Shrinking birds - Innovation America

Global temperatures have risen an average of 0.6 degrees Celsius in the last century. What effect that may have on the planet’s species is hard to predict, but a recent paper evaluating data from more than 100 different bird species over the past 5 decades found that many of them have shrunk in size. F1000 Faculty Member and evolutionary biologist at the University of Melbourne, Ary Hoffmann, talked about what this may mean in the long run (Oikos, 119:1047–55, 2010).

TS: Naturalists have long observed that species tend to get smaller if they live in warmer areas. Robert Leberman and colleagues from the University of Zürich used this observation to hypothesize that as the Earth warms up, birds that either resided in or made pit stops at a bird-banding station in Pennsylvania will get smaller over time. Does their study give strong evidence to both of these theories?

AH: Organisms are getting smaller. So it does look like there are these general patterns in size that seem to be related to conditions getting warmer in particular. I think what’s really nice about this study is the number of species that were actually showing the same patterns. Previously people had taken one or two species and shown these kinds of patterns. If you’re trying to establish patterns related to climate change, I think this study does emphasize the fact that you need to look at a large number of species—simply because we know there is a wide range of factors that can actually influence size, such as food availability. The surprise is that you’re seeing these consistent patterns across a large number of species.

To read the full, original article click on this link: Shrinking birds - The Scientist - Magazine of the Life Sciences

Author: Ary Hoffmann