Physiological ecology, senescence, stress physiology

Senescence, a decline in reproductive performance or survival with age, is predicted to occur because investment in traits such as growth and reproduction come at a cost to self-maintenance. Variation in longevity is influenced in part by genetic factors, but lifestyle is also likely to be very important. Stress is expected to accelerate senescence, yet the mechanisms linking variation in stress responsiveness and stress exposure and longevity are poorly understood. Our research takes an integrative, whole organism approach to the endocrine and cellular mechanisms of senescence within an evolutionary context. To date, we have focused on three inter-related questions in both captive and free-living bird populations:

1.     Does the stress response change with age?

2.     Does exposure to stress hormones during early life have long-term costs?

3.     Does exposure to stressors accelerate cellular and organismal senescence?

Understanding the mechanisms that lead to variation in lifespan and are influenced by exposure to environmental stressors has important implications for health and conservation. This is particularly true in light of environmental change and increasing human perturbation.