| Summary: | International audience 1. In many vertebrates, reproductive performance increases with advancing age but mechanics involved in such a pattern remain poorly studied. One potential mechanism may be the hormonal stress reponse, wich shifts enhergy investment away from reproduction and redicrects it towards survivals. In birds, this stress response is achieved through a release of corticosterone and is also accompanied by a decrease in circulating prolactin, a hormone involved widely in regulating parental cares. 2. It has been predicted that, when the value of the current reproduction is high relative to the value of future reproduction and survival, as it is expected to be in older adults, the stress response should be attenuated to ensure that reproduction is not inhibited. 3. We tested this hypothesis by measuring the corticosterone and prolactin responses of know age-age (8-36 years old) incubating snow petrels (pagadroma nivea) to a standardized capture/handling stress protocol. We also investigated whether an attenuation of the stress responses will correlate with a lower occurence of egg neglect, a frequently observed behavior in snow petrels.
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