Researchers studying birds near the Chernobyl nuclear-disaster site in Ukraine have found the first evidence of wild animals adapting to ionizing radiation.

Ismael Galván, now at the Doñana Biological Station in Seville, Spain, and his colleagues examined feather and blood samples from 16 bird species, including barn swallows (Hirundo rustica) and wood warblers (Phylloscopus sibilatrix), in and around the Chernobyl exclusion zone.

They found that birds from more-contaminated areas had higher levels of antioxidants — which mop up damaging free radicals produced by radiation exposure — than birds from areas that were less contaminated. Animals from high-radiation regions also had better body condition and showed decreased DNA damage and oxidative stress.

Funct. Ecol. (2014)