London, Feb 6 (ANI): A team of researchers has discovered that birds living around the site of the Chernobyl nuclear accident have 5 percent smaller brains, an effect directly linked to lingering background radiation.
The finding is based on a study of 550 birds belonging to 48 different species living in the region, reports the BBC.
Brain size was significantly smaller in yearlings compared to older birds.Smaller brain sizes are thought to be linked to reduced cognitive ability.
In the study, scientists from Norway, France and the US, led by Professor Timothy Mousseau from the University of South Carolina, US, and Dr Anders Moller from the University of Paris-Sud, France, used mist nets to collect birds from eight woodland sites around Chernobyl, which have seen a decline in the numbers of larger animals and small invertebrates living within.
After controlling for the differences between species, they found that the birds had brains 5 percent smaller on average compared to birds not exposed to background radiation.
The effect was most pronounced in younger birds, particularly those less than a year old.
That suggests that many bird embryos did not survive at all, due the negative effects of their developing brain.
Stressed birds are able to change the size of some of their organs in order to tough out difficult environmental conditions.
For example, migrating birds that have travelled long distances often shrink certain organs as they use up energy.
But the brain is the last organ to be sacrificed in this way, say the researchers.
That suggests the background radiation could be having an even more pronounced effect on other organs within the birds.
It is unclear exactly what mechanism is shrinking the birds' brains.
The study has been published in the journal PLoS One. (ANI)