The Relationship between Environment, Behavior, Cognition, and the Brain, in Specialized Food-Caching Chickadees (Poecile Gambeli

Environmental heterogeneity is known to affect phenotypic variation. Behavioral traits and the brain regions controlling these traits may be especially variable across environmental gradients as behavioral traits change rapidly in response to environment. Behavioral traits have been shown to differ across several environmental gradients of climatic harshness and novelty, such as latitudinal, elevational and urbanization gradients. This dissertation focuses on how cognition, behavior and the brain differ food-caching specialists inhabiting environments that differ in climatic harshness (i.e. differ in elevation) and novelty (i.e. differ in anthropogenic activity). I found that, chickadees from harsher high elevations, when compared with low elevation chickadees, have better problem-solving abilities and that these chickadees with better cognition are less willing to take risks when perceived predation risk is high, which resulted in a reduced investment in current offspring. I also found that chickadees from urban environments had a suite of generalist traits (e.g. more active in exploring a novel environment, better problem-solving abilities and larger brains) and some food-caching specialist traits (e.g. better long-term spatial memory retention) when compared with forest chickadees. This dissertation highlights that unique suites of behavioral traits are associated with different environments and suggests that a better understanding of how specific environmental factors affect specific (suites of) traits is necessary.