Featured Research

from universities, journals, and other organizations

Chernobyl's birds adapting to ionizing radiation

Date:
April 24, 2014
Source:
British Ecological Society (BES)
Summary:
Birds in the exclusion zone around Chernobyl are adapting to -- and may even be benefiting from -- long-term exposure to radiation, ecologists have found. The study is the first evidence that wild animals adapt to ionizing radiation, and the first to show that birds which produce most pheomelanin, a pigment in feathers, have greatest problems coping with radiation exposure.

A hawfinch (Coccothraustes coccothraustes) from the Chernobyl exclusion zone. This is one of several species bird species that appears to have adapted to radioactive conditions inside the Chernobyl Exclusion Zone.
Credit: Photo copyright T.A. Mousseau and A.P. Mřller, 2011

Birds in the exclusion zone around Chernobyl are adapting to -- and may even be benefiting from -- long-term exposure to radiation, ecologists have found. The study, published in the British Ecological Society's journal Functional Ecology, is the first evidence that wild animals adapt to ionizing radiation, and the first to show that birds which produce most pheomelanin, a pigment in feathers, have greatest problems coping with radiation exposure.

According to lead author Dr Ismael Galván of the Spanish National Research Council (CSIC): "Previous studies of wildlife at Chernobyl showed that chronic radiation exposure depleted antioxidants and increased oxidative damage. We found the opposite -- that antioxidant levels increased and oxidative stress decreased with increasing background radiation."

The Chernobyl disaster, which occurred on April 26 1986, had catastrophic environmental consequences. However, because it remains heavily contaminated by radiation, the region represents an accidental ecological experiment to study the effects of ionizing radiation on wild animals.

Laboratory experiments have shown that humans and other animals can adapt to radiation, and that prolonged exposure to low doses of radiation increases organisms' resistance to larger, subsequent doses. This adaptation, however, has never been seen outside the laboratory in wild populations.

Previous studies of the level of antioxidants and oxidative damage at Chernobyl are limited to humans, two bird species and one species of fish. Because different species vary widely in their susceptibility to radiation, this limited data has made it difficult to study how wild animals adapt to radiation exposure.

The researchers, including ecologists who have worked around Chernobyl since the 1990s, used mist nets to capture 152 birds from 16 different species at eight sites inside and close to the Chernobyl Exclusion Zone. They measured background radiation levels at each site, and took feather and blood samples before releasing the birds.

They then measured levels of glutathione (a key antioxidant), oxidative stress and DNA damage in the blood samples, and levels of melanin pigments in the feathers. Melanins are the most common animal pigments but because the production of pheomelanin (one type of melanin, the other type being eumelanin) uses up antioxidants, animals that produce the most pheomelanins are more susceptible to the effects of ionizing radiation.

As well as taking samples from 16 different bird species, the team used a novel approach to analyze their results. The method takes better account of how closely related different species are. This is important because some species are more susceptible to radiation than others. The method focuses the analysis on individual birds instead of species averages, making it a much more sensitive way to analyze biochemical responses to radiation.

The results revealed that with increasing background radiation, the birds' body condition and glutathione levels increased and oxidative stress and DNA damage decreased. They also showed that birds which produce larger amounts of pheomelanin and lower amounts of eumelanin pay a cost in terms of poorer body condition, decreased glutathione and increased oxidative stress and DNA damage.

"The findings are important because they tell us more about the different species' ability to adapt to environmental challenges such as Chernobyl and Fukushima," said Galván.

Levels of radiation in the study area ranged from 0.02 to 92.90 micro Sieverts per hour. The 16 bird species surveyed were: red-backed shrike; great tit; barn swallow; wood warbler; blackcap; whitethroat; barred warbler; tree pipit; chaffinch; hawfinch; mistle thrush; song thrush; blackbird; black redstart; robin and thrush nightingale.

Ionizing radiation damages cells by producing very reactive compounds known as free radicals. The body protects itself against free radicals using antioxidants, but if the level of antioxidants is too low, radiation produces oxidative stress and genetic damage, which leads to aging and death.

Ismael Galván, Andrea Bonisoli-Alquati, Shanna Jenkinson, Ghanem Ghanem, Kazumasa Wakamatsu, Timothy A. Mousseau and Anders P. Mřller (2014). "Chronic exposure to low-dose radiation at Chernobyl favors adaptation to oxidative stress," is published in Functional Ecology on Friday 25 April 2014.


Story Source:

The above story is based on materials provided by British Ecological Society (BES). Note: Materials may be edited for content and length.


Journal Reference:

  1. Ismael Galván, Andrea Bonisoli-Alquati, Shanna Jenkinson, Ghanem Ghanem, Kazumasa Wakamatsu, Timothy A. Mousseau, Anders P. Mřller. Chronic exposure to low-dose radiation at Chernobyl favors adaptation to oxidative stress in birds. Functional Ecology, 2014; DOI: 10.1111/1365-2435.12283

Cite This Page:

British Ecological Society (BES). "Chernobyl's birds adapting to ionizing radiation." ScienceDaily. ScienceDaily, 24 April 2014. <www.sciencedaily.com/releases/2014/04/140424223057.htm>.
British Ecological Society (BES). (2014, April 24). Chernobyl's birds adapting to ionizing radiation. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2014/04/140424223057.htm
British Ecological Society (BES). "Chernobyl's birds adapting to ionizing radiation." ScienceDaily. www.sciencedaily.com/releases/2014/04/140424223057.htm (accessed September 1, 2014).

Share This




More Plants & Animals News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) — A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) — An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) — In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) — State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) 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