R.
Will Stein
Department
of Biological Sciences
Simon Fraser University
8888 University Drive
Burnaby, B.C. V5A 1S6
Canada
Phone:(778)
782-5422
Fax:(778)
782-3496
Supervisor: I completed my M. Sc. degree with Dr. Tony Williams.
My project focused on physiological determinants of migratory performance in the Western Sandpiper (Calidris mauri).I did this work as part of the Centre for Wildlife Ecology at Simon Fraser University. One of the directives of the CWE is to examine how migratory birds respond to changing landscapes.The
Western
Sandpiper
migrates through the Pacific Flyway, and it is one of the focal species of the CWE.
Biography
I completed my B.Sc. at the University of California, Davis. One course in particular had a formative impact on my developing perspectives towards ecology; that course was patterns in avian biology. It turns out that this was actually a course in physiological ecology of birds, and, as I found out, research in this field both addresses and explores physiological adaptation in response to selection pressures exerted by dynamic and challenging environments. This combination of physiological and evolutionary approaches to ecology offers a complementary addition to the modeling approaches of behavioural ecology.
After I completed my B. Sc. I spent a couple of years working at the University of California, Davis, on large-scale projects in ecotoxicology. After I left Davis I worked on a variety of field studies. I spent two seasons studying the energetics of Spring migrating Pectoral Sandpipers (Calidris melanotos) in northwest Missouri, and, just a week later, studying shorebird reproductive biology on the North Slope of Alaska. This was an exceptional opportunity to observe a number of species in migration and, immediately thereafter, on the breeding grounds. My interest in migration physiology developed during this time, as did my appreciation for the magnitude of selection exerted on the physiological capacities of long distance migrants.
Current
Research
Photo: G. Fernandez Aceves
Busting
a gut: Age-related differences in digestive tract structure and function
during migration in Western Sandpipers.
The absorptive components of the digestive tract, i.e. small intestine, large intestine, and ceca, are disproportionately large (wet mass) in juvenile Western Sandpipers during the first southward migration. In fact, the small intestine is at its highest mass of the entire life cycle during the first migration. This situation is in striking contrast to the finding that other long distance shorebird migrants downsize their gut prior to migratory departure (Piersma, T. and R. E. Gill, jr., 1998).Due to the importance of juvenile recruitment to population stability, I am examining the functional importance of this structural difference to the survival strategy of migrating juveniles. The small intestine is responsive to changes in energy demands in a predictable manner and is used here as a model system to assess performance in meeting energy demands during migration. The question central to this study is what are the costs and benefits of maintaining and carrying a large gut during migration for juveniles. It is likely that there are flight costs associated with carrying a large gut, both in terms of flight range and take off speed. However, if a larger gut increases nutrient assimilation rates this could be strategically important for juveniles.
I have a long-standing interest in female parental investment strategies within the lineage of birds with precocial young. It is unusual for adults to provision precocial young after hatch, though it does occasionally occur. However, in most instances the female's investment in the clutch can be considered as a measure of the female's annual parental investment. Measures of female parental investment are easily obtained from previously published data on female mass, egg mass, and clutch size. I have pursued these interests with literature based studies, and use the new comparative methods to take phylogenetic history into account in these interspecific comparative analyses.
Acknowledgements
Primarily, I want to acknowledge my supervisor, Tony Williams, for excellent supervision, help in the field and in the lab, a good sense of humour, good taste in scotch, and an ability to emphasize the positive. I
have had so much help in the field and in the lab, but in particular, Peggy
Yen, Rahul Ray, Darren Lissimore, Suchita Nath, and Wendell Challenger
were essential components of this project. Funding
from Northern Scientific Training Program allowed me to send Rahul to Nome,
Alaska, for fieldwork. Research funding through the CWE allowed me to undertake this research project.
I
also want to acknowledge those I have collaborated with. In
addition to my supervisor, at SFU Dr. Christopher G. Guglielmo was instrumental
with great ideas and guidance. I learned the ëverted sleeve technique under the supervision of Bruce Darken at Dr. William H. Karasov's lab, which is located at the University of Wisconsin at Madison. I assayed pancreatic lipase at Dr. Allen R. Place's lab at the University of Maryland's Center of Marine Biotechnology in Baltimore. I assayed aminopeptidase-N at Dr. Carlos Martinez del Rio's lab at the University of Wyoming at Laramie. All
of these people were helpful and accommodating in allowing me to visit
and learn these techniques.
Recent Publications and Conference Presentations
Stein,
R.W., J.T. Yamamoto,
D.M. Fry, and B.W. Wilson. 1998. Comparative hematology and plasma biochemistry
of red-tailed hawks and American kestrels wintering in California.Journal
of Raptor Research32(2): 163-169.
Fry, D.M., B.W. Wilson, N.D. Ottum, J.T. Yamamoto, R. W. Stein, J.N. Seiber, M.M. McChesney, and E. Richardson. 1998. Radiotelemetry and GIS computer modeling as tools for analysis of exposure to organophosphate pesticides in red-tailed hawks.In: Radiotelemetry applications for wildlife toxicology field studies, L. Brewer and K. Fagerstone, eds. SETAC Press, Pensacola FL. Pgs. 67-84.