Reproductive ageing in three species of southern albatrosses

Hannah Froy (Institute of Evolutionary Biology, University of Edinburgh, Scotland, UK) and colleagues have published in the Journal of Animal Ecology on ageing effects in Black-browed Thalassarche melanophris, grey-headed T. chrysostoma and Wandering Diomedea exulans Albatrosses.

The paper’s abstract follows:

1. “Age-related variation in reproductive performance is ubiquitous in wild vertebrate populations and has important consequences for population and evolutionary dynamics.
2. The ageing trajectory is shaped by both within-individual processes, such as improvement and senescence, and the among-individual effects of selective appearance and disappearance. To date, few studies have compared the role of these different drivers among species or populations.
3. In this study, we use nearly 40 years of longitudinal monitoring data to contrast the within- and among-individual processes contributing to the reproductive ageing patterns in three albatross species (two biennial and one annual breeder) and test whether these can be explained by differences in life histories.
4. Early-life performance in all species increased with age and was predominantly influenced by within-individual improvements. However, reproductive senescence was detected in only two of the species. In the species exhibiting senescent declines, we also detected a terminal improvement in breeding success. This is suggestive of a trade-off between reproduction and survival, which was supported by evidence of selective disappearance of good breeders.
5. We demonstrate that comparisons of closely related species which differ in specific aspects of their life history can shed light on the ecological and evolutionary forces shaping variation in ageing patterns.“

Grey-headed Albatross at Bird island, photograph by Richard Phillips

Reference:

Froy, H., Lewis, S., Nussey, D.H., Wood, A.G. & Phillips, R.A. 2017. Contrasting drivers of reproductive ageing in albatrosses. Journal of Animal Ecology 86:1022–1032. DOI: 10.1111/1365-2656.12712.

John Cooper, ACAP information Officer, 18 August 2017