The distribution and abundance of burrowing sea birds procellariiformes at bird island south georgia south atlantic 1. introduction and methods
Hunter, I.; Croxall, J.P.; Prince, P.A.
British Antarctic Survey Bulletin 56: 49-68
The habitats utilized by burrowing petrels at Bird Island, South Georgia, are described and the habitat modification induced by the activities of fur seals and other seabirds summarized. The field methods for an investigation of the distribution and abundance of the 9 spp. of burrow-dwelling petrels [dove prion (Pachyptila desolata), fairy prion (P. turtur), blue petrel (Halobaena caerulea), white-chinned petrel (Procellaria aequinoctialis), South Georgia diving petrel (Pelecanoides georgicus), common diving petrel (P. urinatrix exsul), Wilson's storm petrel (Oceanites oceanicus), black-bellied storm petrel (Fregetta tropica) and gray-backed storm petrel (Garrodia nereis)] that breed on Bird Island are described in detail. About 40% of the 200 ha of ground suitable for burrow excavation was investigated by means of a system of grid squares each 3600 m2 in area. In each square, 2 randomly located circular quadrats of area 36 m2 were studied. For each quadrat, aspect, slope, vegetation types and their cover, extent of fur seal influence and status of every burrow were recorded. Seven categories of empty and occupied burrows were recognized. Examination techniques (including use of tape-recorded calls to facilitate species identification) are described in detail. Over 5000 burrows were examined, with dove prion the most abundant species.