title: Protracted treatment with corticosterone reduces breeding success in a long-lived bird.
abstract: Determining the physiological mechanisms underpinning life-history decisions is essential for understanding the constraints under which life-history strategies can evolve. In long-lived species, where the residual reproductive value of breeders is high, adult survival is a key contributor to lifetime reproductive success. We therefore expect that when adult survival is compromised during reproduction, mechanisms will evolve to redirect resources away from reproduction, with implications for reproductive hormones, adult body mass, nest attendance behaviour and breeding success. We investigated whether manipulating corticosterone, to simulate exposure to an environmental stressor, affected the secretion of prolactin and breeding success in the black-legged kittiwake Rissa tridactyla. We used implanted Alzet® osmotic pumps to administer corticosterone to incubating kittiwakes at a constant rate over a period of approximately 8days. Manipulated birds were compared with sham implanted birds and control birds, which had no implants. There was no significant difference in the body mass of captured individuals at the time of implantation and implant removal. Corticosterone-implanted males showed lower nest attendance during the chick rearing period compared to sham-implanted males; the opposite pattern was found in females. Corticosterone treated birds showed a marginally significant reduction in breeding success compared to sham-implanted individuals, with all failures occurring at least 1week after implant removal. However, prolactin concentrations at implant removal were not significantly different from initial values. We were unable to measure the profile of change in corticosterone during the experiment. However, our results suggest a delayed effect of elevated corticosterone on breeding success rather than an immediate suppression of prolactin concentrations causing premature failure.
authors.affiliation: Centre for Ecology & Hydrology, Bush Estate, Penicuik EH26 0QB, United Kingdom.
authors.forename: Bethany F
authors.initials: BF
authors.lastname: Nelson
authors.affiliation: Centre for Ecology & Hydrology, Bush Estate, Penicuik EH26 0QB, United Kingdom.
authors.forename: Francis
authors.initials: F
authors.lastname: Daunt
authors.affiliation: University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, United Kingdom.
authors.forename: Pat
authors.initials: P
authors.lastname: Monaghan
authors.affiliation: Centre for Ecology & Hydrology, Bush Estate, Penicuik EH26 0QB, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: Wanless
authors.affiliation: Biomathematics & Statistics Scotland, JCMB, King's Buildings, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: Adam
authors.initials: A
authors.lastname: Butler
authors.affiliation: University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, United Kingdom.
authors.forename: Britt J
authors.initials: BJ
authors.lastname: Heidinger
authors.affiliation: Centre for Ecology & Hydrology, Bush Estate, Penicuik EH26 0QB, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Newell
authors.affiliation: Centre for Ecology & Hydrology, Bush Estate, Penicuik EH26 0QB, United Kingdom. Electronic address: asda@ceh.ac.uk.
authors.forename: Alistair
authors.initials: A
authors.lastname: Dawson
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D046091:Charadriiformes / Q000097:blood / Q000502:physiology*; D003345:Corticosterone / Q000008:administration & dosage* / Q000097:blood; D005260:Female; D007260:Infusion Pumps; D008136:Longevity; D008297:Male; D009425:Nesting Behavior / Q000187:drug effects; D011388:Prolactin / Q000097:blood / Q000378:metabolism; D012098:Reproduction / Q000187:drug effects* / Q000502:physiology; D012737:Sex Factors
chemical_list: D011388:Prolactin; D003345:Corticosterone
keywords: Black-legged kittiwake; Parental care; Physiology; Prolactin; Reproduction; Rissa tridactyla