What specific environmental disturbance affecting hemlock trees poses a threat to the breeding success of this species?

Answer

Hemlock woolly adelgid

The reliance on specific mature conifers means that diseases affecting key nesting trees, such as the hemlock woolly adelgid impacting hemlocks, can severely impact local breeding success.

What specific environmental disturbance affecting hemlock trees poses a threat to the breeding success of this species?
speciesbirdornithologyanimalwarbler