Meeting Abstract
Developmental rates are now known to have defining phenotypic consequences in adulthood, leading to a need for a greater understanding of the factors affecting such rates. While measuring such rates in neonates is relatively straight-forward, we have a relatively poor understanding of the factors affecting developmental rates pre-birth. Here we investigate the factors affecting heart rate, a known associate of developmental rates, in artificially-incubated eggs of the chestnut-crowned babbler (Pomatostomus ruficeps), a 50g avian cooperative breeder from outback Australia. As expected, heart rates were profoundly influenced by egg-shell temperature, and to a lesser extent embryo age. However, such effects were also modified by egg volume and laying order, suggesting maternal effects have a significant influence on embryo metabolic rates. Further, we found significant temperature-mediated plasticity on heart rates, which varied among individuals. Finally, we will investigate what factors may explain that variation in plasticity of heart rate among individuals.