30-year snapshot shows many Pacific Northwest birds resilient ^{CEFR B1}

The research began when Benjamin Freeman, an assistant professor at Georgia Tech, found a thirty-year-old study by Louise Waterhouse that mapped bird communities near Vancouver. Using Waterhouse’s hand-drawn maps and his own local knowledge, Freeman and his team revisited the original field sites on foot. They often rose very early, sometimes at four in the morning, and worked during the birds’ breeding season from late May into June, even in snow and very cold conditions.

Comparing the two snapshots showed that temperatures have increased over the last 30 years but most bird populations in the region have not declined. Many species remained stable and became more abundant at higher elevations, though some species, such as the Canada Jay, are struggling. The team suggests that old-growth stands of trees may provide stable habitat and that conserving wide swaths of mountain habitat could help birds adapt. The study appears in the journal Ecology and was funded by the Packard Foundation. Researchers from several institutions also contributed.