Avian developmental programming: the chicken and the egg

Prenatal sensory development, which occurs across broad taxonomic groups, means that at emergence animals arrive with expectations about the world in which they will live. The resulting adaptive physiological responses potentially promote both their growth and survival. My research focuses on the impact of early life events – both before and after hatching - on avian growth, development, physiology and ultimately on their fitness. I use a range of avian species to understand the impact of early life experiences in driving sensory development and the impacts of early life stress, within and across generations. Focusing on zebra finches, we have quantified the impact of parental stress, embryonic heat stress and anthropogenic noise on individual development. More recently we have examined how avian embryos respond to the predictable circadian cycles of light and temperature and the potential consequences for posthatch timing, growth and welfare. Our recent data suggest that the avian clock starts well before hatching and may drive a range of developmental and metabolic processes. These fascinating insights have demonstrated that avian embryos are far from passive agents in their own developmental processes, but have subtle sensory capacities which can best direct their development for optimal outcomes. Our findings have also equipped us with indications of how birds are likely to respond in a changing world and the mechanisms which offer most plasticity in their responses.