“The return of the King and the growth of the gentoo, new data on penguins nesting in Tierra del Fuego”.

A SCHIAVINI; N GOODALL; A RAYA REY; L BENEGAS

Ushuaia, Tierra del Fuego, Argentina

Conferencia; V International Penguin Conference; 2004

CADIC- CONICET

King penguins were known to nest at Staten Island (Tierra del Fuego). One of the known breeding localities was Puerto Roca, where hunters reported about 20,000 pairs in 1869. By the early XX century the colony disappeared due to hunting. We recorded birds in the coasts of Staten Island in five occasions from 1992 to 2003. Birds are also known to visit Isla Martillo (Beagle Channel) to moult in numbers from one to three on every summer. On 9th January 2004 we recorded three animals on Puerto Roca. One of them was incubating an egg, in the same exact location reported for the colony during the XIX century. We did not verify the viability of this egg later in the season. If a chick was raised it would have represented the return of king penguins to Staten Island after 94 years. Reports of gentoo penguins from the Tierra del Fuego archipelago are scarce. Despite of some sightings in the Cape Horn area, no breeding record existed for the area. Gentoo penguins were reported to visit and nest on Isla Martillo since the 1980´s. The colony is located within a Magellanic penguin colony, and showed an increase in numbers of active nests, from one (December 1992 and December 1993), to five (November 2000), eight (November 2002) and nine (November 2003). Isla Martillo represents the only known breeding ground for gentoo penguins in South America. We found no evidence of gentoo penguins nesting or visiting Staten Island despite intensive surveys. The growth of the gentoo penguin colony from Isla Martillo may be the result of the recruitment of birds descendent of the first settlers or to movements of animals from the Falkland (Malvinas) Islands (or both factors acting together). Also, we propose that the vast fuegian archipelago may hide unknown breeding locations for gentoo penguins, to be revealed in the future.