FA-65782 / Ecological population dynamics / Member archive

Monthly population with seasonal breeding window: survival before births · case 02

Newborns are subjected to the month's mortality.

Member previewVariant 2 · 3 implementations · 7 checks per implementation

Case contract

Calendar month of step t is ((start_month-1+t) mod 12)+1; the breeding window is inclusive and may wrap across the new year (start > end); each month survival is applied first, then in breeding months births fecundity*N*max(0,1-N/cap); return monthly N rounded 4.

Why this case matters

Population projections set harvest quotas, conservation status and pest-control timing; a wrong update order, boundary or rate conversion silently changes management advice.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: deer spring births	`[97.0, 94.09, 119.1869, 148.0764, 143.6341, 139.3251]`	`[97.0, 94.09, 119.4445, 148.7818, 144.3184, 139.9888]`	Failed

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