Manipulation of Heat Dissipation Capacity Affects Avian Reproductive Performance and Output

Animal life requires hard work but the ability to endure such workload appears be limited. Heat dissipation limit (HDL) hypothesis proposes that capacity dissipate excess of body heat during may sustained energy use. Experimental facilitations loss rate via feather-clipping in free-living birds seem support HDL testing through laboratory experiments under controlled conditions is not reported. We employed a two-factorial experimental design test by manipulating exposure captive zebra finches ( Taeniopygia guttata ) cold and warm ambient temperature (14°C 25°C), manipulation insulating layer feathers around brood patch females (clipped unclipped). To simulate foraging costs encountered wild we induced effort employing feeding system necessitated hovering access food, which increased energetic reproduction despite ad libitum captivity. quantified outcome reproductive performance at level both parents, females, offspring. Thermal limitations due appeared beginning for parents with lower egg-laying success, smaller clutch size egg mass, compared cold. After hatching, an enhanced revealed higher mass unclipped these clipped also raised heavier bigger nestlings. Higher levels oxidative stress plasma were detected prior than However, biomarkers mothers neither affected nor activities. document upregulation antioxidant seems prevent possibly cost female condition offspring growth. Our study on laboratory-controlled corroborates evidence line hypothesis. The link between temperature-constrained output terms quality quantity particular interest light current climate change, illustrates emerging risks avian populations.