Western Sandpiper (Calidris mauri

Western Sandpiper in breeding plumage.  Photo: Pavel Tomkovitch 

The Western Sandpiper, Calidris mauri, is the most abundant shorebird in Western North America, numbering from 2-4 million individuals.  Up to half a million Western Sandpipers pass through the Fraser River Delta on their northward migration each spring, making it a species of local interest and importance.

Members of the Wildlife Ecology Chair at Simon Fraser University, located near Vancouver, British Columbia, are engaged in research on this species throughout its annual range, from Alaska to Ecuador.   We also foster a cooperative network to examine the year-round activities of highly migratory shorebirds, emphasizing the Western Sandpiper, the Western Sandpiper Research Network.  

Major aspects of work, and participants, include:

feeding-predation danger tradeoffs, particularly at migratory stopover sites (Ron Ydenberg and David Lank at SFU, Rob Butler (Canadian Wildlife Service), plus graduated PhD student Andrea Pomeroy, and MSc students Nick Wolfe and James Burns; currently: MSc student David Hope). To view a video of over ocean flocking by dunlin, click here.

breeding biology in Alaska (graduated PhD students Brett Sandercock and Doug Schamel; MSc student Amanda Neihaus currently: Sarah Jameison, focusing on dunlin)

field studies of overwintering birds at a northerly site (Dunlin: graduated Ph.D. students Pippa Shepherd and Lesely Evans Ogden, postdoctoral fellow Yuri Zharikov)

field studies on the wintering grounds in NW Mexico (graduated PhD student Guillermo Fernandez,in collaboration with Horacio del la Cueva, from CICESE near Ensenada, Baha California);

field studies on the wintering grounds in Panama (graduated PhD student Patrick O'Hara,in collaboration with F. Delgado, Univ. de Panama)

diet, particularly adaptations to feeding on biofilm (Bob Elner, CWS, and collaborator Tomahiro Kuwae)

physiological studies of relative organ size, fat levels, and protien utilization throughout the annual cycle by Tony Williams (SFU) and his graduated students Chris Guglielmo, Oliver Egler, Will Stein, and Dana Seaman;

radiotracking individuals during spring migration (Nils Warnock and Mary-Anne Bishop, and Pat Baird)

modeling migration strategies (Colin Clark, UBC, currently postdoctoral fellow Caz Taylor)

documenting and explaining differential migration distribution of age and sex classes during the non-breeding season (Ron Ydenberg, David Lank; graduated PhD students Silke Nebel and Patrick O'Hara, and MSc student Kim Mathot; Bob Elner at CWS)

migratory connectivity using stable isotopes, trace elements, and genetics and morphology (David Lank, D Ryan Norris, Kurt Kyser (Queen's Univ), MSc student Samantha Franks)

life history and demographic modeling of sandpiper populations (Brett Sandercock, Caz Taylor and David Lank)

conservation biology (graduated PhD student Guillermo Fernandez, David Lank, Rob Butler (CWS), others)

We have additional contacts and relationships with shorebird students in Ecuador, Columbia, Mexico, California, Oregon, Washington, and elsewhere.

One emerging general theme in this research is how birds balance the tradeoff between foraging effort and the risk of predation, particularly by migratory falcons. The return of falcons to the landscapes of both the Americas and Europe over the past 20 years have substantial implications for their prey. We have evidence of changes in habitat utilization during migration, with decreased usage of riskier stopover sites in favor of larger more open sites, despite apparently poorer feeding at the larger sites. Such habitat shifts, if general have substantial implications for the shorebird population monitoring schemes and the detection of long-term population trends. Another change is the dramatic increase in over-ocean flocking by wintering dunlin as an anti-predation strategy during high tides. To view a video of over ocean flocking by dunlin, click here.

We have organized 10 somewhat annual "Western Sandpiper Workshops" over the past 14 years to foster collaboration and communication among research network participants and other interested persons.

Abstracts from two workshops are linked below:

Abstracts from 7th Western Sandpiper Workshop, Jan 2003
Abstracts from 6th Western Sandpiper Workshop, Oct 2000

Major activities of our research group and network were summarized in a set of forward-looking essays published in the Wader Study Group Bulletin's #100 issue.  PDF files of these reviews are linked below:

"Cross-seasonal and cross-disciplinary interactions: synergy from studying the year-round physiology, behaviour, and population biology of migratory shorebirds." Silke Nebel and David B. Lank. 2003. Wader Study Group Bull. 100:118-121.

"Wader migration on the changing predator landscape."  Robert W. Butler, Ron C. Ydenberg, R.C. and David B. Lank. 2003. Wader Study Group Bull. 100:130-133.

"Calidrid conservation: unrequired needs."  Robert W. Elner and Dana Seaman. 2003. Wader Study Group Bull. 100:30-34.

"Integrating marine and terrestrial habitats in shorebird conservation planning."  Philippa C.F. Shepherd, Lesley J. Evans Ogden and David B. Lank. 2003. Wader Study Group Bull. 100:40-42.

Click for a list of Shorebird publications by CWE researchers.  PDF files of selected additional papers are linked below:

"Nebel, S., D.B. Lank, P.D. O'Hara, G. Fernández, B. Haase, F. Delgado, F.A. Estela, L.J. Evans Ogden, B. Harrington, B.E. Kus, J.E. Lyons, F. Mercier, B. Ortego, J.Y. Takekawa, N. Warnock and S.E. Warnock. 2002. Western Sandpipers (Calidris mauri) during the non-breeding season: spatial segregation on a hemispheric scale. "   Auk 119: 922-928.

"Sandercock, B.K., D.B. Lank and F. Cooke. 1999. Seasonal declines in the fecundity of arctic-breeding sandpipers: different tactics in two species with an invariant clutch size. "   J. Avian Biol. 30: 460-468.

"Hitchcock, C., Gratto-Trevor, C. 1995. Diagnosing a shorebird local population decline with a stage-structured population model. "   Ecology 78: 522-534.

"Fernández, G., H. de la Cueva, N. Warnock, and D. B. Lank. 2003. Apparent survival rates of Western Sandpiper (Calidris mauri) wintering in northwest Baja California, Mexico. "   Auk 120: 55-61

"Lank, D.B., R.W. Butler, J. Ireland and R.C. Ydenberg. 2003. Effects of predation danger on migratory strategies of sandpipers. "   Oikos 103:303-319.

"Ydenberg, R.C., R.W. Butler, D.B. Lank, C.G. Guglielmo and M. Lemon. 2002. Trade-offs, condition dependence, and stopover site selection by migrating sandpipers. "   J. Avian Biol. 33:47-55.

Updated 2007-09-05