Climate change a threat to birds...?

Climate change a threat to birds...?

Weak Signal's progress: nominated

This Weak Signal came from: 
Television/radio

The source of this Weak Signal: 
BBC News

Weak Signal's description 
Studies in North America are showing that over 100 species of birds are becoming lighter and growing smaller wings. It is thought that this may be a consequence of climate change and could eventually lead to flightless birds or the extinction of many species.