Bird of a feather, flock — ahem, mate — together? New research published in Global Change Biology has found that hybrids of two common North American songbirds — the black-capped and mountain chickadee — are more common in places where humans have altered the landscape. The study is the first to examine the correlation separate from climate change. (Climate change can lead to overlaps in range, bringing together species that did not used to have contact.)
“What are the consequences of the ways we modify the landscape? We think about it mostly in terms of habitat loss, not necessarily in terms of species interaction modifications,” said Scott Taylor, co-author on the study. The hybridization is unlikely to lead to the creation of a new chickadee species as the female hybrids from black-capped and mountain chickadee parents are likely to be sterile. Male hybrids can reproduce and seem to do so predominantly with black-capped chickadees. “It’s hard to say whether this hybridization is good or bad, but it’s happening, and we will only understand the impacts through continued study,” said Taylor in a news release about the findings.