Skip Navigation



Behavioral Ecology Advance Access published online on September 6, 2006
Behavioral Ecology, doi:10.1093/beheco/arl043
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow Lay Summary
Right arrow All Versions of this Article:
17/6/1041    most recent
arl043v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Pomeroy, A. C.
Right arrow Articles by Ydenberg, R. C.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Pomeroy, A. C.
Right arrow Articles by Ydenberg, R. C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2006. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org
Received January 17, 2006
Revised May 16, 2006
Accepted August 5, 2006

Article

Experimental evidence that migrants adjust usage at a stopover site to trade off food and danger

Andrea C. Pomeroy 1 *, Robert W. Butler 2, and Ronald C. Ydenberg 1

1 Centre for Wildlife Ecology and Behavioural Ecology Research Group, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
2 Centre for Wildlife Ecology and Behavioural Ecology Research Group, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada; Pacific Wildlife Research Centre, Canadian Wildlife Service, 5421 Robertson Road, Delta, British Columbia V4K 3N2, Canada

* To whom correspondence should be addressed.
Andrea C. Pomeroy, E-mail: apomeroy{at}sfu.ca


  Abstract

Rich habitats, intensive feeding, and large fuel deposits are assumed to improve the capability for long-distance migration by birds but may also heighten their vulnerability or exposure to predators. Studies of habitat use by migrants have emphasized the importance of feeding, and relatively few studies have considered how migrants manage the dangers inherent in acquiring and storing fuel. Migrant western sandpipers (Calidris mauri) stop over on coastal mudflats characterized by a strong feeding-danger gradient, with both food and danger decreasing with distance from the shoreline. We experimentally manipulated danger by adding obstructive cover and measured sandpiper usage along this gradient. We compared sandpiper usage along a transect extending 100 m on either side of the obstruction with that on matched control transects without obstructions. The dropping density accumulated during a low-tide period provided a sensitive measure of sandpiper usage. Mean usage on control transects was 2.3 droppings/m2 and was lower by 1.5 droppings/m2 (65%) on treatment transects. Usage did not differ between control and treatment transects at the furthest distances from the obstruction, the difference increased with proximity to the obstruction, and was greater by on average 0.9 droppings/m2 on the oceanward side (low food abundance) than on the shoreward side (high food abundance). All these findings were predicted by danger management theory. Our study provides experimental evidence that migrant birds are sensitive to danger on stopover and has implications for understanding migration strategies.

Keywords: food abundance; migration; predation danger; stopover site usage; trade-off hypothesis; western sandpiper.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.