Responding to one report by the U.S. Fish and Wildlife Service (FWS), Interior Secretary Ken Salazar warned that migratory birds “are facing a new threat — climate change — that could dramatically alter their habitat and food supply and push many species towards extinction.”

The FWS report said that climate change will have an increasingly disruptive effect on bird species in all habitats, with oceanic and Hawaiian birds in greatest peril.

A separate study led by Josh van Buskirk of the University of Zurich points to a verification of Bergmann’s Rule, which says animals tend to become smaller in warmer climates.

Buskirk and his colleagues found that of the half a million birds measured while passing through Carnegie Museum’s Powdermill ringing station in Pennsylvania between 1961 to 2007, 60 of the 83 species caught in the spring migration now weigh less and have shorter wings.

The trend was said to be particularly noticeable among those birds that winter in the Caribbean, Central America and South America.

Photo: File