Research Reveals Global Warming Is Making Birds Smaller

Researchers have determined that birds are gradually shrinking as the global temperatures continue to rise, and the climate becomes warmer. The claims were part of a study that was published in the Ecology Letters journal.

The researchers were led by experts from the University of Michigan who analyzed more than 70,000 specimens from more than 50 migratory species in North America.

The specimens were collected between 1978 and 2016, and the findings were body sizes for all of the species had shrunk consistently.

On the other hand, the length of their wingspans increased, which means the birds have been forced to adapt in response to the changing climatic patterns.

Lead author on the project, Brian Weeks, an assistant professor at the school for environment and sustainability at the University, claimed the species range they tested were very diverse. However, they all responded in the same manner.

Apparently, the studies concerning the animal response to the changes in climate tend to focus on the shifts in the geographical range or event timing, such as migration and birth.

For this study, it was different because it suggested that bird morphology was something to consider.

He also said it was hard to understand the manner the species would adapt without taking all the factors above into consideration.

The evidence suggests warming temperatures caused a decrease in the size of the bird's bodies. It also led to an increased length of the wings of the birds.

Weeks stated the birds which are likely to survive a migration were the ones that had the biggest wingspans, which compensated for smaller bodies.

The researchers are not sure why the body sizes are significant adaptations when it comes to warm climates. The implication is the bodies of smaller animals have a better time cooling off and losing body heat because they have a large surface area to volume ratio.

Other research has also found that human activities considering the ecology have had a detrimental effect on the level of the bird population.

The bird specimens analyzed within the current study on wingspan were collected in Chicago after they died from colliding with buildings during the spring and fall migrations.

The birds tend to migrate at night, and the lights from the buildings attracted them, leading to the collisions.

Benjamin Winger, an assistant professor in ecology claimed the species tended to breed in the boreal forests of the north and the grasslands. Then they migrated through Chicago as they went south for the winter.