Gender imbalance threatens a New England alpine songbird

Maine Public has a story (here it is) about efforts to save the Bicknell’s thrush, which nests in balsam fir trees on the alpine climate of the Northeast and winters down in the Caribbean. The population is declining about 4% a year, which is a lot.

For reasons scientists don’t yet understand, there are a lot more male birds than females in the adult population. The theory is that the females aren’t surviving the winters, and that this imbalance is causing their populations to dwindle.

The long-term concern, of course, is that climate change will shrink out alpine forests, leaving the tin y thrush in big trouble.