Physiological adjustments to high foraging effort negatively affect fecundity but not final reproductive output in captive zebra finches [RESEARCH ARTICLE]

Kang Nian Yap, Donald R. Powers, Melissa L. Vermette, Olivia Hsin-I Tsai, and Tony D. Williams Foraging at elevated rates to provision offspring is thought to be an energetically costly activity and it has been suggested that there are potentially physiological costs associated with the high workload involved. However, for the most part evidence for costs of increased foraging and/or reproductive effort is weak. Furthermore, despite some experimental evidence demonstrating negative effects of increased foraging and parental effort, the physiological mechanisms underlying costs associated with high workload remain poorly understood. To examine how high workload affects hematology, oxidative stress and reproductive output, we experimentally manipulated foraging effort in captive zebra finches, Taeniopygia guttata, using a previously described technique, and allowed individuals to breed first in low foraging effort conditions, and then in high foraging effort conditions. We found that birds up-regulated hematocrit and hemoglobin in response to training. Birds subjected to increased workload during reproduction had lower fecundity, although final reproductive output was not significantly different than that of controls. Offspring of parents subjected to high workload during reproduction also had higher oxidative stress when they were 90 d of age. Total antioxidant capacity and reactive oxygen metabolites of birds responded differently in the two breeding attempts, but we did dete...
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research