Colorful birds fared worse after Chernobyl nuclear accident
Colorful birds fared worse than birds that used fewer antioxidants
Antioxidant use helped some birds after Chernobyl nuclear accident
mongabay.com
July 11, 2007
Brightly colored birds were more adversely affected by high levels of radiation around the Chernobyl nuclear plant, reports a study published online in the British Ecological Society’s Journal of Applied Ecology.
Examining 1,570 birds representing 57 species in the forests around Chernobyl, Anders Møller of the Université Pierre et Marie Curie and Timothy Mousseau of the University of South Carolina found that “populations of four groups of birds — those whose red, yellow and orange plumage is based on carotenoids, those that laid the biggest eggs, and those that migrated or dispersed the furthest — declined more than other species.”
The results suggest that antioxidants play an important role is fending off some of the harmful effects of free radicals.
“Certain activities use up large amounts of antioxidants,” explained a summary from Blackwell Publishing, publisher of Journal of Applied Ecology. “These include producing carotenoid-based pigments for feathers, migrating long distances and laying large eggs (birds lay down antioxidants in their eggs, and will deposit larger amounts of antioxidants in larger eggs). Møller and Mousseau hypothesized that because they had fewer antioxidants left to mop up dangerous free radicals, these birds would most adversely affected by exposure to radiation around Chernobyl.”
“We found that bird species differed in their response to radiation from Chernobyl,” wrote the authors. “The strongest declines in population density with radiation level were found for species with carotenoid-based plumage, long-distance migration and dispersal, and large eggs for their body size. All four of these factors are associated with antioxidant levels, suggesting that reduced antioxidant levels may cause population declines when species are exposed to radiation.”
“This is the first study linking the effects of radiation on population size of different species to antioxidant defence. Although all species must cope with the potentially detrimental effects of free radicals, because of their use of antioxidants, certain species are predisposed to suffer most from these negative effects,” they continued.
“There is large variation in natural levels of radioactivity due to differences in the abundance of radioactive isotopes, mainly in mountain regions where the underlying rock reaches the surface. There are no studies of the biological consequences of such variation in natural levels of radioactivity, but we suggest that some of the consequences can be predicted from the present study.”
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Chernobyl environment and people recovering. Chernobyl’s ecosystems seem to be recovering just 19 years after the region was badly contaminated with radiation from a nuclear meltdown according to a report backed by the United Nations. The report, “Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts,” says 4,000 deaths will probably be attributable to the accident ultimately – far less than the tens of thousands predicted at the time of the accident. Meanwhile, researchers say that biodiversity around the doomed plant is actually higher than before the disaster.