Grinnelian and Eltonian niche conservatism of the European honeybee (Apis mellifera) in its exotic distribution

The understanding of how niche-related traits change during species invasion have prompted what is now known as the niche conservatism principle. Most studies that have tested the niche conservatism principle have focused on the extent to which the species’ climatic niches remain stable in their exotic distribution. However, it is equality important to address how biotic specialization, i.e. resource use, changes during exotic species invasions. Here, we use the widespread European honeybee (Apis mellifera) to understand whether its Grinnelian and Eltonian niches changed in its exotic distribution using tests of abiotic and biotic niche conservatism. We found that both niche domains of the European honeybee remained stable in its exotic distribution, which means that neither the climatic niche nor the biotic specialization showed significant differences between the native and the exotic ranges. Our findings that climatic and resource use are coupled can be explained by A. mellifera’s long history of domestication and the possibility that life history traits (e.g., polyandry) may have shaped this species’ large niche over the course of evolution and therefore facilitated exotic ranges colonization.