Speciation and population differentiation in yellow-nosed albatrosses

Abstract

**Abstract:** The two species of yellow-nosed albatross, Atlantic (Thalassarche chlororhynchos) and Indian (Thalassarche carteri), are morphologically similar, however, they show some differences in behaviour and breeding range. We studied genetic variation within and among the two species using nuclear (microsatellite, Pema7 and Occa9) and mitochondrial (control region) markers. We analysed 201 samples of Atlantic yellow-nosed albatross from Nightingale, Inaccessible and Gough Islands and 33 samples of Indian yellow-nosed albatross from Amsterdam Island. Both sets of markers differentiated the two species. Microsatellite and Occa9 nuclear markers revealed two genetically distinct groups within Atlantic yellow-nosed albatross, grouping birds from Nightingale and Inaccessible Islands together and separating birds from Gough Island. Differences in at-sea distribution might have resulted in genetic differentiation within Atlantic yellow-nosed albatross, but there is no evidence currently of such differences. Both species are listed as endangered due to their limited number of breeding sites and threats from introduced diseases, introduced predators and fishing mortality. Our results contribute to conservation and management plans for the two species, and suggest the need for separate management of the two genetically distinct groups of Atlantic yellow-nosed albatross breeding at the Tristan group (80%) and Gough Island (20%). Key words: yellow-nosed albatross, genetic variation, microsatellite, nuclear marker **Authors:** Dilini Abeyrama¹, Zach Dempsey¹, Peter Ryan², Theresa Burg¹ ¹University of Lethbridge, ²FitzPatrick Institute of African Ornithology