Chornobyl's songbirds: Adapting to life in a nuclear zone

Finnish scientists have studied birds living in the exclusion zone around the Chornobyl Nuclear Power Plant. For generations, the birds were subjected to a radiation-exposed environment. Although the radiological contamination has not decimated the population, it has led to numerous changes in their bodies.

Great tits are one of the many species of songbirds inhabiting the Chornobyl zone. In the area around the Chornobyl Nuclear Power Plant, abandoned by humans after the disaster 38 years ago, nature is flourishing wonderfully. The area of about 2,600 square kilometres has become an enclave inaccessible to humans, where diverse flora and fauna thrive without human interference.

The Chernobyl zone fascinates scientists. Although the war in Ukraine has hindered research in the past two years, some teams still undertake new research projects.

Recently, experts from the Finnish University of Jyväskylä studied songbirds' reproductive behaviours and early life stages growing up in radiologically contaminated habitats. The team investigated how the radiation-exposed environment affects two common species of European songbirds: the great tit (Parus major) and the collared flycatcher (Ficedula hypoleuca).

Several nesting boxes were placed in two regions, one with high radiological contamination and the other with relatively low contamination. A series of tests was used to compare the bird families.

Scientists examined the diet and gut microbiomes of bird populations. Such comparative tests were conducted for the first time since the biggest disaster in the history of nuclear energy and one of the most significant industrial disasters of the 20th century.

It occurred during the night of 25 to 26 April 1986. The reactor core overheated in the nuclear reactor of power block No. 4 of the Chornobyl Nuclear Power Plant, causing a hydrogen explosion. Radioactive substances spread, and people had to leave the area forever as it was no longer habitable.

However, animals remained in the high radiation area. It turns out that despite the conditions, nature is doing well. Many species live here, including moose, bears, deer, lynxes, wolves, and Przewalski's horses.

Sameli Piirto, a doctoral candidate at the University of Jyväskylä, claims that radiological contamination has consequences for organisms at an early stage of life. However, the changes that occur due to their impact on subsequent generations of animal populations are not yet fully understood.

Scientists determined that although birds occupied fewer nests in heavily contaminated areas, there were no significant differences in reproductive ecology or the health of chicks from "clean" and contaminated areas. However, radiation has indeed changed the lives of the birds.

Bird species living near Chornobyl have smaller heads and brains. It is unknown whether this affects their cognitive abilities.

Finnish research on birds did not show the harm suffered by this species of fauna in the long term by the human population, which was quickly evacuated from the contaminated lands. From the Chornobyl zone, designated not only in today's Ukraine but also partially in Belarus and Russia, 35 thousand people had to move out.

Radiation after the disaster increased the risk of cancer. The accident and the displacement of many residents resulted in trauma, depression, alcoholism, and other mental illnesses.