While the hippocampus volume in lab-reared birds was not different between Alaska and Kansas chickadees, the total number of hippocampal neurons and hippocampal neurogenesis rates were sigbnfciantly different. Moreover, the total number of hippocampal neurons and hippocampal neurogenesis rates in 'common garden' birds were similar to those in wild birds from the same populations. So despite spending their entire life in the lab, lab-reared chickadees has similar number of neurons and similar neurogenesis rates to birds from the wild. These results support the idea that differences between Alaska and Kansas chickadees is mainly driven by some heritable mechanisms.