Migratory birds shrinking as climate warms, new analysis of four-decade record shows

phys.org | 10/11/2019 | Staff
Sugar12Sugar12 (Posted by) Level 4
Click For Photo: https://scx2.b-cdn.net/gfx/news/hires/2019/3-migratorybir.jpg

University of Michigan evolutionary biologist Benjamin Winger with some of the migratory songbirds used in a large study of avian responses to climate warming. Credit: Roger Hart/University of Michigan Photography.

North American migratory birds have been getting smaller over the past four decades, and their wings have gotten a bit longer. Both changes appear to be responses to a warming climate.

Findings - University - Michigan-led - Analysis - Dataset

Those are the main findings from a new University of Michigan-led analysis of a dataset of some 70,000 North American migratory birds from 52 species that died when they collided with buildings in Chicago.

Since 1978, Field Museum personnel and volunteers have retrieved dead birds that collided with Chicago buildings during spring and fall migrations. For each specimen, multiple body measurements are made.

Research - Team - Dataset - Trends - Body

The research team analyzed this remarkably detailed dataset to look for trends in body size and shape. The biologists found that, from 1978 through 2016, body size decreased in all 52 species, with statistically significant declines in 49 species.

Over the same period, wing length increased significantly in 40 species. The findings are scheduled for publication Dec. 4 in the journal Ecology Letters.

Reason - Temperatures - Reductions - Body - Size

"We had good reason to expect that increasing temperatures would lead to reductions in body size, based on previous studies. The thing that was shocking was how consistent it was. I was incredibly surprised that all of these species are responding in such similar ways," said study lead author Brian Weeks, an assistant professor at the U-M School for Environment and Sustainability.

The senior author is Benjamin Winger of the U-M Department of Ecology and Evolutionary Biology and the Museum of Zoology. Weeks worked on the project as a postdoctoral researcher in Winger's lab. Co-authors include David E. Willard, the Field Museum ornithologist and collections manager emeritus who measured all 70,716 birds analyzed in the study.

Study

The new study is the...
(Excerpt) Read more at: phys.org
Wake Up To Breaking News!
Merry Christmas! It's not just for December any longer!
Sign In or Register to comment.

Welcome to Long Room!

Where The World Finds Its News!