nerc.ac.uk

Diet and reproductive success of Adélie and chinstrap penguins: linking response of predators to prey population dynamics

Lynnes, A.S.; Reid, K.; Croxall, J.P.. 2004 Diet and reproductive success of Adélie and chinstrap penguins: linking response of predators to prey population dynamics. Polar Biology, 27 (9). 544-554. 10.1007/s00300-004-0617-1

Full text not available from this repository.

Abstract/Summary

The diet and reproductive performance of two sympatric penguin species were studied at Signy Island, South Orkney Islands between 1997 and 2001. Each year, Adelie (Pygoscelis adeliae) and chinstrap (P. antarctica) penguins fed almost exclusively (>99% by mass) on Antarctic krill; however, there was considerable inter-annual variation in reproductive output. In 1998, chinstrap penguins were adversely affected by extensive sea-ice in the vicinity of the colony, whereas Adelie penguins were unaffected by this. However, in 2000, both species suffered reduced reproductive output. Detailed analysis of the population-size structure of krill in the diet indicated a lack of recruitment of small krill into the population since 1996. A simple model of krill growth and mortality indicated that the biomass represented by the last recruiting cohort would decline dramatically between 1999 and 2000. Thus, despite the lack of a change in the proportion of krill in the diet, the population demographics of the krill population suggested that the abundance of krill may have fallen below the level required to support normal breeding success of penguins sometime before or during the 2000 breeding season. The role of marine predators as indicator species is greatly enhanced when studies provide data reflecting not only the consequences of changes in the ecosystem but also those data that elucidate the causes of such changes.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1007/s00300-004-0617-1
Programmes: BAS Programmes > Antarctic Science in the Global Context (2000-2005) > Dynamics and Management of Ocean Ecosystems
ISSN: 0722-4060
NORA Subject Terms: Marine Sciences
Zoology
Ecology and Environment
Date made live: 20 Jan 2012 11:55
URI: http://nora.nerc.ac.uk/id/eprint/12255

Actions (login required)

View Item View Item