Thursday, 12 July 2007

Chernobyl radiations affects brightly coloured birds most

Studies on birds breeding in the forests around the Chernobyl nuclear plant have found that brightly coloured birds are among the species most adversely affected by the high levels of radiation.

Dr Anders Møller of the Université Pierre et Marie Curie and Professor Timothy Mousseau of the University of South Carolina examined 1,570 birds from 57 different species. They found that populations of certain 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.

Most interestingly these results have been linked to the role of antioxidants, those chemicals that help protect living organisms from the damaging effects of free radicals. Certain activities use up large amounts of antioxidants. These include producing carotenoid-based pigments for feathers, migrating long distances and laying large eggs. Møller and Mousseau hypothesized that birds with fewer antioxidants would be most adversely affected by exposure to radiation.

Among the brightly coloured species most affected were Golden Orioles, Blackbirds and Blue Tits, while drab species like Tree Pipits, Coal Tits and Chaffinches were much less affected. Long distance migrants that were most affected included Quails, Golden Orioles, Hoopoes, Blackbirds and Robins, while non-migrant or short-dispersing species like Great Tits, Coal Tits and Song Thrushes were much less affected.

A P Møller and T A Mousseau (2007). Determinants of interspecific variation in population declines of birds from exposure to radiation at Chernobyl. Journal of Applied Ecology, published online at

Photo: Great Tit at Chernobyl by Tim Mousseau