The organization BirdLife recently reviewed seven of bird species that were once considered quite common and widespread, but whose numbers are now plummeting.
Some of the species are unexpected. Three of these occur in North America:
Snowy Owl - Experiencing a rapid decline, most likely driven by climate change. Disruptions to snowmelt and snow cover can affect the availability and distribution of prey.
Atlantic Puffin - Regional overfishing and climate change have created serious food shortages.
Black-legged Kittiwake - Rising sea temperatures are driving catastrophic declines in plankton populations, with an impact to the rest of the food chain, including fish. Plastics at sea (consumed by the kittiwakes) may be another threat.
This information comes from The Birding Community E-bulletin, sponsored by Carl Zeiss Sports Optics, and sent free to subscribers (http://tinyurl.com/E-bulletinSIGNUP). An archive of past issues is at http://refugeassociation.org/news/birding-bulletin/
Black-legged Kittiwake photographed on a rare visit to Minnesota