Ancient, veteran and other listed trees as nest sites for wild-living honey bee, Apis mellifera, colonies

Abstract

Wild-living honey bee (Apis mellifera) colonies naturally nest in old cavity-bearing trees throughout their range, but this important nesting habitat is in global decline. Here we determine the use of ancient, veteran and other listed trees as nest sites by wild-living honey bee colonies in Britain and investigate the effect of tree size, genus and management on occupancy. Over 1,000 trees of special interest (TSIs) were surveyed in southeast England using the Ancient Tree Inventory (ATI) of the Woodland Trust, a charity that protects and promotes trees in Britain. 2% of all TSIs and 4.4% of TSIs with cavities were occupied by wild-living honey bee colonies (n = 21). Occupancy positively correlated with tree diameter, which is surprising given that the overall sample already had a large mean diameter of 1.3 m. Wild-living colonies occupied sweet chestnut (Castanea sativa) more frequently than expected (7% versus 2% overall), probably due to their large mean diameter (1.6 m) and proportion of trees with cavities (73%). Heights of occupied tree cavities (including non-ATI trees) ranged from 0 to 18.2 m with a median of 6.8 m, entrance size ranged from 2.2 to 322 cm2 with a median of 33.8 cm2 and entrance orientation was not significantly different from random.