Birds Adapt to Ionizing Radiation in Chernobyl

New research suggests that birds have adapted to, and perhaps benefitted from, the high ionizing radiation present around Chernobyl. This study is the first to show that wild animals can adapt to radiation, and provides an explanation for why certain bird species – those with feathers replete with a certain pigment – have had more trouble adapting to these hostile conditions.

The 1986 Chernobyl disaster wreaked havoc upon the environment and forced mass human evacuation from the accident zone. Nearly 30 years on, this catastrophic nuclear incident has also provided a natural experiment on the effects of ionizing radiation on wildlife. Laboratory studies have shown that animals can adapt to higher levels of radiation, but previous research in the wild was limited to a small group of species. This study investigated 152 birds of 16 different species (from great tit to blackbird) in and around the Chernobyl Exclusion zone, and revealed some surprising results.

Ionizing radiation damages cells by depleting antioxidants and causing DNA damage (which can lead to cancer). However, there is growing evidence that long-term exposure to low level radiation can increase resilience in animal species. The scientists demonstrated that high-level exposure to ionizing radiation was linked to healthy body condition, high antioxidant levels and low DNA damage in birds. Intriguingly, they also found that bird species with feathers rich in pheomelanin – a pigment which uses up protective anti-oxidants, thereby reducing the bird’s ability to deal with radiation – were significantly less healthy than others also exposed to high-level radiation.

While this study can only draw correlations between exposure and health, and further work is needed to establish causal relationships, it nonetheless provides intriguing insights into the impact of radiation on ecology and evolution.

The original paper can be found here: http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12283/abstract