Density and survival of wild honey bee colonies in English wood pasture, parkland and deer parks

Abstract Honey bees are possibly unique amongst managed animals in that a significant part of their global population is wild. More data regarding wild colony density and survival are needed to assess the size and status of wild populations in the honey bee’s native range. Previous studies from parts of central Europe have reported low densities (<0.5 colonies/km 2 ) and annual survival rates (<0.15) of wild colonies, indicating that they might just be swarms that have escaped from apiaries in some places. Here, we report the results of a 3.5-year monitoring study of wild colonies living in wood pasture, parkland and deer parks (“landed estates”) in southeast England. Sixty-three honey bee nest sites were found across six landed estates and checked three times a year to determine colony survival rates. Wild colonies occupied cavities in trees (89%) and buildings (11%) at an average density of 2.5 colonies/km 2 . We found no evidence of spatial aggregation amongst active nest sites, although there was a significant positive association between wild colony occurrence and veteran tree distributions. Wild colonies had an annual survival rate of 0.41, meaning that colonies active in late spring and early summer would need to produce an average of 1.4 swarms each year for the population to be self-sustaining, which is within the range of swarming rates reported for unmanaged colonies. Our results suggest that wild honey bee colonies on landed estates in southeast England are not just swarms that have escaped from apiaries and potentially represent additional genetic variation that can be used in beekeeping.