Bird Island Diary — October 2009
October is ‘peak season’ for the flying-bird fieldwork team on Bird Island. Both Derren and Stacey have spent long days in the field monitoring the arrival of the black-browed and grey-headed albatrosses, and both species of giant petrel. By the end of the month, the grey-heads have finished laying their eggs, which will hatch around Christmas. The black-browed albatrosses arrive slightly later but seem to settle quicker than the grey-headed, which means both egg laying peaks come in fairly quick succession.
Our resident white-capped albatross has returned again. Normally resident on islands off the coast of New Zealand, he has bred with a female black-browed albatross on BI for the last three years. They have yet to raise a chick to fledging — perhaps 2009/10 will be the year that they are successful…
We had another uncommon vagrant this month — a pectoral sandpiper was spotted by Stacey amongst the gentoo penguins at Square Pond. An arctic-breeding species, pectoral sandpipers winter in South America, but occasionally get blown off course and end up in South Georgia. This was the first confirmed sighting on Bird Island for several years.
Stacey’s giant petrel round takes in a large area to the west of the base. Numbers of northern giant petrel nests this year are comparable to the number counted last year. By the end of the month, the southern species had begun to lay their eggs. Stacey also counted 4 hybrid pairs: where a male southern giant petrel breeds with a female of the northern species.
Light-mantled sooty albatrosses came back to Bird Island early this month. These biennial breeders nest on rocky ledges on cliffs, and their haunting display call can be heard all around the island on calm days. Pairs of birds fly together in a perfectly synchronous display flight — one of the most beautiful sights on our little island.
After an especially quiet winter for leopard seals at Bird Island, October has brought with it a good number of sightings. The majority of these sightings have been of one individual, a beautiful juvenile female animal who received the flipper tag W8362, and is now carrying a geolocator device. With some good fortune, she will return in one or two years, and a seal assistant of the future (as this will be beyond my tenure) will retrieve the device, to see where she has been in between visits to BI.
We had one southern elephant seal pup this year — Bird Island does not have any large breeding colonies of elephant seals as seen elsewhere on South Georgia, and numbers vary greatly between years. As this years pup was born close to base, we have been able to watch it grow, whilst its mother seemingly deflates, as all the fat-rich milk is transferred to her baby. After three weeks, she will return to sea and the pup will be left to fend for itself.
October also saw the end of winter for us in terms of personnel on base — Pharos SG called on October 5th, ending the tranquillity of winter by bringing with it Dirk (science coordinator) and Grant (electrical engineer) from Cambridge, who are visiting for a month, and a very welcome consignment of fresh fruit and vegetables! What a treat to have a salad, after the long months without fresh produce!
Derren Fox, Zoological Field Assistant.