Featured Research

from universities, journals, and other organizations

Hue of barn swallow breast feathers can influence their health

Date:
August 21, 2013
Source:
University of Colorado at Boulder
Summary:
A new study shows the outward appearance of female barn swallows, specifically the hue of their chestnut-colored breast feathers, has an influence on their physiological health.

CU-Boulder Assistant Professor Rebecca Safran, colleagues and students are working on a long-term project looking at the reproductive strategies and evolution of North American barn swallows.
Credit: Kevin Stearns

A new study conducted at the University of Colorado Boulder and involving Cornell University shows the outward appearance of female barn swallows, specifically the hue of their chestnut-colored breast feathers, has an influence on their physiological health.

It has been known that in North American barn swallows, both males and females, those with darker ventral feathers have higher reproductive success than those with lighter colors, said Cornell Senior Research Associate Maren Vitousek, who led the new research while a postdoctoral researcher at CU-Boulder. Although there is evidence that breast feather color is significantly influenced by genetics, melanin-based plumage color like that in barn swallows also has been tied to social status and even to circulating testosterone, she said.

The new study showed that both naturally darker barn swallow females and those with artificially darkened breast feathers also had lower levels of oxidative damage, which could ultimately make the birds healthier. Oxidative stress results when the production of harmful metabolites known as free radicals exceeds antioxidant defenses in the birds, which can lead to DNA, protein and fat damage in the birds, said Vitousek.

"Intriguingly, females whose feathers were darkened to resemble 'attractive' birds rapidly adopted the physiological state of darker birds, decreasing their level of oxidative damage," said Vitousek. "These results suggest the appearance of an individual may be an under-appreciated driver of physiological health."

A paper on the subject by Vitousek, CU-Boulder Assistant Professor Rebecca Safran and Indiana University Research Associate Rosemary Stewart appeared in the Aug. 21 online edition of Biology Letters, a publication of the Royal Society in London. The National Science Foundation, the Max Planck Institute in Radolfzell, Germany, and CU-Boulder funded the study.

A 2008 study led by CU-Boulder's Safran showed the testosterone of male North American barn swallows skyrocketed early in the breeding season when their breast colors were artificially enhanced by researchers, indicating the clothes -- or in this case, the feathers -- make the man. The study was the first to show significant feedback between physical appearance and physiology in birds, with implications for better understanding the ecology and evolution of physical signals such as feather color.

"Features of an individual bird's appearance are often signals of a physiological condition, health and status, but little is known about how these relationships are formed," said Safran of CU-Boulder's ecology and evolutionary biology department. "The twist in our new study is that the same color manipulation in males and females induced opposite effects on testosterone: It goes up in darkened males and goes down in darkened females."

For the new barn swallow study, Vitousek, Safran and a team of undergraduate and graduate students captured 60 female barn swallows with mist nets in Boulder and Jefferson counties near Denver. Thirty of the birds were used as the control group, while the other 30 had their ventral plumage darkened using a non-toxic marker. The testosterone, oxidative damage and antioxidant levels of all birds were measured at that time. The birds were then released back into the wild.

Between one and three weeks later, 19 of the artificially darkened females and 17 birds from the control group were recaptured, re-tested for testosterone, oxidative damage and antioxidant levels and then released back into the wild, said Vitousek.


Story Source:

The above story is based on materials provided by University of Colorado at Boulder. Note: Materials may be edited for content and length.


Cite This Page:

University of Colorado at Boulder. "Hue of barn swallow breast feathers can influence their health." ScienceDaily. ScienceDaily, 21 August 2013. <www.sciencedaily.com/releases/2013/08/130821094918.htm>.
University of Colorado at Boulder. (2013, August 21). Hue of barn swallow breast feathers can influence their health. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2013/08/130821094918.htm
University of Colorado at Boulder. "Hue of barn swallow breast feathers can influence their health." ScienceDaily. www.sciencedaily.com/releases/2013/08/130821094918.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins