A blurring of life-history lines: Immune function, molt and reproduction in a highly stable environment.

摘要: Rufous-collared sparrows (Zonotrichia capensis peruviensis) from valleys in the Atacama Desert of Chile, live an extremely stable environment, and exhibit overlap molt reproduction, with valley-specific differences proportion birds engaged both. To better understand mechanistic pathways underlying timing life-history transitions, we examined relationships among baseline stress-induced levels corticosterone (CORT), testosterone, bacteria-killing ability blood plasma (BKA), as well haemosporidian parasite infections genetic structure two groups separate over course a year. Birds neither molting nor breeding had lowest BKA, but there were no other three categories molt-reproductive stage. BKA varied year, May/June exhibiting significantly lower than rest We also documented direction relationship between CORT at different times during The these coincides some trends reproductive stage, differs enough to indicate that individual-level plasticity, or population-level variability, coordinating hypothalamo-pituitary-adrenal axis activity found weak preliminary evidence for differentiation populations, not isolation. No infected haemosporidia, which may be indicative reduced pressure deserts. data suggest trade off components, rather are able invest multiple components based on their condition.