Winter survival surveys show ‘treatment-free’ works

Each May OxNatBees surveys our members for information on winter losses. This graph shows losses year by year, compared with other surveys. The stand-out point is that our losses for untreated hives populated by local bees (blue “ONBG” line) are essentially the same as for heavily managed colonies (the red “BBKA” line).

Discussion

  • Colony survival rates for natural beekeeping techniques are essentially the same as for the intensive-intervention techniques the BBKA promotes. However we measure “survival” more harshly than the BBKA: they don’t even bother recording results for small colonies <5 frames going into winter, and they sometimes replace queens with artificially raised new queens before winter (which we would count as a colony death). And they take lots of honey. And feed immense amounts of sugar syrup. So direct comparisons are questionable.
  • The bulk of winter losses were queen failure (colony dwindling away). We also find a small colony is a risk factor, making other failure modes more likely: a couple starved, one hive was knocked upside down; one suddenly failed, wasps and hornets were seen in it.
  • None of the group has ever reported a loss due to varroosis.
  • We use swarms from local bees, mainly from non-treated hives and unmanaged wild colonies, of which there are many around here, mainly in the roofs of old houses. A few of us have started off with bees from commercial sources, which are then allowed to open mate with the local landrace. Some swarms are of unknown origin.
  • Most of our hives are Warrés and Top Bar Hives, with a real mix of other types. Most of them are better insulated than a standard National, but half of conventional beekeepers now at least add top insulation.
  • To improve our husbandry, our survey asks questions on management practises and local conditions. After 5 years, no significant patterns have yet emerged! There’s no consistent geographical cluster, i.e. no particularly bad spot in Oxfordshire. It doesn’t seem to make a difference if you use an open mesh floor or a solid one over winter. Even the experience of the beekeeper seems almost irrelevant, probably precisely because of our hands-off approach. The consistent primary factor influencing winter survival seems to be queen failure, which really old beekeepers in the area reckon used to be much lower and may be linked to pesticides.
  • The members are very firmly in the low intervention camp. Typical inspections are: entrance observations – daily to weekly; internal inspections – rarely to never. This permits the bees to use the pest control responses they’ve evolved over millions of years to maintain their health: propolis, grooming, hygiene, high temperature and humidity. We get lower honey harvests but are not continuously stressing the bees at the limit of their endurance.
  • Note the consistently high US losses.

Other surveys

The BBKA winter survival survey is similar and it subdivides area results – Oxfordshire apparently falls in the BBKA Southern region (orange dotted line). The results above are from July’s BBKA News, they are not yet published on the BBKA website. This has some interesting results showing about 37% of British beekeepers did not use miticides over winter (and 25% didn’t in the summer either) yet 97% of colonies don’t seem to have deformed wings, which seems to imply varroa are a declining problem for whatever reason.

The American results above are from BeeInformed. Other possible surveys don’t really compare like-with like:

USDA survey – segments winter into two periods.

COLOSS international survey – has only covered England for a couple of years. Results for this year not yet published.

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