Elevation-related differences in novel environment exploration and social dominance in food-caching mountain chickadees

Abstract

Harsh and unpredictable environments have been assumed to favor the evolution of better learning abilities in animals. At the same time, individual variation in learning abilities might be associated with variation in other correlated traits potentially forming a behavioral syndrome. We have previously reported significant elevation-related differences in spatial memory and the hippocampus in food-caching mountain chickadees. Here, we tested for elevation-related differences in novel environment exploration, neophobia, and social dominance—behavioral traits previously thought to correlate with individual variation in cognition, using different birds from the same elevations. Compared to low-elevation birds, high-elevation chickadees were slower at novel environment exploration, but there were no detectable differences in neophobia. High-elevation chickadees were also socially subordinate to low-elevation chickadees in pairwise interactions. Considering previously reported elevation-related differences in cognition and the brain, our results suggest, however indirectly, that elevation-related variation in spatial memory might be associated with differences in novel environment exploration and in ability to obtain a high social rank in winter social groups. Whether these behavioral traits represent a behavioral syndrome or whether climate might affect these traits independently, our results suggest that multiple differences between elevations might assist with elevation-related separation. High-elevation chickadees would likely experience higher mortality if they move to lower elevation due to their low social dominance status and low-elevation chickadees might experience higher mortality if they move to higher elevation due to reduced memory ability and lack of behavioral adaptations to colder climate.