Why Chimney Swifts ?
Chimney Swifts (Chaetura palegica) appear as silhouettes dancing through the sky, chattering away, and eating insects from dawn until dusk. Large colonies form tornado-like funnels as they descend into chimneys at dusk and are often mistaken for bats.
These large colonies appear most often during peak migrations; migrating individuals share roosting habitat during the long journey to South America. The large size of these colonies is misleading, however, because Chimney Swift populations have been declining sharply since the ~1960s (i.e., IUCN “near threatened” in the US, COSEWIC “federally threatened” in Canada). While the causes of these declines are manifold, loss of breeding habitat (e.g., hollow trees, un-capped masonry chimneys) is the primary culprit behind these declines.
Historically, chimney swifts preferred hollow trees as nesting and roosting sites. However, as European expansion replaced forests with towns this resilient species adapted by using chimneys. More recently, however, the increased use of chimney-caps and fabricated chimneys has made finding suitable habitat challenging. This gregarious species roosts (i.e., rests and sleeps) communally.
However, only one pair breeds at each site (as a territorial species they require ≥ 10 ft. in between nesting sites).
Therefore, increased breeding habitat is essential to reducing two of the primary threats facing small populations: 1) loss of genetic diversity (i.e., from inbreeding) and 2) falling below their “minimum viable population size”; below this threshold, recovery becomes increasingly difficult. Luckily, this species responds remarkably well to “Swift-towers” and modified chimney-caps making conservation efforts relatively straightforward and promising.