Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

Aggregation Patterns of Pelagic Predators and their Principal Prey, Antarctic Krill, near South Georgia

Richard R. Veit, Emily D. Silverman and Inigo Everson
Journal of Animal Ecology
Vol. 62, No. 3 (Jul., 1993), pp. 551-564
DOI: 10.2307/5204
Stable URL: http://www.jstor.org/stable/5204
Page Count: 14
  • Get Access
  • Read Online (Free)
  • Download ($18.00)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
Aggregation Patterns of Pelagic Predators and their Principal Prey, Antarctic Krill, near South Georgia
Preview not available

Abstract

1. We examined the spatial distributions of pelagic seabirds and fur seals near South Georgia, and asked to what extent the distributions of these predators were influenced by the spatial distribution of their principal prey, Antarctic krill Euphausia superba Dana. One novel aspect of our analysis is an explicit consideration of the separation in space between swarms of krill and aggregations of predators that feed upon krill. 2. Our data were collected in February 1986, during a systematic shipboard survey of the waters surrounding Bird Island, South Georgia. Predator abundance was estimated visually using strip transects, and krill abundance was simultaneously estimated using a hull-mounted echosounder. 3. We approached the difficult analytical problems associated with spatial distributions of organisms by using spatial autocorrelation and cross-correlation analysis, regression models with spatial terms, and randomization tests. The randomization tests involved repeated simulations of predator distributions, and subsequent estimation of spatial association between predators and prey. 4. Pelagic birds and seals were distributed in a strikingly non-random fashion at sea near South Georgia; their distributional patterns were strongly influenced by the distribution of krill swarms. 5. Differences between predators in their spatial distribution and in their response to krill swarms suggest interspecific differences in foraging strategies.

Page Thumbnails

  • Thumbnail: Page 
551
    551
  • Thumbnail: Page 
552
    552
  • Thumbnail: Page 
553
    553
  • Thumbnail: Page 
554
    554
  • Thumbnail: Page 
555
    555
  • Thumbnail: Page 
556
    556
  • Thumbnail: Page 
557
    557
  • Thumbnail: Page 
558
    558
  • Thumbnail: Page 
559
    559
  • Thumbnail: Page 
560
    560
  • Thumbnail: Page 
561
    561
  • Thumbnail: Page 
562
    562
  • Thumbnail: Page 
563
    563
  • Thumbnail: Page 
564
    564