Dramatic decline of aerial insectivores in Vermont

Fewer birds appear to live in Vermont today than 25 years ago, according to recent research by the Vermont Center for Ecostudies. The most dramatic declines in bird populations were seen among those that live off flying insects, scientists say. Known as aerial insectivores, this diverse group of birds has declined 45 percent in Vermont, according to the study. The study focused on 11 species of aerial insectivores that were among the 13 species of Vermont birds found to have undergone the most serious declines, said Steve Faccio, one of the study’s authors and the co-founder of the Vermont Center for Ecostudies. This group of birds includes the tree swallow (Tachycineta bicolor), the yellow-bellied flycatcher (Empidonax flaviventris), the chimney swift (Chaetura pelagica) and the eastern wood pewee (Contopus virens). This dropoff in insect eaters mirrors a trend seen nationwide in recent decades, Faccio said. These birds’ food — aerial insects — is what the species in this highly varied group have in common, leading scientists to suspect that some widespread trend among flying insects is what’s driving the decline in birds that eat them, Faccio said.
Source: VT Digger, April 17, 2017