Patrick Laurenz Kohl , Benjamin Rutschmann

The population trends of wild western honeybees (Apis mellifera) have been neglected by conservationists because the species has been considered to consist of managed colonies only, leading to its current European IUCN Red List category “Data Deficient”. New data suggests that wild honeybee colonies (still) make up one sixth to one fifth of the overall European honeybee population. The population trends of wild cohorts can be evaluated like those of any other native wild species, albeit with some methodological adjustments to account for the bias introduced by swarms emigrating from managed cohorts. We used data on wild colony survival rates from six European countries to model their autonomous population changes over ten-year periods, the time frame considered for population evaluation by the IUCN. Populations of wild honeybee colonies currently represent demographic sinks in five out of six countries. With an average estimated population decline of 60% per decade, the honeybee should be considered “Endangered” in the wild in Europe. We believe that the formal recognition of wild honeybee colonies’ existence and the explicit study of their population trends beyond apiculture can have far-reaching consequences for the evolution of this unique species and bee conservation in general.