Southern Giant Petrels doing well on Gough Island

With attacks by introduced House Mice Mus musculus killing a large proportion of Tristan Albatross chicks Diomedea dabbenena (and Atlantic Petrel chicks Pterodroma incerta), it is pleasing to report that the population of at least one ACAP-listed species appears to be remaining stable on Gough Island in the South Atlantic.

Gough is the most northerly extant breeding locality for Southern Giant Petrels Macronectes giganteus (the species went extinct on Tristan during the 19th century).  In 2001/02, the population was estimated as 225-245 annually-breeding pairs (Cuthbert & Sommer 2004). See also the ACAP Species Assessment at http://www.acap.aq/acap-species.

Southern_Giant_Petrel_Gough_Island_by_John_Cooper

During September 2009 all known colonies at four main localities on the island were visited during the incubation period, yielding a total count of 317 pairs.  The difference between this and the published account is thought largely due to the discovery of a breeding colony on the west coast side of the island in 2005/06.

Southern_Giant_Petrel_colony_Gough_Island_by_John_Cooper

At the largest colony, below Low Hump, breeding birds have been banded opportunistically since the 1980s. A check of incubating birds on 28 September 2009 retrapped 54 banded birds. In addition, 13 GLS loggers (of 20 deployed the previous season) have been recovered so far from incubating birds at the Low Hump colony, that will yield information on where the birds went away from the island over a year's period.

CUTHBERT, R.J. & SOMMER, E.S. 2004. Population size and trends of four globally threatened seabirds at Gough Island, South Atlantic Ocean. Marine Ornithology 32: 97-103. http://www.marineornithology.org/PDF/32_1/32_1_97-103.pdf.

John Cooper, ACAP Information Officer, Marthán Bester, University of Pretoria, and Peter Ryan, University of Cape Town, 04 October 2009

 

The Agreement on the
Conservation of Albatrosses and Petrels

ACAP is a multilateral agreement which seeks to conserve listed albatrosses, petrels and shearwaters by coordinating international activity to mitigate known threats to their populations.

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