One doesn’t need to venture deep into the Amazon to see evolutionary biology at work. Rather, I simply look out my living room window. As an aspiring evolutionary biologist, I am interested in what factors are maintaining or degrading the species barrier between closely related species. Understanding what facilitates or prevents hybridization - interbreeding between distinct species - is important for not only understanding what maintains biodiversity, but also how anthropogenic influence affects the lives of our closest neighbors.
The black-capped chickadee (Poecile atricapillus) is the small song bird I see fluttering around my house every morning. Mountain chickadees (Poecile gambeli), on the other hand, are often my unknowing companion on hikes or rides in the mountains. In Boulder, where deciduous forest abruptly turns into coniferous forest at higher elevations, black-capped and mountain chickadees interact and occasionally hybridize. I am broadly interested in what factors may be contributing to the breakdown in this species barrier. To address this, I am studying how plumage varies between and within black-capped and mountain chickadees. Understanding how plumage varies is important because it will provide insight into whether plumage may be an ambiguous signal in between-species communication. If signals are ambiguous between black-capped and mountain chickadees, then hybridization and the subsequent breakdown of their species barrier could occur. To eventually understand what is maintaining or degrading their species barrier, we must answer the first question in the larger story: how does plumage vary between and within black-capped and mountain chickadees?