Event:

Even before it is born the conditions an animal experiences can have profound long-term effects on its health and wellbeing. In birds, mothers deposit a range of nutritional and hormonal factors into the egg that can alter embryonic development. If the mother experiences stress during egg laying a higher level of stress hormones are deposited into the egg, which can alter the development of the neuroendocrine system then controls the ability to respond to stress. In later life adults exposed to pre-natal stress have been shown to exhibit altered stress responses, fear-related behaviours and there is very good evidence that they are more likely to develop negative health issues. Work carried out by myself and colleagues suggests that in ovo conditions can program later behaviours via neuroendocrine systems and that these conditions may act as a signal to the offspring to alter development in such a way as to maximise survival in the post-natal environment, but that that there will also be costs associated with this strategy. However, oviparous species are often also exposed to many external factors as well, without the buffer of the maternal body as in mammals. The fact that birds use acoustic calls to communicate in many different contexts, such as calling to chicks or alarm calls when stressed, suggests that these calls can provide salient cues as to the quality of the environment. However, whether they provide such cues to embryos is unknown. We still have much to learn about the importance of different types of acoustic stimuli in shaping later phenotypes. Here I will detail some of the new experiments going on in my lab to investigate the adaptive significance of pre-natal acoustic stimuli. I will suggest that we should consider both in ovo and external stimuli as programming factors and work is now needed to integrate the two stimuli types to determine if re-programming of embryonic phenotypes is possible when environmental conditions change over the incubation period.