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New Study: Migratory Birds Are Shrinking As a Consequence of Climate Change

A University of Michigan-led study of approximately 70,000 North American migratory birds from 52 species found that body sizes have decreased and wing length has increased in all of the species since 1978. 

David Willard, a Field Museum ornithologist, has measured the Windy City's dead birds since 1978. Data from his calipers and scales reveal decades-long trends in bird bodies: Their legs, on average, are growing shorter. They have lost weight. Their wings are getting slightly longer.
These changes are present in nearly all of the species he measured, according to a study of 70,716 bird specimens from almost 40 years published Wednesday in the journal Ecology Letters. Morphing birds, Willard, and his colleagues say, reflect a changing climate: "Our findings suggest that warming‐induced body size reduction is a general response to climate change, and reveal a similarly consistent and unexpected shift in body shape. We hypothesise that increasing wing length represents a compensatory adaptation to maintain migration as reductions in body size have increased the metabolic cost of flight". 

h/t: WashingtonPost

birds are shrinking due to climate change
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Fascinating Animal Migration Photos

Seeing an animal roaming in the wild can be fun, but seeing hundreds or thousands of them traveling in huge groups is certainly overwhelming and fascinating. These photos are stunning proofs of nature's beauty in the form of migration.

photos of animal migration during the year
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