Invasive insects damage bird habitat

[Cara J]

Birds that specialize on eastern hemlock forests have been declining as a result of an invasive insect devastating the trees, according to new research. Researchers knew from past studies that eastern hemlock is important for some bird communities. There had also been previous data looking at hemlock conditions and extrapolating the differences in habitat after insect infestation. But until recently, there hadn’t been any long-term research looking at these effects on the bird community before and after infestation of the hemlock woolly adelgid (Adelges tsugae). “We were fortunate that previous researchers had collected baseline data in the year 2000 at the Delaware Water Gap National Recreation Area, which borders Pennsylvania and New Jersey,” said Matt Toenies, a former graduate student in the ecology program at Pennsylvania State University and lead author of a recent study published in The Condor: Ornithological Applications. The East Asian insects had arrived when the data was collected, Toenies said, but they hadn’t yet affected the trees. Researchers were able to compare that data with what they found some 15 years later. The team determined that birds specialized to hemlock — such as the Acadian flycatcher (Empidonax virescens), blue-headed vireo (Vireo solitarius), hermit thrush (Catharus guttatus), [...]

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