A nucleus colony ("nuc") is a small, complete colony kept on 2–6 frames for one of three production roles. Each role has its own population and queen-status curve driven by the same seasonal-warmth signal:
warmth(day) = 0.5 − 0.5·cos(2π·(day−15)/365) // 0=deep winter, 1=peak summer
capacity = frames / 6 // box-size fraction of a full 6-frame nuc
- Mating nuc — cycles a virgin queen roughly every 21 days: orienting (days 0–3), mating flights (3–10), then mated & laying (10–21). Population stays small and stable so the nuc can be reused for the next queen.
- Spring increase nuc — population tracks
warmth × feedBoost × capacity toward the frame capacity; once population exceeds ~88% of capacity it is ready to split into a full hive.
- Overwintering nuc — population contracts as
chill = 1 − warmth grows, clustering tightly below 35% warmth; survival odds scale with frame count, capacity and whether syrup feed is on.
Supplemental feed multiplies growth/survival terms by 1.18×. Brood-patch size on each frame scales with laying × population fraction; the year curve below re-evaluates this exact model at every day of the year for the current role, frame count and feed setting.