, that's x~1530, not 1417. And another at x~1325 (blunt at frog).

Wait, in z8: brown lines at crop x~380 (orig ~1195, head (1160,527)), crop x~900 (orig ~1325, blunt at frog bottom (1325,762)), crop x~1720 (orig ~1530, vertical full height). So the brown from the bird (x~1417 at y~1000) drifts right to x~1530 by y~460-800? Possible — a long curve. Then its head = (1167,350) or (1157,373)?

Ugh, wait. Let me carefully map the eagle's right-side brown heads to their downward lines:

In eagle.png (crop 900-1750, 250-700), the 3 heads at top-right: (1173,320), (1167,350), (1157,373). Their curves:

Hmm wait, heads (1160,527) AND (1157,373) are both on steep downward lines? In eagle.png, from head (1157,373) the line went down-right crossing the blue line, at x~1200-1250 going down. And head (1160,527)'s line also goes down at x~1160-1190. These are two separate parallel lines going down on the right side of the eagle.

And in z8, going down at original x~1195 (head (1160,527)? or (1157,373)?) and x~1325 (blunt at frog) and x~1530 (vertical).

Hold on, in z8 I identified: brown at orig x~1195 with head (1160,527) at top; brown at x~1325 fading at (1325,762) near frog — going UP to which head? It exited z8 top at (1325,460) heading up → head (1157,373)? From (1325,460) up to (1157,373): up-left, plausible. So 青蛙→鹰: blunt at frog (1325,762) → up → head (1157,373). ✓

And brown at orig x~1530 vertical (z8, full height): from where to which head? It exited z8 top at (1530,460) → up to head (1167,350)? From (1530,460) to (1167,350): up-left, plausible. And its bottom: z8 ended at y=800; in z9 the brown at crop x~290-330 → original ~1522-1532 continued down through the spider area to...? In z9, the brown line at crop x~300 (orig ~1525) ran from top to bottom of the visible area, passing the spider's left, down past (1525,1250). Below that → toward the small bird (1440,1130)?? or insect (1740,1160)?

Hmm wait, in z9 the brown line passed at crop (300, 2450) → original (1525,1062), and continued down to crop (300,3200)?? The crop z9 was (1450-1920,450-1250), so bottom is y=1250 → the brown exited at (1525,1250) heading down. Below y=1250: the grass. Hmm, where does it end? The small bird is at (1383-1500,1080-1217). The brown at x~1525 y~1250 is below-right of the bird.

Hmm, wait — but in z15 I saw the brown at top-right (1417-1500, 1000-1025). That's at y~1000-1025. And z9's brown at x~1525 spans y~450-1250. So actually maybe these are the SAME brown line: it goes from head (1167,350) down at x~1530 (z8, y460-800), continues down (z9, y800-1250 at x~1525)... and ALSO passes (1417-1500,1000)? No — z9's brown at y~1000 was at x~1525, but z15's brown at y~1000-1025 was at x~1417-1500. Close enough — same line drifting. OK.

So this brown line (head (1167,350)) descends from the eagle down the right side at x~1500-1530, passing left of the spider, down to y~1250, ending near... hmm, where? If it ends at (1525,1250) that's below the small bird (bird bottom ~1217). Near the bird's feet? The 草→小鸟 blue head was at (1385,1193).

Hmm, actually — maybe this brown line's blunt end points at the small bird from the right side = 小鸟→鹰! And then what about the brown line from head (1160,527) that descended at x~1160-1190? Where does THAT end?

In z13, it exited at (1190,1100) heading down-right. In z15 crop (1100-1500,1000-1250), at (1190,1100) → crop (540,600): I don't clearly see it. Maybe it faded or curved. Let me look at z15 again... Actually in z15, at the very top-left corner there was a brown stub (crop (0-60,0-40) → orig (1100-1110,1000-1007)). Hmm, that's at x~1105, not 1190.

Let me directly crop (1150-1250, 1080-1250) to find where brown line (head 1160,527) ends.

This crop (1130-1420, 1050-1300), 8x. I see:

I do NOT see the brown line from head (1160,527) in this crop — it should pass through around (1190-1230, 1100-1300) if it continued down. It's not visible. So the brown line from head (1160,527) must have ENDED around (1190,1100) or curved right to join the V-point near the bird.

Hmm, wait. Actually, let me reconsider — maybe the brown line from (1160,527) curves right and its blunt end is at the V-point (1395,1045) near the small bird, sharing the spot with the blue 小鸟→蛇 blunt end. In z6, at the V-point (1397,1047), I saw blue coming from upper-left and brown going up-right. If instead: brown comes from upper-left (from (1160,527) down) AND blue comes from upper-left (from snake head (1085,830)), both ending at the V-point near the bird, and brown ALSO goes up-right (another arrow, 小鸟→鹰 via the x~1530 line)...

So possibly TWO brown arrows involve the bird:

No, that's redundant — two arrows for the same relation. Unlikely.

Alternative: the x~1530 brown line (head (1167,350)) goes down to the SPIDER (1740,770) or the INSECT (1740,1160)? In z9, it passed left of the spider at x~1525 (spider at x~1700-1807). Hmm, it didn't touch the spider. It continued down past y=1250.

Wait — maybe the x~1530 brown line ends at the small bird after all (bird at 1383-1500,1080-1217; the line at x~1525 is just right of the bird's tail). The bird faces left (head at left). Its tail is at right ~(1500,1150). The brown line at x~1525, y~1100-1250 passes just right of the tail. Plausible blunt end for 小鸟→鹰.

And the brown from head (1160,527) descending at x~1160-1190: maybe it curves right at the bottom and reaches the bird's left side (head side, (1383,1100))? In z6 I saw brown going up-right from the V-point (1397,1047).

Hmm, hold on. Let me re-examine z6 carefully: "at crop (1390,1390) → original (1397,1047): BLUE curve comes from upper-left, BROWN curve goes up-right (crop (1420,1390) upward to (1470,0))". So brown goes UP-RIGHT from the V-point, at x~1417-1470 going up (this becomes the x~1530 line higher up). And z13's brown (head 1160,527) came down at x~1160-1190 and... did it reach the V-point? In z6 crop (1050-1550,700-1180), a brown line at crop x~580 → original ~1195 went from top down to crop (540,1010)?? → original (1185,952)... and z6 also showed the brown crossing the blue at crop (540-580, 950-1010). Hmm.

You know what — let me just accept some uncertainty here and think about what makes ecological/textbook sense, then verify against the overall arrow count.

Actually, wait. Let me step back and reconsider the brown heads count. Maybe I overcounted. Let me re-examine the eagle's right-side heads in eagle.png: heads at (1173,320), (1167,350), (1157,373) — three heads clustered. And (1160,527), (1037,587), (927,593), (883,552), (713,493). Total 8.

Sources identified:

Candidate sources for the 3 unknowns: 鼠 (mouse), 旱獭 (marmot), 青蛙 (frog), 小鸟 (bird), 蜘蛛 (spider).

The marmot dip (616,1044) had a brown line going up-left — that connects to which head? Going up-left from (616,1044): through (577,950),(587,850), continuing up... to (927,593)? From (587,850) to (927,593): up-RIGHT. Hmm, or to (883,552)? Also up-right. Or to (713,493)? up-left-ish.

Wait, I previously assigned (883,552) to the rabbit sweep. Let me double check by re-examining z1: the brown curve B from the rabbit (325,897) swept right-down to (583,1050) then up-right exiting at (780,683). Continuing from (780,683) up-right: to (883,552)? Direction (780,683)→(883,552) = (+103,-131). Yes. So (883,552) ← 兔.

And the marmot-dip brown at (616,1044): wait, but the rabbit sweep ALSO passes through (583,1050) which is ~33px from (616,1044). Are there really two brown dips? In z11 (540-780,950-1150, 8x), I saw only ONE dip point at (616,1044) with brown from up-left terminating/turning. Let me look at z11 again... In z11, the brown came from crop top-left (300,0) → orig (577,950) and bent at (616,1044) going down-point. And the blue went up from (616,1044). I did NOT see brown continuing up-right from (616,1044) in z11. But z1 showed brown from rabbit sweeping to (583,1050) and going up-right to (780,683).

Hmm, (583,1050) vs (616,1044): in z11's crop (540-780,950-1150) at 8x, (583,1050) → crop (344,800); (616,1044) → crop (608,752). In z11, was there brown at crop (344,800)? Looking at z11 image: the brown line enters from top at crop (300,0), descends slightly right to the bend at crop (610,750). I don't recall seeing any brown at crop (344,800). So the rabbit-sweep brown's lowest point might actually BE (616,1044)?? But then it wouldn't continue up-right...

Wait, unless the rabbit-sweep brown goes: rabbit (317,905) → right-down → dip at (616,1044) → up-right to eagle (883,552). Then at the dip (616,1044), the brown should go up-LEFT (toward rabbit) and up-RIGHT (toward eagle). In z11, I saw brown going up-left (to (577,950)?? hmm, that's the direction toward (587,850), not toward the rabbit (317,905)).

Confusion arises because there might be TWO brown lines very close: (a) rabbit→eagle passing through, (b) marmot→eagle terminating. Given the resolution, let me do a very wide, very high zoom of the whole marmot-rabbit-eagle corridor in one image: crop (280-950, 480-1160) at 2x and trace all brown lines.

EXCELLENT! This corridor view (280-980, 480-1170, 3x) is very revealing! Now I can see clearly:

Brown arrows (orange, pointing up-right toward eagle):

Wait, wait, wait. Hmm. Actually — look at the fox: its mouth is OPEN and the brown curve's end is right there. Hmm, but ecologically eagles don't eat foxes. But the drawing clearly shows this arrow from the fox. Hmm. Let me note this and reconsider later. Actually, maybe the intended reading: this is 狐→鹰. OK whatever the ecology, the drawing shows an arrow from fox to eagle.

Hmm, actually hold on. Let me reconsider: could the arrow point FROM the eagle TO the fox? The head is at (717,500) pointing up-right. So the arrow points toward the eagle. 狐→鹰.

Wait — actually, looking at the V-dip at crop (1010,1680): there's a brown line coming from upper-left (from fox direction, descending), dipping, and going up-right to head (937,603). Hmm, and there's ALSO a blue line dipping at nearly the same point (crop (1010,1700)) going up-left to the fox and up-right...

Let me carefully read the blue arrows in this corridor view: Blue arrowheads visible:

So FOUR blue heads at the fox: (327,740), (423,740), (460,720), (483,700). Sources: rabbit, marmot, mouse, and...?

The blue curves from heads (423,740) and (460,720) both go down-right. One dips at the marmot V (617,1040) = 旱獭→狐. The other continues down-right... to where? In this crop, the blue line from head (460,720) goes down-right crossing to crop bottom around (850,2070) → original (563,1170)?? and continues. Hmm, or it might dip at the marmot too.

Actually wait, in this crop I see: from the two middle fox heads, two blue lines descend. They cross near crop (950,1180). One continues down to the marmot V-dip at crop (1010,1680). The other continues down-right, exiting crop bottom at ~(700,2070)?? hmm, or maybe both dip at the marmot?

Hmm, and there's also the blue line going up-right with head at crop (1710,780) → original (850,740) — that's the snake's left head (858,744) = pointing at the snake. Its curve comes from lower-left, dipping at the marmot V (1010,1680). So 旱獭→蛇 ✓!

And the blue line dipping at marmot V going up-left to fox = 旱獭→狐 ✓.

So the marmot V-dip at (617,1040) has: brown (旱獭→鹰), blue (旱獭→狐), blue (旱獭→蛇)?? That's 3 arrows from the marmot. Hmm, wait, let me recount the lines at the V-dip in this corridor crop:

At the V-dip around crop (1000-1020, 1670-1700):

Ugh. Let me carefully separate the two brown lines in this crop: Brown line α: from crop (0,1270) [rabbit (280,903)] going up-right, passing crop (950,1150), head at crop (1830,240) → (890,560). This is 兔→鹰. It does NOT dip at the marmot; it passes well above the marmot.

Wait, but earlier (z1) I thought the rabbit brown dipped at (583,1050). In this corridor crop, the 兔→鹰 brown from (280,903) goes up-right fairly directly (slight curve), passing crop (950,1150) → original (597,863) — no dip to y=1050. OK so I misread earlier. Fine: 兔→鹰 is a smooth long curve. ✓

Brown line β: from the marmot V-dip at crop (1010,1680) → original (617,1040), going up-right, head at crop (1970,370) → original (937,603). This is 旱獭→鹰. ✓

But wait — does brown line β extend left of the dip? In the crop, at the dip (1010,1680), the brown comes from... the upper-left? I see a brown line descending from crop (900,1240) to the dip. That brown line comes from up-left — it's the 兔→鹰 line α passing? Line α at crop x~900 is at y~1200 (passing (597,863))... hmm, actually α passes through (900,1200) region. So near the dip, both α (passing) and β (starting) are close together. The brown I see "descending from up-left to the dip" might be line α passing by, and β starts at the dip going up-right.

OK so to summarize the corridor:

In the corridor crop, from head (460,720) [crop (540,720)], a blue line descends down-right... and from head (423,740) [crop (430,780)], another descends. One dips at marmot V (617,1040). Where does the other go? It should end at some prey. The remaining unassigned prey eaten by fox could be... 小鸟? 鼠? Let me trace: in the corridor crop, the blue from head (460,720) descends steeply, crossing the 旱獭→蛇 line, exiting crop bottom at around crop (700,2070) → original (513,1170)? That's left of the marmot... hmm, or does it dip at the marmot too?

Actually — wait. Maybe fox eats FOUR animals: 兔, 旱獭, 鼠, 小鸟? Hmm, or the 4th blue head at the fox comes from the mouse too? No...

Let me trace the 4th blue line beyond the corridor crop. It likely goes to the small bird (1440,1130). Let me crop the region (480-1450, 700-1200) wide to follow both blue lines from fox heads (423,740) and (460,720).

This crop (400-1500, 700-1210), 2.5x. Now the full blue-arrow picture is clearer:

V-dips (blunt ends near prey):

Wait, so at the mouse V-dip (1016,1068), there's a BROWN line going up-right. Where does it go? In this crop, from the dip (1540,920), the brown goes up-right... exiting crop top at around (1900,0)?? Hmm, the brown lines at the top of this crop: vertical brown at crop (1570,0-100) → original (1028,700-740) [that's 蛇→鹰]; brown at crop (1990,0-500) → original (1196,700-900) [that's the (1160,527) head's line, 小鸟→鹰?]; brown at crop (2300,0-1275) → original (1320,700-1210) [long brown curve]; brown at crop (2650,300-1275) → original (1460,820-1210).

Hmm, wait. Let me map the brown lines in this crop:

Wait, that changes my earlier hypothesis. So the brown line at x~1195-1196 (which I traced in z13 from head (1160,527) down to (1190,1100)) actually continues to the MOUSE dip (1016,1068)?? But (1016,1068) is at x=1016, and the line was at x~1190-1196. Let me re-examine: from mouse dip (1016,1068), brown goes up-RIGHT to (1100,1000), (1196,900), (1196,700), then up to head (1160,527). Yes! A smooth curve. So 鼠→鹰, head (1160,527). ✓

Hmm wait, but in z12_mouse.png, I saw the brown going up-right from the mouse V at (1016,1067) exiting at original (1140,950). Consistent. ✓

Wait, in z8 I observed the brown line at x~1325 "fading around (1325,762) near the frog's top-left". But in z19, the brown-3 curve clearly continues down from (1320,820) to the bird dip (1384,1044). So it does NOT end at the frog — it passes near the frog and continues to the bird. So brown-3 = 小鸟→鹰, from bird dip (1384,1044) up along x~1320 to head (1157,373)? Let me verify the head: in z8, brown x~1325 exited top at (1325,460) heading up-left toward (1157,373) or (1167,350).

Wait — maybe brown-4's blunt end is at the bird's TAIL? The bird image extends to x~1500 (tail). Brown-4 at x~1500, y~1210 is right below the bird's tail. So 小鸟→鹰 via brown-4 too?? Two arrows bird→eagle? That can't be right.

Alternatively brown-4 = 蜘蛛→鹰: but it passes LEFT of the spider (spider at x~1700-1807), at x~1460-1525. Doesn't touch the spider.

Hmm, OR brown-4 dips down and curves LEFT to the bird dip (1384,1044)? Let me look at z19 again: at the bird dip (2460,860), I see blue going up-left and brown going up-right (brown-3). Brown-4 is separate, further right at x~2650crop. Brown-4 goes from top (2650,300) down to bottom (2750,1275) — slightly drifting right as it descends. It does NOT connect to the bird dip.

So brown-4: from head (1167,350) down the right side to ~(1500,1250). Blunt end near... nothing? Unless it continues below y=1210. In z9 it reached y~1250 at x~1525. Let me check below y=1250: crop (1400-1600, 1200-1350).

Hmm wait, actually — maybe brown-4 ends at the bird after all. The bird in z19 is at crop (2460-2750, 950-1275) → original (1384-1500, 1080-1210). The bird's tail/bottom-right is at (1500,1210). Brown-4 ends right there at (1500,1210). So brown-4 = 小鸟→鹰 with blunt end at the bird's tail, and brown-3 = 小鸟→鹰 with blunt end at the bird's head-dip? Two arrows for bird→eagle is redundant...

Unless brown-3 is 青蛙→鹰 (passing by the bird dip but not terminating there)! Let me re-examine: does brown-3 actually connect to the bird dip, or just pass near? In z19, at the bird dip (2460,860): I see the blue V (小鸟→蛇) and brown-3 passing through the same point going up-right. Hmm, they seem to share the point. But maybe brown-3 passes the point and its true blunt end is at the frog (1325,762)? But z19 shows brown-3 continuing DOWN from (1320,820) to (1384,1044) — so it goes BELOW the frog level, to the bird dip. If it terminated at the frog, it would stop at y~762.

Ugh. OK let me think about this differently. Maybe:

Hmm, wait. Actually, maybe brown-4 goes down to the INSECT (1740,1160)? In z9, brown-4 (x~1525) passed the spider's left at y~770-855, and continued down to y~1250 at x~1525. The insect is at x~1700-1795. If brown-4 curves right below y=1250 toward the insect... let me check crop (1450-1800, 1180-1350).

Also still need: does 食草昆虫→小鸟 exist (green or blue)? Let me view z17_bottom.png which I saved earlier.

This crop (1300-1900, 1080-1300), 4x. I see:

Importantly: I do NOT see a green or blue arrow directly from the insect to the small bird (昆虫→小鸟). The bird's arrows: 草→小鸟 (blue head at its feet). No arrow from the moth to the bird visible here.

So the small bird eats GRASS (草→小鸟)?? That's what's drawn. OK — the bird is a primary consumer here (like a sparrow eating seeds). Interesting. And it's preyed by 蛇 and 鹰.

Now, remaining uncertainties:

Hmm, wait. Let me recount the fox's blue heads in z19 (top-left corner): heads at crop (50,90),(130,70),(190,30) → original (420,736),(452,728),(476,712)... plus the (327,740) one is off-crop left. Hmm, in z19 I see 3 blue heads at top-left + the curvy rabbit one off-crop. So 4 total fox heads: (327,740), (420,736), (452,728), (476,712).

Blue lines descending from these heads in z19:

In z19, I see TWO long steep blue diagonals: one from (452,728) area going down-right passing near the mouse... and one from (476,712) going down-right even further, crossing to... let me see: the straightest steepest one passes crop (700,1275)?? no. In z19, the long diagonal from top-left (476,712) goes down-right crossing the whole crop, passing through (1100,1000)?? hmm.

Actually in z19, I can see a very long blue line from top-left going all the way down-right to the BIRD dip (1384,1044)! Look: the blue line entering the bird dip from the upper-left — I attributed it to 小鸟→蛇 (head at (1084,828)). But wait, at the bird dip (2460,860)crop, the blue goes up-left to head (1710,320)crop → (1084,828) = 小鸟→蛇 ✓. That's clear.

Hmm, but is there ANOTHER blue line ending at the bird dip from up-left? Let me look... In z19, at the bird dip, I see: blue from up-left (小鸟→蛇), brown up-right (小鸟→鹰 brown-3). And separately, the long blue diagonal from the fox region... where does it end? It might end at the MOUSE dip. Both 鼠→狐 lines from heads (452,728) and (476,712)? No — two arrows mouse→fox is redundant.

OK, alternative: fox's 4th head ← 小鸟 (bird→fox)? Hmm, foxes do eat birds. The long blue diagonal from (476,712) going down-right could reach the bird dip (1384,1044). Distance: from (476,712) to (1384,1044): slope (1044-712)/(1384-476) = 332/908 ≈ 0.37 — gentle down-right. In z19, is there such a line? The 小鸟→蛇 line from (1084,828) to bird dip (1384,1044) has slope (1044-828)/(1384-1084) = 216/300 = 0.72, steeper, and it's in the right portion only. A line from (476,712) to (1384,1044) would pass (884,861)... near the snake. Hmm, I don't clearly see it.

Let me just trace the two steep blue diagonals from fox heads (452,728) and (476,712) with a dedicated crop following them down. Actually — simpler: let me check the MOUSE dip: how many blue lines leave it going up-left? In z12_mouse.png, from the mouse V (1016,1067): blue went UP (鼠→蛇), blue went up-LEFT (exiting crop left at (930,987)). Only ONE up-left blue. So only ONE 鼠→狐 line.

So fox's 4th head's line must go elsewhere. In z19, from head (476,712), the steep diagonal goes down-right past the mouse... to where? It might reach the bird. Let me trace it: crop along the line from (476,712) with slope continuing down-right. In z19, the steepest blue from (476,712) passes crop (700,400) → original (680,860)?? hmm no.

Let me do a fresh crop: (450-1500, 700-1150) and carefully identify where the steepest blue diagonal ends. Actually z19 already covers this. Let me re-view z19 at higher resolution focusing on the blue diagonals. Let me crop (450-1100, 700-1100) at 3.5x.

This crop (450-1120, 700-1120), 4x. Now very clear:

At the marmot dip (crop (650,1380) → original (612,1045)):

Hold on. The brown curve at the marmot dip: it comes from the UP-LEFT (crop (530,750) → original (582,887), continuing up-left out of crop to head (937,603)?? No — up-left from (582,887) goes to (500,800), (400,700)... that's toward the FOX, not the eagle head (937,603) which is up-RIGHT.

Hmm wait, I'm confusing myself. Let me re-read the corridor image z18: "brown curve from the marmot area: the V-dip at crop (1010,1680) → original (617,1040), going up-right with head at crop (1970,370) → original (937,603)". So in z18, the brown went UP-RIGHT from the marmot dip to head (937,603).

But in z20, the brown at the marmot dip comes from UP-LEFT. Let me look at z20 again: the brown curve enters from crop top-left (530,750)→original(582,887)... wait, actually it enters from crop LEFT at (500,760) and curves down to the dip (650,1380). Hmm, where does it come from further up? It exits the crop top at around crop (550,0)?? Let me see: in z20, the brown curve at top is at crop (1000,0)-(1100,300) → original (700,700)-(725,775)?? Hmm no.

Actually in z20 I see the brown curve: from the dip (650,1380) it goes UP-LEFT, curving, passing crop (530,750), exiting crop top at ~(1050,0)?? That doesn't look right either. Let me look at the image description again: "brown curving from upper-left down to the dip". The brown in z20: enters at crop top-left corner area (0-100, 0-100)?? no that's blue heads.

Hmm, in z20 there are clearly:

Hmm, wait: maybe it IS: from head (937,603), the curve goes down-LEFT to (712,700), (582,887), dip (612,1045). Let me check: in z18 corridor (280-980,480-1170), the brown from the marmot dip went up-right to head (937,603). The path: dip (617,1040) → up-right → head (937,603). Passing (700,900), (800,750), (900,630). In z20 (450-1120,700-1120), that path segment from (700,900) to (937,603): at crop (1000,800) → original (700,900)?? crop x = (700-450)*4 = 1000, crop y = (900-700)*4 = 800. Hmm, but I described the brown at crop (530,750) → original (582,887). That's x=582, not on the path from dip to (937,603).

I think the issue is the brown curve near the dip splits visually: the curve approaches the dip from up-left (from (582,887)) — but wait, (582,887) is up-LEFT of the dip (612,1045). And the head (937,603) is up-RIGHT of the dip. So the brown curve would be: head (937,603) → down-left → (800,750) → (700,900)?? no...

Ugh, I keep going in circles. The KEY QUESTION is just: does the brown at the marmot dip TERMINATE there (旱獭→鹰) or pass through? In z20, at the dip (650,1380), the brown curve clearly comes down and its tapered END points down at the marmot. It does NOT continue past the dip. So 旱獭→鹰 CONFIRMED, with the brown going up (whichever direction) to an eagle head.

And from z18, the brown from the marmot dip went up-right to head (937,603). Wait, in z18 I said "brown curve from the marmot area: the V-dip at crop (1010,1680), going up-right with head at crop (1970,370) → original (937,603)". But now in z20 the brown comes from up-left... These are consistent if the curve from head (937,603) descends going down-LEFT first, passing left of the dip, then curving into the dip from the up-left. Looking at z20: yes, the brown enters the crop top at crop (1050,0) → original (712,700)?? Hmm, (712,700)...

You know what, the exact path doesn't matter. What matters: 旱獭→鹰 exists (brown terminates at marmot dip). ✓

Now, the two steep BLUE diagonals in z20:

Wait, but in z20 at the mouse dip (2300,1470), I see blue lines: one going up (to 鼠→蛇 head at crop (2300,750) → original (1025,887)), one going up-left (the long diagonal to fox = 鼠→狐), and a brown going up-right (鼠→鹰).

So the fox's heads: 兔→狐, 旱獭→狐, 鼠→狐 = 3 prey... but I counted 4 blue heads at the fox! Let me recount in z18 corridor: heads at crop (140,780), (430,780), (540,720), (610,660) → original (327,740), (423,740), (460,720), (483,700). FOUR heads.

Hmm, and in z20 top-left corner, I see 2-3 blue heads (partially cut). Sources: rabbit, marmot, mouse = 3. What's the 4th?

Wait — maybe one of the "heads" I counted is actually the head of 旱獭→蛇 or a crossing. Let me look at z18 again: "blue arrowheads: crop (140,780), (430,780), (540,720), (610,660)". And also z1 earlier: "4 blue arrowheads: crop (230,575), (520,570), (620,530), (690,470) → original (327,742), (423,740), (457,727), (480,707)".

In z20 (crop 450-1120,700-1120, 4x): top-left corner shows blue heads at crop (0-200, 0-120) → original (450-500, 700-730). I can see at least 2 heads there, maybe 3, partially cut off.

Let me crop the fox's mouth area tightly to count heads: (300-550, 680-780) at 6x.

This crop (290-560, 670-790), 8x. I can clearly count FOUR blue arrowheads pointing up-left toward the fox's mouth:

So the fox has 4 prey arrows. Sources identified so far: 兔 (→head 326,740), 旱獭 (→one of them), 鼠 (→one). Need the 4th source.

The lines from these heads in the crop:

In z20, I traced: 旱獭→狐 (dips at marmot), 鼠→狐 (goes to mouse dip). That's 2 of the 3 down-right lines. The 3rd down-right line goes where?

From z19/z20: the line from head (455,725) descends steeply... In z20, two steep blue lines: one dips at marmot (612,1045), one goes to mouse dip (1025,1067). And head (480,704)'s line — the steepest, straightest — in z18 corridor it went down-right crossing everything... where does it end?

Wait, actually, maybe one goes to the BIRD: 小鸟→狐? Or to the rabbit too? No. Let me think about candidates: fox prey in such webs: 兔, 鼠, 旱獭, 小鸟. 4 arrows = 兔, 旱獭, 鼠, 小鸟. Plausible!

Let me trace the steepest line (from head (480,704)): it goes down-right. In z18, from head (483,700) [crop (610,660)], the line descended steeply down-right, crossing the 兔→鹰 brown, the 旱獭→蛇 blue, continuing down-right... exiting z18's bottom at crop (1350,2070)?? → original (730,1170)? no, z18 was (280-980,480-1170). Hmm, exiting right at crop (2100,1400) → original (980,947)? Then continuing to... the mouse (1025,1067)? or the bird (1384,1044)?

Hmm. In z20 (450-1120,700-1120), the steepest blue from top-left: I see TWO steep blues actually — one dips at marmot (612,1045), another continues to mouse dip (1025,1067). If there are THREE steep blues, the third might exit z20's right edge toward the bird. In z20, at the right edge (crop (2680,1300) → original (1120,1025)), there was a blue line exiting — I see "a blue line exiting right edge at (2680,1320)". That continues to the bird dip (1384,1044)? Possibly = 小鸟→狐!

Hmm wait, but the 小鸟→蛇 blue head was at (1084,828) with its line going down to the bird dip. A 小鸟→狐 line would ALSO end at the bird dip, coming from up-left. In z19, at the bird dip (1384,1044), I identified: blue from up-left (小鸟→蛇), brown up-right (小鸟→鹰). If there were TWO blues from up-left at the bird dip, one would be 小鸟→狐.

Let me zoom the bird dip: crop (1250-1500, 950-1100) at 6x.

This crop (1230-1530, 950-1120), 8x. The bird dip at crop (1370,780) → original (1401,1047):

Lines at the dip:

So TWO blue lines end at the bird dip: one horizontal from the left (小鸟→蛇) and one steep from up-left. The steep one from up-left — where does it come from? If from the fox head (480,704), then 小鸟→狐 ✓. That would explain the fox's 4th arrow!

Let me verify: the steep blue at the bird dip goes up-left. Following it up-left in this crop: exits crop top at (820,0) → original (1332,950). Continuing up-left toward the fox... From (1332,950) up-left to (480,704)? passes (1000,850), (700,770)... hmm, it would cross the snake area. In z19/z20, was there such a long steep blue from fox to bird? In z19, the steepest blue diagonal from fox head (476,712)...

Actually in z20, I saw at the right edge a blue exiting at crop (2680,1320) → original (1120,1030) heading down-right. From (1120,1030) to (1332,950)? Hmm, that's up-right, not down. Hmm.

Wait, actually the blue line from fox head (480,704) going to bird dip (1401,1047): it would pass through (900,860), (1100,940), (1300,1010). In z20 (450-1120,700-1120), such a line would appear at crop ((900-450)*4, (860-700)*4) = (1800,640), and exit right edge at (2680, (940-700)*4=960)... In z20, at crop (1800,640)... hmm, I don't specifically recall a blue there.

But hold on — the blue line to the bird dip might come from the MAGPIE direction instead! From the magpie (1700,380) down-left to the bird dip (1401,1047)?? That would be 小鸟→喜鹊? (magpie eats small bird?) Hmm, possible but unusual. The steep blue at the bird dip goes UP-RIGHT? No — in z22, the steep blue comes from UP-LEFT (top-left of crop, exiting at (820,0) → original (1332,950)). From (1332,950), going further up... it could curve up-right to the magpie? or up-left to the fox?

Hmm, let me trace this steep blue line upward with a crop (1100-1420, 700-1000).

This crop (1050-1450, 680-1000), 6x. I see the frog (right) and:

Now the steep blue at the bird dip came from up-left exiting z22 at (1332,950). In z23 (1050-1450,680-1000), that steep blue would appear at (1332,950) → crop (1692,1620). Do I see a steep blue line there? At crop (1692,1620)... that's below-right of the frog. The bottom-right of z23 shows blue lines going down-right: from head (1083,830) the 小鸟→蛇 line descends to the bird dip. And another blue descending steeply at crop (1692,1620)→(1332,950)...

Hmm, in z23 bottom area, I see the 小鸟→蛇 blue descending from head (200,900) down-right, exiting crop bottom-right at (2390,1900) → original (1448,997). Wait, that doesn't reach the bird dip (1401,1047)... close. OK.

And the steep blue from the bird dip going up-left exited z22 top at (1332,950). In z23, at (1332,950) → crop (1692,1620): is there a blue line? The bottom-right region of z23 shows the 小鸟→蛇 line passing (1448,997)... and what else? I see in z23's bottom portion: two blue lines descending toward the bottom-right corner, close together? One is 小鸟→蛇 (from head (1083,830)). The other...

Hmm, actually looking at z23 bottom-right: I see ONE clear blue line descending (the 小鸟→蛇). And the brown at the right edge. Hmm, wait — in z22, the steep blue at the bird dip exited the crop TOP at (820,0) → original (1332,950). But in z23 (which covers (1050-1450,680-1000)), at original (1332,950) → crop (1692,1620)... I need to look at that spot.

Actually — maybe the steep blue at the bird dip comes from the 蜘蛛 (spider)! From spider (1740,770) down-left to bird dip (1401,1047)? That would be 蜘蛛→蛇? No wait, the line ends at the bird dip (blunt end at bird), so the bird is the PREY. If it comes from the spider's direction... hmm, but the head would be at the predator. The line: blunt end at bird dip (1401,1047), going up... to a head at some predator. In z22, it went UP from the bird dip (exiting top at (1332,950)). So the predator is ABOVE: eagle? But it's BLUE not brown. Magpie? 小鸟→喜鹊?!

Hmm wait, in z22 the steep blue exited top at (1332,950) heading up. Where's its head? Let me look at z23 at (1332,950) → crop (1692,1620) and trace up. Actually, in z23, I notice at the top: blue head (1138,745) with its steep line going up-right (喜鹊→蛇). Hmm.

Let me re-crop to follow the steep blue from the bird dip upward: region (1250-1500, 550-1000).

This crop (1250-1520, 550-1000), 8x. I see the frog (right-center). Blue lines:

Brown lines:

Wait — earlier in z19 I thought this brown continued down to the bird dip. But here at 8x zoom, the brown clearly ENDS at (1325,768), right at the frog's top-left. It does NOT continue to the bird dip. So brown-3 = 青蛙→鹰 ✓.

Now, the steep blue at the bird dip (from z22, exiting top at (1332,950)): in z24, do I see it? At the bottom-left, the 小鸟→蛇 blue goes down-right. Hmm, actually wait — in z22, I saw at the bird dip: blue from left (horizontal, 小鸟→蛇), blue from up-left (steep), brown up-right. But maybe I misread z22: perhaps the "steep blue from up-left" is actually the SAME 小鸟→蛇 line (which comes from head (1083,830) at up-left) and the "horizontal blue from left" is a DIFFERENT line — the 蜘蛛→蛇 line passing at y~772? No, z22 crop was y 950-1120, the 蜘蛛→蛇 line at y~772 is above it.

Hmm wait, in z22, at the dip (1401,1047): one blue came from the LEFT horizontally (at y~1047), another blue descended from up-left. The horizontal one from the left at y~1047 — where does IT come from?

Oh! Maybe the horizontal blue from the left at the bird dip is 小鸟→蛇 (from head (1083,830), sweeping down and approaching the dip from the left horizontally), and the steep blue from up-left is ANOTHER arrow: 小鸟→狐 (from fox head (480,704))!

In z24 (1250-1520,550-1000), the steep blue would pass through around (1332,950) → crop (656,3200)... at the bottom of z24. And continue up-left out of the crop. In z24 bottom-left, I see the 小鸟→蛇 blue at crop (0-500, 2700-3600) going down-right. Is there ANOTHER blue line parallel/adjacent? Looking at z24 bottom-left: just one blue line visible descending.

Hmm. But wait — in z24, at crop (600,1750) the brown ends at the frog. In z19, I thought brown-3 continued to the bird dip. Since brown-3 actually ends at the frog, what brown continues to the bird dip then? In z22, brown went UP-RIGHT from the bird dip. That brown = brown-4 (the x~1493-1506 line)? But brown-4 in z24 is at x~1493-1506, and the bird dip is at (1401,1047). In z22 (1230-1530,950-1120), the brown at the bird dip went up-right exiting at (1530, ~950)?? → the brown exited z22 top-right at crop (1900,0) → original (1467,950). And brown-4 in z24 at x~1493-1506 spans y 550-1000. So from the bird dip (1401,1047), the brown goes up-right to (1467,950), then continues up at x~1493-1506 (z24) to... head (1167,350)? So 小鸟→鹰 = brown-4, head (1167,350). ✓

Then what is the steep blue at the bird dip going up-left (exiting z22 top at (1332,950))? Hmm, wait — maybe I misjudged z22. Let me look at z22 again: at the dip (1370,780)crop:

In z24 (1250-1520,550-1000), the steep blue from (1332,950) going up-left: it would exit z24's left edge at around y~850-900 → crop (0, 2400-2800). In z24, the 小鸟→蛇 blue at bottom-left exits at crop (0, ~2750) → original (1250, ~894)?? Hmm, wait: 小鸟→蛇 from head (1083,830) descends to bird dip (1401,1047): at x=1250, y = 830 + (1047-830)(1250-1083)/(1401-1083) = 830+217167/318 = 830+114 = 944. So 小鸟→蛇 exits z24 left edge at (1250,944) → crop (0,3152). And the steep blue (if from fox) at x=1250: from fox head (480,704) to bird dip (1401,1047): y = 704 + (1047-704)(1250-480)/(1401-480) = 704+343770/921 = 704+287 = 991. So it would exit z24 left edge at (1250,991) → crop (0,3528).

In z24 bottom-left, I see ONE blue line descending, exiting around crop (0,3300-3600)?? The two lines would be ~376px apart in crop — I might have seen them as one or the region is ambiguous. Hmm.

OK, this is taking very long. Let me step back and think about which interpretation makes a consistent web.

Actually — wait. Let me reconsider the steep blue at the bird dip. In z22, the steep blue exits the crop top at crop (820,0) → original (1332,950). From (1332,950), going up — in z24 at (1332,950) → crop (656,3200). Looking at z24 at that location... the brown vertical at x~1325 ends at the frog (1325,768). Below the frog, is there a blue line at x~1332 going down to the bird dip? In z24, at crop (656, 1750-3600): I see... the frog is at crop (620-1500, 1550-2350). Below the frog at crop (656, 2500-3600)... hmm, I don't see a clear steep blue there in z24.

Alternatively, the steep blue at the bird dip comes from the SPIDER (蜘蛛→蛇? no...). Or from the MAGPIE (小鸟→喜鹊): from magpie (1700,380) down to bird dip (1401,1047)? At (1332,950)... the line from magpie (1700,380) to dip (1401,1047): at y=950, x = 1700 + (1401-1700)(950-380)/(1047-380) = 1700 - 299570/667 = 1700-255 = 1445. So at y=950, x~1445, not 1332. Doesn't match.

OK you know what, let me just re-examine z22 very carefully one more time. Actually, let me re-crop the bird dip even tighter with less enhancement to avoid artifacts.

This crop (1080-1460, 800-1080), 7x, ORIGINAL image (no enhancement). Now clear:

Wait, the horizontal blue at the bottom of this crop: it extends from crop left edge (0,1610) → original (1080,1030), curving to the V-point (1354,1041). So it comes from the left at y~1030. Following it left beyond the crop: toward... the mouse dip (1025,1067)? That's at y~1067, close-ish. Hmm, or from further left — the fox?! A fox→bird line (小鸟→狐) would come from far left.

Hmm, wait — actually, could this horizontal blue be 鼠→蛇? No, 鼠→蛇 head is at (1024,884).

Hold on. Let me reconsider: maybe the horizontal blue from the left ending at the bird V-point is the fox's 4th arrow: 小鸟→狐! From fox head (480,704), going down-right across the whole diagram to the bird dip (1354,1041). Let me check its path: at x=1080, y~1030. Line from (480,704) to (1354,1041): at x=1080, y = 704 + (1041-704)(1080-480)/(1354-480) = 704+337600/874 = 704+231 = 935. But the observed blue at x=1080 is at y~1030, not 935. So it's NOT a straight line from the fox. It's more horizontal. Hmm.

Actually, from the V-point (1354,1041), the blue curves left and slightly up to y~1030 at x=1080. If it continues left curving... it could reach the mouse dip (1025,1067)? From (1025,1067) to (1354,1041) — nearly horizontal! Yes! At x=1080, this line would be at y~1060, but observed y~1030. Hmm, 30px off. Close but not exact.

Alternatively — maybe this horizontal blue is actually the bottom edge of the 蜘蛛→蛇 line?? No, that's at y~772.

OK wait, I think I need to look at the whole picture again. In the earlier z19 view (400-1500, 700-1210), I noted: "3. Bird V-dip at crop (2460,860) → original (1384,1044): BLUE line going up-left from dip → head at crop (1710,320) → original (1084,828) = 小鸟→蛇 ✓; BROWN line going up-right from dip → 小鸟→鹰 ✓; Also a BLUE line passing horizontally above (the 蜘蛛→蛇 line at y~770-790)".

Hmm, so in z19, at the bird dip I saw blue up-left and brown up-right. In z22 (1230-1530,950-1120, 8x), at the dip: blue from left (horizontal), blue from up-left (steep), brown up-right. In z25 (1080-1460,800-1080, 7x): blue from up-left (diagonal, 小鸟→蛇) and blue from left (horizontal) converging at the V-point (1354,1041).

So consistent: TWO blue lines converge at the bird V-point: one steep diagonal from (1089,829) = 小鸟→蛇, one horizontal from the left = ???

The horizontal one from the left at y~1030-1041: Let me trace it further left. In z19 (400-1500,700-1210, 2.5x), this horizontal blue at y~1035 would appear at crop y~(1035-700)*2.5=838. In z19, at the bottom area, y~838, I see... the mouse dip at (1016,1068) and lines. Hmm.

Actually — OH WAIT. Maybe the horizontal blue into the bird V-point is the 蜘蛛→蛇 line? No. Or... could it be 小鸟→蛇 #2? No.

Let me think: predators of the small bird: 蛇 (head (1089,829)), 鹰 (brown), and possibly 狐. If the fox's 4th arrow is 小鸟→狐, the line would come from the far left. The observed horizontal blue comes from the left. Let me trace it leftward with a crop (600-1400, 950-1100).

This crop (600-1400, 980-1120), 4x. I see:

So this long, gently-descending blue line connects... from upper-left (912,980) and beyond up-left, to the bird V-point (1400,1042). Following it up-left: at crop (1250,0) it's at original (912,980); continuing up-left, where does it originate? Let me extend: the line direction from (912,980) to (1400,1042): slope = 62/488 = 0.127 (very gentle). Extrapolating backward: at x=480 (fox head), y = 980 - 0.127*(912-480) = 980-55 = 925. Hmm, fox heads are at y~704-744. Not matching a straight line from fox. But the line curves. At x=600, y = 980-0.127*312 = 940. At x=700, y~927.

Hmm, where does this line come from? It might originate at the MOUSE! Wait — the mouse dip is at (1015,1067), and the line passes at (912,980) and (1015, ~1033)... does it touch the mouse dip? At x=1015, the line y = 980+0.127*(1015-912) = 993. The mouse dip is at (1015,1067). So the line passes ~74px ABOVE the mouse dip. Doesn't touch.

Hmm! So this long blue line passes above the mouse and ends at the bird V-point. Its left end: extrapolating, it curves up-left. Where does it START? Let me trace further left with crop (450-950, 850-1000).

Actually wait — could this be the 蜘蛛→蛇 line?? No, that's at y~772. Could it be 小鸟→狐? From fox head (480,704)? Extrapolating the gentle slope back: at x=480, y~925. But fox heads at y~704-744. The line would need to curve sharply up at the left end. Possible! Lines in this diagram do curve (e.g., 旱獭→狐 curves). Let me trace it left.

This crop (440-980, 840-1010), 6x. I see the long blue line descending from upper-left to lower-right, crossing other lines. At crop (1490,270) → original (688,885), it crosses a blue line going down (旱獭→狐?). At crop (900,20) → original (590,843), it crosses the brown 旱獭→鹰.

The long blue line at the left edge: crop (810,0) → original (575,840) entering from the top. So it comes from above-left at (575,840). Continuing up: toward the fox head (480,704)! From (575,840) up-left to (480,704): direction (-95,-136). Yes! So this long blue line = 小鸟→狐!! From the bird V-point (1400,1042), traversing left across the whole diagram, curving up at the left end to the fox's head (480,704).

So the fox's 4th arrow = 小鸟→狐 ✓. Fox eats: 兔, 旱獭, 鼠, 小鸟 (4 prey).

Wait, hold on. Let me double-check the direction of this arrow. The arrowhead is at the FOX end (480,704) — one of the 4 blue heads at the fox's mouth. The blunt end is at the bird V-point. So yes: 小鸟→狐. ✓

Hmm, but wait — actually let me reconsider. The blue line I traced goes from the bird V-point leftward and up to (575,840), continuing up-left. But could it instead go up-RIGHT from (575,840)? No — at (575,840) it's entering the top of the crop going up-left. To the fox. OK: 小鸟→狐.

Hmm, actually wait. Let me reconsider once more. In z27, the long blue line enters at top at crop (810,0) → original (575,840). In z20 (450-1120,700-1120), this line would be at crop ((575-450)*4, (840-700)4) = (500,560). In z20 at (500,560)... there were steep blue diagonals from the fox heads. The steepest one from head (480,704): passes (575,840)? From (480,704) direction to (575,840): slope 136/95 = 1.43. Continuing: at x=700, y = 704+1.43220 = 1019?? Hmm, that overshoots. But the line curves (becomes more horizontal to the right). OK plausible: from head (480,704), steep at first, then flattening, passing (688,885), (912,980), ending at bird (1400,1042). Yes: 小鸟→狐. ✓

GREAT. So now the fox's 4 prey: 兔、旱獭、鼠、小鸟.

Now let me also double check the snake's prey list. Snake's blue heads:

Wait, 喜鹊→蛇? The snake eats the magpie? Let me re-verify that one. In z10 (1100-1800,380-780), the blue line from head (1122,742) went up-right with blunt end at (1692,425) near the magpie's feet/branch. So yes: 喜鹊→蛇. Hmm, snakes eating birds is ecologically fine.

And 蜘蛛→蛇: the blue from head (1122,772) goes right at y~772 to the spider (1740,770)? Let me verify its right end. In z6, it passed below the frog exiting at (1550,782). Beyond: the spider at (1700-1807, 712-855). A line at y~782 would hit the spider's left side. Plausible: 蜘蛛→蛇. Let me verify with a crop (1450-1800, 730-830) quickly.

Also verify the eagle's remaining brown arrows:

So eagle has 8 prey: 狐、兔、旱獭、鼠、蛇、青蛙、小鸟、喜鹊.

Wait — but does the eagle really eat the FOX? That's the odd one. Let me re-examine z5/z18. The brown blunt end at (496,604) right next to the fox's nose... Actually, hmm, you know, looking at z18 again: the topmost brown curve with head at (717,500), its blunt end at (497,600) — right at the fox's open mouth. This really looks like 狐→鹰.

Hmm, but actually — wait. Could the blunt end actually be at the RABBIT, with the curve passing behind the fox? No — the blunt end is clearly at (497,600), fox's mouth level.

OK whatever the ecological plausibility, the diagram shows: 狐→鹰. Actually, hold on, let me reconsider — maybe it's 兔→狐 and I'm misreading color? No, the 4 fox blue heads are separate. The brown curve from the fox's mouth to the eagle is distinct.

Hmm, one more consideration: maybe the arrow at the fox's mouth is actually pointing FROM the eagle TO the fox?? Arrowhead at (717,500) — which way does it point? In z5, the arrowhead at crop (1600,60) pointed up-right (toward eagle). So fox→eagle. OK.

Now the remaining checks:

Hmm wait, but let me double-check the 蜘蛛→蛇 line doesn't actually start at the frog. And check whether 青蛙→蛇 exists as a separate line. Let me crop (1100-1800, 740-870) wide.

Also need to double check: 昆虫→喜鹊 (the big loop) — its blunt end at the insect. In z9, the blue loop went down off the right edge at (1920,675) and came back at (1920,1037), continuing down to the insect (1740,1160)? The blunt end near the insect. Let me verify with a crop of the bottom-right (1650-1920, 1000-1250).

Let me do these final verification crops.

z28 (1100-1800, 730-880, 5x):

Wait, hold on — the second blue head (1122,768): its line passes above the frog and ends at the spider. So 蜘蛛→蛇. But hmm, could it be 青蛙→蛇 instead? The line passes very close above the frog's head but its blunt end is clearly at the spider's left leg (1684,784). So 蜘蛛→蛇. ✓

z29 (1600-1920, 1000-1280, 6x):

So the insect is eaten by: 蜘蛛、青蛙、喜鹊 (3 predators). NOT by the small bird.

Now let me compile the complete food web:

Producers: 草

Arrows (prey → predator):

Let me count food chains (paths from 草 to top predators with no further predators):

Top predators (no outgoing arrows): 鹰 only? Let me check: 狐→鹰 exists, so 狐 is not top. 蛇→鹰 exists. 喜鹊→蛇、喜鹊→鹰 exist. 蜘蛛→青蛙、蛇、喜鹊. 青蛙→鹰. So the ONLY top predator is 鹰.

All food chains end at 鹰. Count paths from 草 to 鹰:

Prey of 鹰: 狐、兔、旱獭、鼠、蛇、青蛙、小鸟、喜鹊 (8 direct).

For each, count sub-paths from 草:

A. 草→兔→鹰 (1) B. 草→旱獭→鹰 (1) C. 草→鼠→鹰 (1) D. 草→小鸟→鹰 (1) E. 草→食草昆虫→青蛙→鹰 (1) F. via 狐→鹰: prey of 狐: 兔、旱獭、鼠、小鸟 F1. 草→兔→狐→鹰 F2. 草→旱獭→狐→鹰 F3. 草→鼠→狐→鹰 F4. 草→小鸟→狐→鹰 (4) G. via 蛇→鹰: prey of 蛇: 旱獭、鼠、小鸟、蜘蛛、喜鹊 G1. 草→旱獭→蛇→鹰 G2. 草→鼠→蛇→鹰 G3. 草→小鸟→蛇→鹰 G4. 草→食草昆虫→蜘蛛→蛇→鹰 G5. via 喜鹊→蛇→鹰: prey of 喜鹊: 蜘蛛、食草昆虫 G5a. 草→食草昆虫→蜘蛛→喜鹊→蛇→鹰 G5b. 草→食草昆虫→喜鹊→蛇→鹰 (5) H. via 喜鹊→鹰: prey of 喜鹊: 蜘蛛、食草昆虫 H1. 草→食草昆虫→蜘蛛→喜鹊→鹰 H2. 草→食草昆虫→喜鹊→鹰 (2)

Total = 1+1+1+1+1 + 4 + 5 + 2 = 16

Let me list them all out:

Wait, that's 17! Let me recount: A(1) B(1) C(1) D(1) E(1) = 5; F = 4 (total 9); G = 5 (total 14); H = 2 (total 16). Hmm, 5+4+5+2 = 16. But my numbered list shows 17. Let me recount the numbered list: 1,2,3,4,5 (5 items = A,B,C,D,E ✓); 6,7,8,9 (4 items = F1-F4 ✓); 10,11,12,13,14,15 (6 items!) — that's G1,G2,G3,G4,G5a,G5b = 6, not 5! I miscounted G: G1,G2,G3,G4,G5a,G5b = 6 items. So G = 6. Total = 5+4+6+2 = 17.

Wait: G prey of 蛇: 旱獭、鼠、小鸟、蜘蛛、喜鹊 = 5 prey, but 喜鹊 contributes 2 sub-paths (喜鹊 eats 蜘蛛 and 昆虫), and 蜘蛛 contributes 1 (草→昆虫→蜘蛛→蛇→鹰). So: G1. 草→旱獭→蛇→鹰 G2. 草→鼠→蛇→鹰 G3. 草→小鸟→蛇→鹰 G4. 草→食草昆虫→蜘蛛→蛇→鹰 G5a. 草→食草昆虫→蜘蛛→喜鹊→蛇→鹰 G5b. 草→食草昆虫→喜鹊→蛇→鹰 = 6 chains.

H via 喜鹊→鹰: H1. 草→食草昆虫→蜘蛛→喜鹊→鹰 H2. 草→食草昆虫→喜鹊→鹰 = 2 chains.

Total = 5 + 4 + 6 + 2 = 17.

Hmm wait, but G4 (草→食草昆虫→蜘蛛→蛇→鹰) and G5a (草→食草昆虫→蜘蛛→喜鹊→蛇→鹰) both valid since 蜘蛛→蛇 AND 蜘蛛→喜鹊→蛇. Yes.

Let me double check prey lists:

Wait — does the small bird eat only grass? I found 草→小鸟 (blue head at bird's feet (1387,1194)) and NO 昆虫→小鸟. Hmm, but let me double-check there's no green arrow 昆虫→小鸟. In z17, between the moth and the bird, I saw no connecting arrow. Also in z29, above the moth only green (to frog/spider) and blue (to magpie) lines. Let me be thorough and check the region between insect (1700,1160) and bird (1440,1130) once more, plus whether the bird has any other incoming arrows besides 草→小鸟.

Actually wait — I should double-check the 草→小鸟 arrow really points to the bird and not something else. In z17: blue head at (1387,1194) pointing up-right at the bird's feet. Yes, 草→小鸟.

Also, does 兔 have any other predators? 狐、鹰. Does anything eat 兔 besides those? No other arrows end at rabbit.

Also check: 旱獭→蛇 confirmed (head (847,747) from marmot dip). And 旱獭→狐, 旱獭→鹰. So marmot has 3 predators. ✓

Now, the count: 17 food chains. Hmm, but wait — I should double-check the 狐→鹰 arrow once more, since it's ecologically odd. If 狐→鹰 were NOT actually present (e.g., I misread and that brown arrow's blunt end is actually at the rabbit or is part of another arrow), the count would drop by 4 (F1-F4) to 13. Let me re-verify z5/z18 once more.

In z5 (400-780,480-720, 5x): the brown curve with head at (720,492), blunt end at (496,604). The fox's nose at (474,638). The blunt end is at (496,604) — 22px right of the nose, 34px above. Hmm, it's right next to the fox's face/mouth. It doesn't touch any other animal. The rabbit is at (320,1040) — far away. So the blunt end is associated with the fox. 狐→鹰.

In z18 (280-980,480-1170, 3x): the topmost brown curve: head at (717,500), sweeping left-down, blunt end at (497,600) beside the fox's mouth. Yes.

So 狐→鹰 is in the diagram. OK.

Hmm, wait, actually — one more sanity check. Let me reconsider whether the blunt end at (497,600) might actually be an arrowHEAD pointing at the fox (i.e., 鹰→狐, eagle eats fox... no wait, that would still be fox as prey). The arrowhead is at (717,500) near the eagle. The other end at (497,600) is blunt/tapered. So the fox is the prey, eagle the predator. 狐→鹰. Either way, for counting food chains, it's 狐→鹰.

Hmm, but hold on — is it possible that this brown curve is actually the 兔→狐 blue arrow misidentified? No, it's clearly brown/orange in z18 and z5.

OK so total 17 food chains. But wait, let me reconsider the snake eating 喜鹊 (magpie). That's also a bit odd. Let me re-verify z10. In z10 (1100-1800,380-780,4x): blue head at (1122,742) pointing left-down at the snake's head; the blue line goes up-right, blunt end at (1692,425) right below the magpie's feet on the branch. So 喜鹊→蛇. Hmm. Ecologically, snakes can eat birds. OK.

But wait — could the blunt end at (1692,425) actually be pointing at the magpie's prey or something else? The magpie stands on a branch at (1662-1800,380-492). The blunt end at (1692,425) is right below the magpie. So 喜鹊→蛇. ✓

And 蜘蛛→喜鹊 (blue head (1752,542), blunt at spider top (1757,670)) ✓ z9.

So 17 food chains total.

Hmm, wait. Let me reconsider 喜鹊's predators and prey once more:

OK.

And 青蛙: prey 昆虫、蜘蛛; predator 鹰 only. ✓ 蜘蛛: prey 昆虫; predators 青蛙、蛇、喜鹊. ✓

Now recount carefully with a systematic enumeration. Adjacency (prey→predator): 草 → 兔, 旱獭, 鼠, 小鸟, 昆虫 兔 → 狐, 鹰 旱獭 → 狐, 蛇, 鹰 鼠 → 狐, 蛇, 鹰 小鸟 → 狐, 蛇, 鹰 昆虫 → 蜘蛛, 青蛙, 喜鹊 蜘蛛 → 青蛙, 蛇, 喜鹊 青蛙 → 鹰 喜鹊 → 蛇, 鹰 蛇 → 鹰 狐 → 鹰

Number of chains from 草 to 鹰 (only top predator):

DFS count: count(鹰) = 1 (terminal) count(狐) = count(鹰) = 1 count(蛇) = count(鹰) = 1 count(青蛙) = count(鹰) = 1 count(喜鹊) = count(蛇) + count(鹰) = 1+1 = 2 count(蜘蛛) = count(青蛙) + count(蛇) + count(喜鹊) = 1+1+2 = 4 count(昆虫) = count(蜘蛛) + count(青蛙) + count(喜鹊) = 4+1+2 = 7 count(兔) = count(狐) + count(鹰) = 1+1 = 2 count(旱獭) = count(狐)+count(蛇)+count(鹰) = 3 count(鼠) = 3 count(小鸟) = 3 count(草) = count(兔)+count(旱獭)+count(鼠)+count(小鸟)+count(昆虫) = 2+3+3+3+7 = 18

Hmm, 18?! Let me recheck.

count(兔) = paths from 兔 to 鹰: 兔→鹰, 兔→狐→鹰 = 2 ✓ count(旱獭): 旱獭→鹰, 旱獭→狐→鹰, 旱獭→蛇→鹰 = 3 ✓ count(鼠): 鼠→鹰, 鼠→狐→鹰, 鼠→蛇→鹰 = 3 ✓ count(小鸟): 小鸟→鹰, 小鸟→狐→鹰, 小鸟→蛇→鹰 = 3 ✓ count(昆虫): 昆虫→蜘蛛→{青蛙→鹰, 蛇→鹰, 喜鹊→{蛇→鹰, 鹰}}, 昆虫→青蛙→鹰, 昆虫→喜鹊→{蛇→鹰, 鹰} = 昆虫→蜘蛛→青蛙→鹰

Earlier manual enumeration gave 17 — I missed one. Let me find which: earlier I had: A. 草→兔→鹰 ✓ (兔 contributes 2: this + 草→兔→狐→鹰) F1. 草→兔→狐→鹰 ✓ — so 兔's 2 chains are both there. In my first enumeration, under "A. 草→兔→鹰 (1)" I counted only 1 for rabbit-direct, and F1 for rabbit-fox. That's 2. ✓ B. 草→旱獭→鹰, F2. 草→旱獭→狐→鹰, G1. 草→旱獭→蛇→鹰 = 3 ✓ C. 草→鼠→鹰, F3. 草→鼠→狐→鹰, G2. 草→鼠→蛇→鹰 = 3 ✓ D. 草→小鸟→鹰, F4. 草→小鸟→狐→鹰, G3. 草→小鸟→蛇→鹰 = 3 ✓ E. 草→食草昆虫→青蛙→鹰 G4. 草→食草昆虫→蜘蛛→蛇→鹰 G5a. 草→食草昆虫→蜘蛛→喜鹊→蛇→鹰 G5b. 草→食草昆虫→喜鹊→蛇→鹰 H1. 草→食草昆虫→蜘蛛→喜鹊→鹰 H2. 草→食草昆虫→喜鹊→鹰 Missing: 草→食草昆虫→蜘蛛→青蛙→鹰 !! (昆虫→蜘蛛→青蛙, since 蜘蛛→青蛙 exists!)

Yes! I forgot 草→食草昆虫→蜘蛛→青蛙→鹰. So total = 17+1 = 18.

Let me verify count(蜘蛛)=4: 蜘蛛→青蛙→鹰, 蜘蛛→蛇→鹰, 蜘蛛→喜鹊→蛇→鹰, 蜘蛛→喜鹊→鹰 = 4 ✓. So 昆虫 chains: via 蜘蛛 (4): 昆虫→蜘蛛→青蛙→鹰, 昆虫→蜘蛛→蛇→鹰, 昆虫→蜘蛛→喜鹊→蛇→鹰, 昆虫→蜘蛛→喜鹊→鹰; via 青蛙 (1): 昆虫→青蛙→鹰; via 喜鹊 (2): 昆虫→喜鹊→蛇→鹰, 昆虫→喜鹊→鹰. Total 7 ✓.

Grand total: 2+3+3+3+7 = 18 food chains.

Complete list of 18:

18 food chains.

Hmm, but wait — I should double-check some of the trickier arrows once more, because the count is sensitive:

One more check — did I miss any arrow? Let me think about what each animal eats:

Total arrows = 5 + 1 + 2 + 2 + 5 + 4 + 8 = 27 arrows. Matches my earlier count of 27. ✓

So the number of food chains = 18.

Hmm, wait. But actually, let me reconsider whether the small bird eats 草 or 昆虫. Looking at the image again: the bird looks like a sparrow. The arrow 草→小鸟 exists. In many textbook versions, the bird eats the insect (食虫鸟). Here the bird clearly has 草→小鸟 and no 昆虫→小鸟. OK, as drawn.

Also, should I double check 草→兔: in bot.png, the blue arrowhead at ~(300,1235) pointing to the rabbit. ✓

Let me also double-check that I haven't missed any predator of the rabbit (e.g., 蛇? does 蛇 eat 兔?). Snake's 5 heads accounted for: 旱獭、鼠、小鸟、蜘蛛、喜鹊. No 兔→蛇. ✓

And does anything eat the fox besides the eagle? No. ✓ Does anything eat the eagle? No. ✓

So: 18 food chains.

Hmm, hold on. Let me reconsider the 喜鹊→蛇 arrow once more, because if the magpie is NOT eaten by the snake, the count changes: count(喜鹊) would be 1 (only 喜鹊→鹰), then count(蜘蛛) = 1+1+1 = 3, count(昆虫) = 3+1+1 = 5, count(蛇)=1, and total = count(兔)2+count(旱獭)3+count(鼠)3+count(小鸟)3+count(昆虫)5 = 16. And if 狐→鹰 also removed: 13. And if 喜鹊→蛇 kept but 狐→鹰 removed: 12.

So the answer is sensitive to these. Let me be extra careful with 喜鹊→蛇 and 狐→鹰.

喜鹊→蛇: In z10, the blue line from snake head (1122,742) goes up-right, crossing brown lines, ending blunt at (1692,425) right below the magpie's feet. Let me re-verify with fresh eyes — crop (1100-1750, 400-780) original.

狐→鹰: z5 showed it clearly. But let me reconsider: the blunt end at (496,604) — is it possible this is actually the START of the 兔→鹰 curve and the rabbit connection? No — the 兔→鹰 curve is separate (long diagonal from (280,903)). The (496,604) blunt end is right at the fox's mouth. Definitely 狐→鹰.

Actually — hmm, wait. One thing I should double-check: is the brown curve from the fox's mouth really ending at (496,604), or does it continue down-left to the rabbit? In z5, the blunt end at crop (480,620) → original (496,604) clearly terminates (tapered end). It does NOT continue to the rabbit. And in z18, same. So 狐→鹰. ✓

Let me just re-verify 喜鹊→蛇 with a fresh crop to be safe.

This crop (1100-1750, 400-780), 4x. I see:

So 喜鹊→蛇 confirmed.

FINAL FOOD WEB (27 arrows): 草 → 兔、旱獭、鼠、小鸟、食草昆虫 兔 → 狐、鹰 旱獭 → 狐、蛇、鹰 鼠 → 狐、蛇、鹰 小鸟 → 狐、蛇、鹰 食草昆虫 → 蜘蛛、青蛙、喜鹊 蜘蛛 → 青蛙、蛇、喜鹊 青蛙 → 鹰 喜鹊 → 蛇、鹰 蛇 → 鹰 狐 → 鹰

Food chain count = 18.

Let me write a quick script to double-check the count programmatically.

The programmatic enumeration confirms 18 food chains.

Now let me present the answer clearly to the user. I should:

The user is asking a simple counting question. I should be concise but complete. A table or list format works. The user communicates in Chinese, so respond in Chinese with full-width punctuation.

I should present:

Keep it organized but not overly long.