News from the field: working with Southern Giant Petrels on Gough Island

Graham Parker and Kalinka Rexer-Huber, originally from New Zealand, are spending a year on Gough Island in the South Atlantic conducting research towards the eventual eradication of the introduced House Mouse - which notoriously attacks Tristan Albatross Diomedea dabbenena chicks.  They are also taking the opportunity to study other ACAP-listed species as they report below:

"The last couple of months we have had the pleasure of working with Southern Giant Petrels Macronectes giganteus here on Gough Island.  Largest of the Procellariidae petrels, Southern Giant Petrels on the wing are easily confused with Northern Giant Petrels M. halli.  Adults of the two species are reliably distinguished by having different coloured bill tips; greenish for Southern and reddish for Northern.

Giant petrels have a somewhat fearsome reputation, being large and very capable predators as well as scavengers of carrion.  They are frequently referred to as being quite an unattractive seabird, in part because of the massive bill, characteristic smell and somewhat hair-raising braying call.  Southern Giant Petrels on Gough nest colonially at three wet heath sites, with a few pairs also breeding on an east coast beach.  The colony we worked in, above the western cliffs of Gough, is separated into three distinct sub-colonies over quite a large area.  The surrounding vegetation is predominantly tall bog ferns Blechnum palmiforme and large Spartina arundinacea tussocks, with giant petrel nests scattered throughout.

Our work was to assist in establishing a new long-term study at the most accessible colony.  We did a thorough count of incubating birds, returned to count nestlings shortly after hatching, then returned again to band all the chicks.  Many of the parents were still brooding when we banded the downy chicks.  Although our presence in the colony certainly caused some comment among both nesting and loafing birds, we were very surprised at the lack of aggression from brooding parents when we banded their chicks.  We initially put on leather gloves and prepared ourselves for some not insignificant nips from the large and strong bills of the giant petrel parents. 

However, we soon found that we could safely pull a chick leg out from under the pile of down and feathers and quickly band it under its parent without gloves.  Most brooding birds simply watched the process, their eyes following us intently, while others took a more active role in nibbling gently at our hands.  The chicks were often less relaxed than their parents - a few defended themselves with squeaky braying calls and by regurgitating stomach oil onto us.  Fortunately though not too many of the chicks wasted their valuable calories in this way."

In September 2010 when the annual relief of the island's South African weather station takes place it is intended to commence colour-banding the adults and staking each nest.  Kalinka and Graham's welcome efforts have meant the planned new demographic study is getting a good head start.  It is significant that the Southern Giant Petrels of Gough are so amenable to study in this way.  This is not the case at many, if not most, other breeding sites.

Graham's and Kalinka's research on Gough is managed by the Royal Society for the Protection of Birds, funded by the UK's Overseas Territories Environment Programme, supported logistically by the South African Department of Environmental Affairs and conducted under permit from the  Conservation Department of Tristan da Cunha.

Click here for an earlier ACAP news item on Gough's giant petrels.

John Cooper, ACAP Information Officer and Graham Parker & Kalinka Rexer-Huber, Royal Society for the Protection of Birds, 6 January 2010

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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