Differences in oxidative stress across seasons and ability to cope with environmental mismatch in muscle and brain of black-capped chickadees (Poecile atricapillus) and rock pigeons (Columba livia)

Resident birds in temperate areas respond to seasonally fluctuating temperatures by adjusting their physiology so as to match thermogenic requirements of their environment. Climate change is predicted to increase the frequency of heat waves, increasing the likelihood that birds will face environmental mismatch. Changes in BMR due to seasonality or anomaly events should show effects to the oxidative stress system. We examined the effects of chronic and acute heat exposure on muscle and brain tissue total antioxidant capacity, enzymatic activities of catalase (CAT), and glutathione peroxidase (GPx) and lipid peroxidation (LPO) damage in two temperate bird species of differing body masses and ecological strategies, the black-capped chickadee (Poecile atricapillus) and the rock pigeon (Columba livia), across three seasons. We found that heat stress did not alter oxidative stress in either species or tissue. But, in muscle, rock pigeons and black-capped chickadees demonstrated similar season...