CESIMAR - CENPAT   25625
CENTRO PARA EL ESTUDIO DE SISTEMAS MARINOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Breeding performance of a new King Penguin colony in the Strait of Magellan, Chile.
Autor/es:
GARCÍA BORBOROGLU, PABLO; GODOY, CLAUDIA; MUNOZ, LUIS
Lugar:
Cape Town
Reunión:
Congreso; 9th International Penguin Congress; 2016
Resumen:
King penguins breed on sub-Antarctic islands between latitude 45° south and 55° south. Their populations have increased since the end of the last century following a drastic decline during the 19th and the beginning of the 20th century, but recent surveys also indicate that several large colonies have stabilized or decreased. More king penguins had been prospecting and visiting the coasts of Tierra del Fuego, southern Patagonia, to molt, and breeding was anticipated. A new King penguin colony was established at Bahía Inútil (53 27?42.11S, 69 18?32.42W), a bay to the east of the Magellan Strait, Chile during the 2009-2010 breeding season. Archaeological records indicate that local aboriginal groups used penguins as a source of food and material to make tools and weapons thousands of years ago. Since 2014 we are conducting a research and monitoring program to follow the evolution of this new colony, estimating breeding and non-breeding population size fluctuations, breeding phenology, breeding parameters and to determine chick mortality causes. Population size ranged from 20 in July to 160 individuals in November of 2015, where 40% of them were incubating. Compared to original reports, the number of breeders with eggs increased in 400% in the last 5 breeding seasons. There are two main areas used by penguins to breed, molt or rest, one near the Marazzi River and the other one near the marine coast. The breeders always used the same area while non breeders can use both areas depending on weather conditions. Five molting periods were observed for breeders and non-breeders during the year. Complete breeding failure was observed for this colony until 2014-2015 season, where the first chick survived throughout the year. Most chicks died when they were 4 months of age. Cause of chick death was determined performing necropsies or by macroscopic findings: 60% of them showed lesions caused by infectious agents and others very likely died from starvation. The main predator registered in the past was the introduced american mink (Neovison vison), but predator control actions reduced this mortality. The grey fox (Leucolopis griseus) was observed predating on eggs and scavenging dead chicks, but we didn?t observed them attacking penguins. Monitoring of this new colony is helping to disentangle the main challenges King Penguins face to establish new colonies and recolonize breeding grounds.