Checking a hive in winter without killing it

The colony is not asleep and it is not idle. It is burning stores to hold a cluster near thirty-five degrees Celsius at the core, and every minute the lid is off costs it.

Do not open it

A full inspection in January tells you almost nothing you can act on and breaks the cluster's heat and the propolis seal the bees spent fall making. There is no version of a mid-winter frame-by-frame that is worth what it costs.

The decisions available to you in winter are narrow: feed or do not feed, ventilate or do not, and act on a dead-out. None of them requires pulling frames.

What the outside tells you

On a mild day above roughly ten degrees Celsius, look for cleansing flights. Bees leaving and returning on a warm afternoon means a living colony. Dead bees on the landing board is normal all winter and is not a signal on its own; a colony loses bees constantly and the survivors carry them out.

Put an ear to the side and tap once. A living colony answers with a brief rise in hum that settles. Silence on a cold day means you should listen again on a warmer one before concluding anything, because a tight cluster in deep cold can be very quiet.

Snow against the entrance is not the emergency it looks like, since snow is porous. A solid ice sheet across the entrance is, and so is a blocked upper vent with condensation running back down onto the cluster.

Hefting, and what weight means

Lift the back of the hive an inch. You are not measuring anything absolute, you are comparing to last month and to the hive beside it. A colony that felt heavy in November and feels light in February is consuming faster than it should and is the one to feed.

Do this every few weeks through the second half of winter, because consumption accelerates once brood rearing restarts in late winter, and that is when starvation happens. Colonies far more often starve in February and March than in December.

When opening is justified

To put solid feed directly above the cluster when hefting says it is light. Choose the warmest, calmest day available, lift the lid, place the feed, and close it. That is thirty seconds and it is a different act from an inspection.

Also to confirm a dead-out, which does no harm and lets you close the entrance against robbing and protect the comb, which is the most valuable thing left.

References