Disturbance-mediated hybridization in black-capped and mountain chickadees

Human habitat disturbances can promote hybridization between closely related, but typically reproductively isolated, species. We explored whether human habitat disturbances are related to hybridization between two closely related songbirds, black capped and mountain chickadees, using both genomic and citizen science datasets. First, we genotyped individuals from across both species ranges using reduced representation genome sequencing and compared measures of genetic admixture to a composite measure of human landscape disturbance. We found that hybridization between black capped and mountain chickadees positively correlates with human habitat disturbances.