Scientists monitoring the area near the nuclear reactor in Chernobyl say they have found proof that several species of birds have developed a mechanism enabling them to adapt to the high level of radioactivity there. The researchers claim that the birds’ physical condition has also improved due to the mechanism they have developed since the accident at the site, 28 years ago last week.

The findings of the new study, conducted by Dr. Ismael Galvan of the Spanish National Research Council and published several days ago in the British Ecological Society’s journal Functional Ecology, were based on samples collected from 152 birds belonging to 16 species. The birds were collected in nets spread throughout the area and released once feather and blood samples were taken.

The nuclear accident at the reactor, located in Ukraine near the border with Belarus, released a tremendous amount of radiation into the environment. The surrounding area was evacuated, and entry is still restricted because of the high level of radiation there.

Researchers had previously showed that the radiation had harmed wild animal populations in the vicinity. In the recent study, the scientists examined birds, focusing mainly on their response to oxidative stress – one of the effects of exposure to ionizing radiation. Such exposure damages cellular structure and functioning in animals, including human beings, and causes genetic damage as well. In oxidative stress, free radicals are released into the body, which utilizes antioxidants to protect itself from them.

While laboratory studies have showed that humans and other animals can develop mechanisms which allow them to adapt to oxidative stress, no evidence of this phenomenon had been found in nature.

Examination of the birds at Chernobyl revealed that many had a higher level of a key antioxidant called glutiathone. The higher the level of radiation at the site where the birds were caught, the more glutiathone they had in their bodies. These birds also had lower levels of genetic damage, and their physical condition was better than birds with lower levels of glutiathone.

Among the birds studied were members of several species that are well known in Israel, including the great tit, the barn swallow, the blackbird, the European robin and the thrush nightingale.

In another interesting finding, birds at Chernobyl which had a higher level of pheomelanin – a kind of pigment – in their feathers displayed a lower level of antioxidants in their bodies, and their physical condition was not as good as those lacking the pigment. This is because the birds’ bodies use antioxidants to create the pheomelanin, so the antioxidants are not "available" to protect them.

The researchers believe their findings show that some of the birds living in proximity to Chernobyl have learned to adapt physiologically to radiation that is not at a deadly level, but is still much higher than the level that occurs naturally. Since almost 30 years have gone by since the incident there, the scientists believe the adaptive, genetic mechanism is already being passed on to new generations of birds that live in the area.

“The findings are important because they tell us more about the different species’ ability to adapt to environmental challenges such as Chernobyl and Fukushima,” Galvan said when the study was published.

He and his colleagues say that even if substantial damage was done to wildlife in the Chernobyl area, several species of animals have apparently managed to adapt to the new circumstances of life in surroundings still tainted by radiation.