Exploring recent changes in bird morphology—probably due to global warming – Phys.org



Forget Password?
Learn more
share this!
69
14
Share
Email
April 5, 2022
by
Researchers at Tel Aviv University have found changes in the morphology of many birds in Israel over the past 70 years, which they interpret to be a response to climate change. The body mass of some species decreased, while in others body length increased—in both cases increasing the ratio between surface area and volume. The researchers contend that these are strategies to facilitate heat loss to the environment. The researchers state that “the birds evidently changed in response to the changing climate. However, this solution may not be fully adequate, especially as temperatures continue to rise.”

The study was led by Prof. Shai Meiri and Ph.D. student Shahar Dubiner of the School of Zoology, Wise Faculty of Life Sciences, and the Steinhardt Museum of Natural History at Tel Aviv University. The paper was published in Global Ecology and Biogeography.
Prof. Meiri explains that according to Bergmann’s rule, formulated in the 19th century, members of bird and living in a cold climate tend to be larger than members of the same living in a warmer climate. This is because the ratio of to volume is higher in smaller animals, permitting more heat loss (an advantage in warm regions), and lower in larger bodies, minimizing (a benefit in colder climates). Based on this rule scientists have recently predicted that global warming will lead to a reduction in animal size, with a possible exception: birds living in the (such as pigeons, house sparrows, and the hooded crow) may gain size due to increased food availability, a phenomenon already witnessed in mammals such as jackals and wolves.
Relying on the vast bird collection preserved by the Steinhardt Museum of Natural History at TAU, the researchers looked for changes in bird morphology over the past 70 years in Israel. They examined approximately 8,000 adult specimens of 106 different species—including migratory birds that annually pass through Israel (such as the common chiffchaff, white stork, and black buzzard), resident wild birds (like the Eurasian jay, Eurasian eagle-owl, and rock partridge), and commensal birds, that live near humans. They built a complex consisting of various parameters to assess morphological changes—in the birds’ body mass, body length and wing length—during the relevant period.
Shahar Dubiner says that their “findings revealed a complicated picture. We identified two different types of morphological changes: some species had become lighter—their mass had decreased while their body length remained unchanged; while others had become longer—their body length had increased, while their mass remained unchanged. These together represent more than half of the species examined, but there was practically no overlap between the two groups—almost none of the birds had become both lighter and longer. We think that these are two different strategies for coping with the same problem, namely the rising temperatures. In both cases, the surface area to volume ratio is increased (by either increasing the numerator or reducing the denominator)—which helps the body lose heat to its environment. The opposite, namely a decrease in this ratio, was not observed in any of the species.”
These findings were observed across the country, regardless of nutrition, and in all types of species: resident birds; commensal species living in the human environment—which, contrary to predictions, exhibited changes similar to those of other birds; and migrants. A difference was identified, however, between the two strategies: changes in tended to occur more in migrants, while changes in body mass were more typical of non-migratory birds. The very fact that such changes were found in coming from Asia, Europe, and Africa, suggests that we are witnessing a global phenomenon. The study also found that the impact of over time on bird morphology is 10 times greater than the impact of similar differences in temperature between geographical areas.
Dubiner continues that their “findings indicate that causes fast and significant changes in bird morphology. But what are the implications of these changes? Should we be concerned? Is this a problem, or rather an encouraging ability to adapt to a changing environment? Such morphological changes over a few decades probably do not represent an evolutionary adaptation, but rather certain phenotypic flexibility exhibited by the birds. We are concerned that over such a short period of time, there is a limit to the flexibility or evolutionary potential of these traits, and the might run out of effective solutions as temperatures continue to rise.”


Explore further

Migratory birds have lighter-colored feathers


More information: Shahar Dubiner et al, Widespread recent changes in morphology of Old World birds, global warming the immediate suspect, Global Ecology and Biogeography (2022). DOI: 10.1111/geb.13474

Journal information: Global Ecology and Biogeography

Citation: Exploring recent changes in bird morphology—probably due to global warming (2022, April 5) retrieved 22 April 2022 from https://phys.org/news/2022-04-exploring-bird-morphologyprobably-due-global.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further
Facebook
Twitter
Email
Feedback to editors
12 hours ago
0
12 hours ago
1
14 hours ago
0
14 hours ago
0
Apr 20, 2022
0
10 hours ago
10 hours ago
11 hours ago
11 hours ago
11 hours ago
11 hours ago
11 hours ago
7 hours ago
7 hours ago
7 hours ago
7 hours ago
7 hours ago
7 hours ago
More from Physics Forums | Science Articles, Homework Help, Discussion
Dec 06, 2021
Feb 10, 2022
Aug 12, 2021
Mar 18, 2020
Jun 21, 2021
Nov 12, 2021
13 hours ago
19 hours ago
11 hours ago
Apr 20, 2022
Apr 20, 2022
Apr 20, 2022
Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form. For general feedback, use the public comments section below (please adhere to guidelines).
Please select the most appropriate category to facilitate processing of your request
Thank you for taking time to provide your feedback to the editors.
Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.
Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient’s address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.

Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we’ll never share your details to third parties.
More information Privacy policy
Medical research advances and health news
The latest engineering, electronics and technology advances
The most comprehensive sci-tech news coverage on the web
This site uses cookies to assist with navigation, analyse your use of our services, collect data for ads personalisation and provide content from third parties. By using our site, you acknowledge that you have read and understand our Privacy Policy and Terms of Use.

source