FREE BIRD

We propose to investigate the physiological, behavioural, and fitness effects of chronic exposure to ionizing radiation from the Fukushima nuclear disaster in wild birds from Japan. We will also investigate theoretically the predicted consequences of such effects on the population dynamics of the study species, combining radiotoxic effects at (sub)individual levels observed along the gradient of exposure in the Fukushima area and population modelling based on species life-history traits. This project will be devoted to 3 bird species, which vary in their reproductive physiology and behavioural ecology. It will use a sampling strategy along a gradient of radiological exposure within the 100-km area, during two major periods: the first plumage molt after the accident and the next breeding period. We will focus on the effects of radiation exposure on sexual signal expression and reproductive investment in wild birds, by tracking several key physiological factors (e.g. hormone levels, immunity, oxidative stress, genotoxicity and sperm quality). As such, the results will allow us to understand how radiation exposure affects resource allocation (e.g., pigments, antioxidants) between processes linked to survival (immunity, oxidative stress) or reproduction (elaboration of sexual signals, reproductive investment). Finally, we expect to produce a new set of data on ionising radiation effects in wildlife (birds) realistically exposed under contaminated field conditions. These data will represent a major contribution to be tested against the current ecological protection criteria, those latter being mainly based on data acquired under controlled laboratory conditions. Moreover this project will undoubtedly give new robust knowledge concerning the controversial findings about the ecological consequences of chronic radiation exposure still existing 25 years after the Chernobyl accident.