Agreement on the Conservation of Albatrosses and Petrels

Population modelling of Gough Island’s Atlantic Yellow-nosed Albatrosses

Sarah Converse (US Geological SurveyPatuxent Wildlife Research Center, Maryland, USA) gave a co-authored oral presentation at this year’s North American Ornithological Conference, held in Washington, D.C., USA over 16-20 August on modelling population data collected over several decades on Atlantic Yellow-nosed Albatrosses Thalassarche chlororhynchos breeding on Gough Island.

The talk’s abstract follows:

“Integrated population models (IPM) represent a major advance in our potential to understand population dynamics.  However, species with complex life histories pose special challenges.  We developed an IPM for Atlantic Yellow-nosed Albatross (Thalassarche chlororhynchos) on Gough Island based on a 34-year dataset.  The base of the IPM is a multi-event mark-recapture model which accounts for multiple observable and partially-unobservable latent states.  The multi-event model is combined with nesting colony counts to form the IPM.  We describe the challenges that existed in developing this model, including pre-breeding and skipped breeding periods where birds are unobservable, and breeding colony immigration.  We correlated posterior distributions for the parameters of interest to population growth rates. Variation in growth rate was most strongly correlated with immature survival, suggesting that factors at sea could be driving population trend.  Further IPM methods development, and more applications, are needed for species with complex life histories.”

 

Atlantic Yellow-nosed Albatross, photograph by Peter Ryan

Reference:

Converse, S.J.,Horswill, C., Cuthbert, R.KJ., Oppel, A., Bond, A.L., Cooper, J. & Ryan, P.G. 2016.  Integrated population modeling for species with complex life histories: application to Atlantic Yellow-nosed Albatross. In: NAOC VI, North American Ornithological Conference. Bringing Science & Conservation Together.  Abstracts.  16-20 August; Washington, DC, USA.  pp. 86-87.

John Cooper, ACAP Information Officer, 25 August 2016

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