Meeting Abstract
Urbanisation is expanding across the globe, and with urbanisation comes a long list of environmental challenges that birds either need to deal with or flee from. These challenges are for example increased air pollution, human disturbances, along with habitat fragmentation. Many species completely disappear from the urban landscape, whereas other species stay or even move into the new urban environment. But how well do they actually cope with the urban environmental stressors? Is urban life associated with hidden physiological costs? Or are their physiological systems efficient in protecting them from these multiple external stress factors? Previous studies have shown that air pollution triggers the antioxidant defences of most animals. However, the magnitude of the response and consequently, the physiological damages seem to be species, life-stage and context-specific. In addition, the links between physiological markers and survival are rarely investigated. Here we use a cross-fostering design to, first, disentangle genetic effects from direct environmental influences on oxidative stress physiology during postnatal development, a life-stage known to be sensitive to external stress. Using urban and rural nest box populations of great tits (Parus major), half-broods were swapped (day 3) between the environments and blood-sampled at day 15. Secondly, we examined whether oxidative stress status predicts survival to the subsequent breeding season and whether the relationship differed between habitats. We discuss the capacity of avian physiological systems to cope with urban environmental stress and the associated costs of being reared in the city.
