Birds adapting to long-term radiation exposure at Chernobyl

No humans live in the 19-mile exclusion zone surrounding Chernobyl, the nuclear disaster which devastated the Ukrainian countryside in 1986, but as ecologists recently showcased, birds have slowly adapted to the area. To better understand how birds were coping with the region's dangerous radioactivity, researchers captured 152 birds of 16 species at various sites within Chernobyl's exclusion zone. The researchers collected feather and blood samples from captured birds. The samples were used to test for levels of glutathione, an antioxidant vital in protecting plants and animals against oxidative stress and DNA damage. Researchers also tested for levels of melanin pigments in the bird feathers. Pheomelanin, a certain type of melanin, depletes the body's antioxidant supply. Surprisingly, scientists found many birds had adapted to high levels of radiation by minimizing pheomelanin production and pumping out glutathione. Birds that had not initiated this adaptation showed visible signs of physical deterioration. "Previous studies of wildlife at Chernobyl showed that chronic radiation exposure depleted antioxidants and increased oxidative damage," Dr. Ismael Galván, of the Spanish National Research Council, told the International Business Times. "We found the opposite -- that antioxidant levels increased and oxidative stress decreased with increasing background radiation." The 16 species studied included: 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. "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. The study was published last week in the journal Functional Ecology.