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 Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Parental care influences the feeding behaviour of female eiders Somateria mollissima

Markus Öst and Mikael Kilpi
Annales Zoologici Fennici
Vol. 36, No. 4 (1999), pp. 195-204
Stable URL: http://www.jstor.org/stable/23735727
Page Count: 10
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Parental care influences the feeding behaviour of female eiders Somateria mollissima
Preview not available

Abstract

We compared the feeding behaviour of lone tenders, multi-female tenders and post-breeding, non-tending eider females Somateria mollissima in the northern Baltic. Few prey species are available for eiders in the Baltic; in the non-breeding season adults prefer blue mussels Mytilus edulis, whereas small ducklings feed primarily on gammarids Gammarus spp. Infections by the acanthocephalan parasite Polymorphus minutus occur when eiders feed on gammarids and this infection may be fatal if the host's resistance is low. The mussel beds and areas with gammarids are close together but do not overlap. Assuming that females always should prefer blue mussels to gammarids we tested the following predictions: (i) non-tending females should exclusively feed on mussels, (ii) lone tenders may be forced to feed like their young, and (iii) multi-female tenders may occasionally utilise mussels, thereby mitigating constraints associated with consumption of unprofitable gammarid prey. Tending females foraged like their young, whereas non-tending females fed on mussels throughout the brood-rearing season. Individually marked females fed on mussels immediately after losing their brood, suggesting that a conflict between female and duckling feeding needs exists during early brood-rearing. However, later in the season all females and young fed on mussels. Multi-female tenders achieved no obvious foraging benefits compared to lone tenders, indicating that crèching in eiders may have primarily evolved for other reasons.

Page Thumbnails

  • Thumbnail: Page 
[195]
    [195]
  • Thumbnail: Page 
196
    196
  • Thumbnail: Page 
197
    197
  • Thumbnail: Page 
198
    198
  • Thumbnail: Page 
199
    199
  • Thumbnail: Page 
200
    200
  • Thumbnail: Page 
201
    201
  • Thumbnail: Page 
202
    202
  • Thumbnail: Page 
203
    203
  • Thumbnail: Page 
204
    204