Foraging under contrasting oceanographic conditions: the gentoo penguin at Kerguelen Archipelago

Abstract

Coastal seabirds are bound to be dependent on local marine resources. We hypothesize that the localization of the breeding colony will influence the foraging patterns of such predators. The foraging behavior of gentoo penguins Pygoscelis papua was investigated in contrasting marine environments at Kerguelen Archipelago over the 2002-03 and 2003-04 breeding seasons. Using timedepth recorders (TDRs) and satellite transmitters, we describe the at-sea distribution and diving behavior of gentoo penguins breeding in 2 colonies facing the open sea (Open Sea 1 and Open Sea 2) and 1 colony protected in a closed bay (Closed Sea). The foraging behavior varies extensively across the Kerguelen Archipelago, almost as much as it does over the entire range of the species. Different foraging strategies emerge, depending on the local conditions: large foraging ranges, long trips, long benthic dives on demersal fish at Open Sea colonies versus small foraging ranges, short trips, short pelagic dives on swarming crustaceans at Closed Sea, for a same foraging effort. The diving behavior of the gentoo penguin therefore varies as a function of the locality and the site, closely related to prey availability. This study demonstrates the importance of foraging plasticity as a fundamental aspect of life history in coastal marine predators.

Foraging distance affects reproductive success in Magellanic penguins

“…Differences in foraging-trip distance or duration within species among years are common in multi-year studies and likely reflect changes in prey availability (e.g. Kitaysky et al 2000, Ballard et al 2001, Boersma et al 2002, Lescroël & Bost 2005. Variability among individuals from the same colony is probably common as well (Ballard et al 2001), reflecting factors such as age, experience, body condition, and number and size of chicks.…”

“…Trip distance often varies across the breeding season, reflecting different constraints (Weimerskirch et al 1993, Guinet et al 1997, Beauplet et al 2004, Lescroël & Bost 2005, Phalan et al 2007). Older chicks have greater food needs and greater storage capacity than younger chicks (Walker & Boersma 2003) which may both require and allow adults to go farther to forage when chicks are older.…”

Plasticity in foraging strategies of inshore birds: how Little Penguins maintain body reserves while feeding offspring

“…Inshore seabirds do not rely on distant food resources and usually perform short foraging trips to coastal areas close to their breeding sites, as, for instance, in Black-browed and Shy Albatrosses, or Ade´lie Penguins (Weimerskirch et al 1986, Hedd 1998, Ballard et al 2010. Some inshore species also exhibit a dual pattern of short and long trips either in duration or distance (see murres in Benvenuti et al 1998 and Gentoo Penguins in Lescroe¨l and Bost 2005). However, this dual pattern resulted from a mutually exclusive behavior, i.e., some birds conducted short trips, while others conducted long ones (depending on sex, breeding site location, and so on).…”

Variability in foraging behaviour of chick-rearing macaroni penguins Eudyptes chrysolophus and its relation to diet

“…In several studies on penguins, changes in foraging behaviour parameters of the populations do correlate with changes in diet (Green et al 1998, Moore et al 1999, Lescroël & Bost 2005. However, relatively few studies combine behavioural and diet data from the same individual animals to test this linkage.…”

“…Studies on penguins have documented substantial changes in foraging behaviour within species from different locations (e.g. Tremblay & Cherel 2003, Lescroël & Bost 2005 and during different phases of the annual cycle (e.g. Charrassin et al 2002, Green et al 2005, Clarke et al 2006.…”