Domain: Natural Science — Morphology
Target concept: Sexual dimorphism in mandarin ducks: Male mandarin ducks have vibrant plumage (red beak, green head, yellow breast), while females are gray-brown with gray beaks, which is a typical characteristic of the East Asian wetland population.

Video generation prompt: Show two columns: the left column displays a female mandarin duck from an East Asian wetland population, and the right column displays a male mandarin duck from the same population. The images highlight the differences in feather coloration and morphological features between the two individuals.

Evaluation guide:
(i) Target concept: Visual demonstration of sexual dimorphism in breeding-plumage mandarin ducks (Aix galericulata) as a population-level contrast between the sexes.
Minimum mechanism: The video depicts adult mandarin ducks in breeding (nuptial) plumage, when the sex-linked plumage contrast between the two columns is at its most pronounced; adult males undergo a seasonal eclipse plumage in which they temporarily resemble females, so the male-typical features shown here (green head, red beak, yellow breast) reflect the breeding-season condition rather than a year-round, environmentally invariant state. Within this breeding-season depiction, the two columns must stay non-overlapping and internally consistent: no intermediate coloration, no age-related gradient, and no mixing of male and female traits on the same individual.
(ii)Storyline: Frame opens to a static wetland-background scene divided by an invisible vertical midline; the left column reveals a stationary female mandarin duck in her typical cryptic plumage (gray-brown body, gray beak, no ornamentation); simultaneously, the right column reveals a stationary male mandarin duck in breeding (nuptial) plumage (green head, red beak, yellow breast, crest, eye-crescent); both individuals maintain identical posture, scale, and lighting response throughout; no motion beyond natural micro-stillness (e.g., gentle breathing); viewer perspective is frontal, eye-level, fixed: no camera movement, zoom, or tilt; visibility is unobstructed and full-body, with no occlusion.

Manual:
Experimental Procedure
1. Display two mandarin ducks simultaneously in a single static frame: left column = female, right column = male.
2. Maintain a fixed viewpoint and side-by-side spatial alignment for the full duration.
Observation of Experimental Phenomena
Left column: an individual with gray-brown body plumage, a gray beak, no green head, and no yellow breast.
Right column: an individual with an iridescent green head, a red beak, a bright yellow breast, a white eye-crescent, and an upright crest.
Summary of Experimental Principles
Sexual dimorphism in East Asian mandarin ducks during the breeding season: males display vivid nuptial plumage for mating display, while females retain cryptic gray-brown plumage for nesting camouflage year-round. Outside the breeding season, adult males molt into a female-like eclipse plumage, so the vivid male coloration shown here reflects the breeding-season condition rather than a permanent, unchanging state.

Prompt Grounding rubric:
level_1: No mandarin ducks appear in the video; or only one duck appears without a two-column layout; or the birds shown are not mandarin ducks (e.g., mallards, swans, or a non-avian object stands in for one column); or the video never establishes a side-by-side, two-column arrangement.
level_2: Two birds appear side by side, but at least one is not recognizable as a mandarin duck (e.g., the wrong bill shape, a crest where that sex should not have one, or mismatched body proportions); or the columnar layout exists but the two ducks are stacked vertically, shown in separate cuts, or otherwise do not share the same frame and viewpoint at the same time.
level_3: Two mandarin ducks appear in a left-right columnar arrangement within a single static frame; both are recognizably ducks with the correct compact body, short neck, and broad bill; no other animals or people are present in the shot; no column labels or text overlays are required at this level.
level_4: Two mandarin ducks appear in a left-right columnar arrangement within a single static frame; both show correct mandarin duck anatomy (rounded head, short bill, upright resting posture, wings folded rather than spread unnaturally); there is no morphological distortion (fused bodies, missing limbs, mismatched scale between the two columns); the frame holds as one continuous shot for the full clip with no scene cuts.
level_5: Two mandarin ducks appear in a fixed left-right columnar arrangement within a single unbroken shot; both hold a stable, front-facing or only slightly angled (roughly 30 degrees or less) posture for the whole clip; there is no motion blur, cropping, or sudden reframing; the left column contains exactly one duck and the right column contains exactly one duck, with no duplicated or mirrored copies of either bird.

Scientific and Causal Correctness rubric:
level_1: Both ducks show the same plumage coloration (e.g., both green-headed, or both gray-brown); or both have red beaks, or both have yellow breasts; or the duck in the female (left) column shows male-typical features (green head, red beak, ornamental crest), or vice versa.
level_2: One duck shows a single correct sex-typical trait (e.g., the left duck has gray-brown body plumage) but a contradictory trait elsewhere on the same bird (e.g., that same left duck also has a red beak or yellow breast); or the right duck has a green head but a gray, not red, beak, and no yellow breast.
level_3: The left duck shows the three core female-typical traits together: gray-brown body plumage, a gray beak, and no green head or yellow breast; the right duck shows the three core male-typical traits together: a green head, a red beak, and a yellow breast; neither duck shows a trait borrowed from the opposite sex.
level_4: Everything described for score 3 is present, and in addition each duck shows secondary sex-typical detail consistent with breeding-season mandarin ducks: the left (female) duck shows a pale eye-ring and mottled, unornamented flanks with no crest; the right (male) duck shows a distinct white crescent behind the eye and a raised crest, on top of its green head, red beak, and yellow breast.
level_5: Everything described for score 4 is present, and in addition the plumage contrast is complete and mutually exclusive: the left duck shows only female-typical features (gray-brown body, gray beak, pale eye-ring, no crest, no green or yellow anywhere) and the right duck shows only male-typical breeding features (iridescent green head, red beak, bright yellow breast, white eye-crescent, crest), with no trait from one column appearing on the other: e.g., no yellow tint on the left duck, no gray-brown patch on the right duck's head or breast.

Spatiotemporal Consistency rubric:
level_1: One or both ducks jump to a different position between frames with no motion shown; or one of the two ducks is missing from its column for a stretch of the video and then is back in frame with no visible entrance; or the lighting suddenly changes (e.g., full daylight to near darkness) with no visible cause; or the background changes abruptly between unrelated settings (e.g., a reed bed, then a concrete wall, then a forest); or a duck's body visibly comes apart (e.g., its head separates from its body).
level_2: The ducks stay in their columns but show heavy visual distortion: stretching, warping, or melting of the body; or persistent flicker across the frame; or the two columns cast shadows in visibly opposite directions under what should be the same light source; or a sudden brightness or contrast shift affects only one column.
level_3: Both ducks stay continuously visible in their own column for the whole clip; the background is the same static scene behind both columns; the lighting direction and brightness look the same on both ducks; neither duck is clipped at the frame edge, occluded, or shows visible tearing or ghosting between frames.
level_4: Everything described for score 3 is present, and in addition the background is continuous across the vertical midline with no visible seam or mismatch where the two columns meet; the lighting looks the same in color, direction, and softness on both ducks; there is no visible flicker, repeated frame, or stutter in the motion of either duck across the clip.
level_5: Everything described for score 4 is present, and in addition the boundary between the two columns shows no visible color mismatch or ghosting where the backgrounds meet; neither duck's posture, size, nor apparent camera angle changes across the clip; the ambient lighting, shadow softness, and background detail stay visually constant throughout, so the whole frame reads as one continuous, physically consistent shot.