Colony losses explained

What a loss survey actually measures

The headline loss figures come from voluntary surveys in which beekeepers report how many colonies they had going into winter and how many came out. That is a specific measurement with specific limits, and almost every misreading follows from ignoring them.

• It is beekeeper-reported, not independently verified, and respondents self-select — the people who answer surveys are not a random sample of beekeepers.
• It covers ONE country, or sometimes one region, in ONE season. A loss rate from one national survey is not a global figure and moves substantially year to year.
• The definition of a loss varies between surveys — whether a colony that dwindled but survived counts, whether queen failure counts separately, whether losses in transit are included.
• It measures colonies, not bees, and a colony is a unit of husbandry rather than an organism.

None of this makes the surveys useless. They are the best instrument available for a real problem, they have been run consistently enough to show trends, and a loss rate that stays high for two decades is telling you something. It simply is not telling you what the phrase 'a third of bees died' implies.

Why the number does not mean extinction

The real consequence falls on beekeepers rather than on the bee. Replacing a third of your colonies every year is a substantial recurring cost in money, labour and forgone production, and it is the reason a loss rate is worth tracking even though nothing is going extinct.

It is also worth saying that this is not new. Beekeepers lost colonies over winter long before anybody surveyed it — disease, starvation, queen failure and hard winters are old problems. What is arguable is whether current rates are higher than historical ones, and the honest answer is that the historical baseline is poorly measured because nobody was systematically counting.

What is driving them

The consensus is that no single cause accounts for the pattern, and that the interaction is the point. Varroa and the viruses it amplifies are consistently identified as a leading factor in regions where the mite is established; poor nutrition from monotonous or scarce forage, pesticide exposure, queen failure, weather and management practice all appear in the literature and in beekeeper reporting.

Attributing a given loss to one cause is genuinely hard, because the pressures compound: a colony carrying a heavy mite load, on poor forage, hit by a bad autumn, fails for all three reasons at once. Any account that names one villain is simplifying past the evidence — and this is equally true of accounts naming pesticides alone and accounts naming varroa alone.

And it is not the same question as wild pollinator decline

Managed colony losses and wild bee decline are different problems with different evidence, different drivers and different remedies. Wild bees are not replaced by a beekeeper in spring. HoneyHQ keeps them on separate pages for that reason, and the pollinator-decline guide is where the wild side is assessed.