Domain: Natural Science — Morphology
Target concept: Sexual Dimorphism in Peafowl: Tail Fan Display in Male Peacocks vs. Plumage in Female Peacocks

Video generation prompt: Male peacocks court females, and their tail feathers contrast sharply with the females' plumage.

Evaluation guide:
(i) Target concept: Sexual dimorphism manifests as irreversible, species-typical morphological divergence between sexes, driven by sexual selection on males and natural selection on females.
Minimum mechanism: Male must possess genetically fixed, developmentally mature upper-tail coverts capable of bilateral symmetric deployment; female must lack elongated upper-tail coverts and the eye-spotted train, though she may naturally show a modest iridescent green sheen on her neck/upper breast; no hormonal manipulation or artificial enhancement permitted.
(ii)Storyline: Frame 1–2s: Both peacocks enter static, adjacent positions in shared natural environment. Frame 3–4s: Male rotates torso to face female, lowers wings slightly, begins lifting upper-tail coverts. Frame 5–7s: Male completes full tail fan deployment (symmetrical, vertical, ocelli fully exposed). Frame 8–10s: Female remains stationary, facing forward or slightly toward male, with no change in plumage appearance; visual contrast between male"s iridescent fan and female"s plain body plumage is continuously and unambiguously visible. Perspective: Fixed frontal or 3/4 frontal view, sufficient to resolve feather structure and color differentiation; no obstructions; consistent lighting from above-frontal natural source.

Manual:
Experimental Procedure
1. Place one adult male peacock and one adult female peacock side-by-side in natural daylight setting.
2. Wait for male to initiate courtship: he turns toward female and slowly spreads his upper-tail coverts into a vertical fan.
3. Observe plumage contrast while fan is fully displayed.
Observation of Experimental Phenomena
Male displays large, iridescent, eye-spotted tail fan; female shows brown/tan mottled body plumage with no train feathers or eye-spots, though her neck/upper breast may retain a natural, modest green sheen.
Summary of Experimental Principles
Sexual dimorphism in peafowl: males evolved elaborate, colorful tail fans for mate attraction; females evolved cryptic, camouflaged body plumage (aside from a small iridescent neck patch) suited to nesting survival.

Prompt Grounding rubric:
level_1: No peacock or peahen appears at all, only one of the two sexes appears, the birds shown are a different species (e.g., pheasant, turkey), or the male never raises any tail feathers.
level_2: Both birds appear but not together in one continuous shot (e.g., cut to two separate clips or a split screen), the male's tail feathers never lift into a fan shape, or the female is drawn with long ornamental tail feathers of her own.
level_3: Both birds share one continuous scene, positioned near each other, with the male's tail raised into a fan shape and the female showing a plain, brownish body, but the fan is partly hidden from view, or the female's plumage looks about as bright and colorful as the male's due to lighting or angle.
level_4: Both birds stay fully visible in the same scene, the male's fan is spread open widely enough to show its blue-green coloring and eye-spot pattern, and the female's plain brown/tan body plumage is clearly visible, with only a brief, isolated glitch such as a short flicker or slight jerky motion affecting one bird.
level_5: Both birds stay continuously and fully visible in one fixed scene, the male's fan is completely open and symmetrical with its blue-green iridescent eye-spots plainly visible, and the female's plain, non-ornamental body plumage is unobstructed and unambiguous for the whole clip, with no cut, occlusion, or moment where either bird's key features are hidden.

Scientific and Causal Correctness rubric:
level_1: The male never spreads or shows any tail fan display at all, the female is shown with an elongated, eye-spotted tail fan or train like the male's, or the two birds' plumage looks essentially identical.
level_2: The male's tail fan is only partly raised (less than half its feathers lifted, or clearly lopsided) or lacks visible eye-spot patterning, the female is shown growing long ornamental train feathers or eye-spots of her own, or the male and female's overall coloring appears swapped (male plain, female showing peacock-blue/green train coloring).
level_3: The male shows a tail fan with visible blue-green sheen and eye-spot patterning, and the female shows an overall brown/tan body without any train or eye-spots, but the fan looks flat or washed-out in color, or the female is never oriented so her plain body plumage is visible, weakening the contrast between them.
level_4: The male's fan is clearly iridescent with visible eye-spots and is oriented toward the female; the female's body plumage is brown/tan and she grows no train feathers or eye-spots of her own (a natural green sheen on her neck or upper breast, if shown, is fine), but one small inconsistency remains, such as the male briefly lowering the fan or the female shifting out of clear view.
level_5: The male continuously holds a fully spread, vividly iridescent blue-green fan with sharply visible eye-spots, facing the female; the female's body stays brown/tan and mottled with no train feathers and no eye-spots, and any green sheen on her is confined to the neck/upper-breast area rather than spreading into a fan of her own; the male's display together with the female's stationary, attentive posture reads clearly as a courtship interaction.

Spatiotemporal Consistency rubric:
level_1: One bird drops out of the shot and reappears somewhere else, the fan appears or disappears with no spreading motion at all, the setting behind the birds changes abruptly (e.g., forest cutting to a plain studio backdrop), or the overall brightness of the scene jumps sharply within a second.
level_2: A bird moves in a way real peafowl can't (gliding without leg movement, floating, or rotating in place), the tail fan looks like separate flat panels rather than one connected structure, or one bird looks noticeably brighter or dimmer than the other (affecting more than about half of that bird's body), with nothing in the scene explaining why.
level_3: The fan's opening is not perfectly smooth (it catches or hitches briefly partway through), the camera appears to shift position slightly partway through the clip, or the fan's feather edges look slightly uneven from moment to moment, but both birds stay fully visible, intact, and in a coherent scene throughout.
level_4: The male's approach and fan-opening motion looks like real leg and feather movement, with no vanishing, floating, or mismatched lighting between the two birds, apart from one small, isolated slip, such as a leaf or branch briefly covering the female's head before clearing, or a moment where overlapping feathers look slightly flattened.
level_5: Both birds keep steady positions and a consistent size relative to each other throughout, every movement (the male's approach, feather spreading, any head turns) looks like natural, physically grounded bird motion with no floating or feathers passing through each other, the scene's brightness and light angle stay steady from one end of the clip to the other, and there is no freeze, stutter, or sudden jump in the pacing of the male's display.