Matthew Evans
mrevans@sfu.ca Ph.D. student Title of thesis: Nesting
and Brood-rearing Habitat Requirements of Cavity Nesting Waterfowl: Barrow's
Goldeneye and Bufflehead. Supervisors: Fred Cooke,
David Lank, Sean Boyd (CWS) Short biography: Summary of current research: Both Barrow's Goldeneye (Bucephala
islandica) and Bufflehead (B. albeole) are secondary cavity
nesters and rely heavily on nest sites created by primary cavity nesters
such as Pileated Woodpeckers (Dryocopus pileatus) and Northern Flickers
(Colaptes auratus), respectively. However, studies of natural cavity
selection and success by these birds are lacking. Prior studies have predominantly
made use of artificial nest boxes. This study examines the biophysical
characteristics of cavity nest sites (tree species, decay class, dbh, distance
from water, and distance from forest edge) and compares reproductive parameters
between birds nesting in cavities to those in nest boxes. Sources of nest
failure and patterns of nest site philopatry for both cavities and nest
boxes are also being examined. Obtaining a suitable nest site
is generally of paramount importance to breeding success in secondary cavity
nesting birds. Barrow's Goldeneye is a cavity nesting duck that defends
exclusive brood rearing areas on ponds, and this defense has been interpreted
as defense of food, suggesting that variation in pond quality is also quite
important. Furthermore, reproduction in birds is timed so that the breeding
cycle coincides with maximum availability of food for nesting adults or developing young. Recruitment among waterfowl
may be particularly sensitive to the quantity and quality of food resources
available, both in terms of the energy and nutritional requirements of
egg-laying females as well as the growth and developmental requirements
of ducklings. Protein acquisition via invertebrate consumption potentially
limits clutch size in waterfowl, hence availability of invertebrates
may be a cue affecting wetland use and ultimately recruitment. Therefore,
habitat quality significantly effects reproductive parameters such as 1)
timing of reproduction; 2) propensity to breed; 3) clutch size; 4) egg
mass and composition; 5) offspring growth and survival; and 6) overall
reproductive success. We are currently examining these and other aspects
of Goldeneye and Bufflehead breeding ecology. The period of growth and
development is one of the most important, yet, least studied, periods in the life cycle
of waterfowl. Nutrition during the growth period is likely to influence
duckling survival and future reproduction by its effect on size and nutrient
reserves. Growth characteristics of interest to us are: 1) asymptotic size
approached by a sigmoidal growth process; 2) growth rate: a measure of
the total amount of time required to reach the asymptotic limit, expressed
as the rate of amount of body mass gained per unit time; and 3) the path
or trajectory taken by the growth process to approach the asymptote (see
Brisbin et al. 1986). Funding Agencies: NSERC, Science Horizons, Forest Renewal British Columbia,
Environment Canada, Canadian Wildlife Service, West Fraser Mills Ltd., Riverside Forest Products Ltd., and Simon Fraser University. Recent Publications: Manuscripts: M. Evans, D. Lank, F. Cooke, and
W.S. Boyd. The Breeding Ecology of Barrow's Goldeneye and Bufflehead in
Natural Cavities and Nest Boxes. Submitted to The Auk, September, 2000. Technical Reports: M. Evans. Sea Duck Joint
Venture Species Account For Barrows Goldeneye Populations Across North
America. North American Sea Duck Joint Venture (2000). M. Evans. Sea Duck Joint
Venture Species Account For Bufflehead Populations Across North America.
North American Sea Duck Joint Venture (2000). Oral Presentations given at Scientific Meetings: M.
Evans, D. Lank, F. Cooke, and W.S. Boyd. The Breeding Ecology of Barrow's
Goldeneye and Bufflehead in Natural Cavities and Nest Boxes. Joint Ornithological
Meeting between The Society of Canadian Ornithologists, The American Ornithological
Union, and The British Ornithological Union. St. John's, Newfoundland (2000). M. Evans, D. Lank, F. Cooke, and
W.S. Boyd. Brood Rearing Habitat Selection by Barrow's Goldeneye and Its
Effect On Duckling Growth, Survival, and Return Rates. North American Duck
Symposium, Saskatoon, Saskatchewan. (2000). Poster
Presentations Given at Scientific Meetings (1999-2000): M. Evans, D. Lank, F. Cooke, and
W.S. Boyd. Natural Cavity Selection by Barrows Goldeneye and Bufflehead,
and a Comparison to Nest Box Usage. North American Duck Symposium, Saskatoon,
Saskatchewan. (2000). M. Evans, D. Lank, F. Cooke, and
W.S. Boyd. Brood Rearing Habitat Selection by Barrow's Goldeneye and Its
Effect On Duckling Growth, Survival, and Return Rates. Joint Ornithological
Meeting between The Society of Canadian Ornithologists, The American Ornithological
Union, and The British Ornithological Union. St. John's, Newfoundland (2000). M. Evans, D. Lank, F. Cooke, and
W.S. Boyd. Natural Cavity Selection by Barrows Goldeneye and Bufflehead.
Cooper's Ornithological Meetings, Riverside, California. (2000). M. Evans and A. Breault.
Identification of Bufflehead Moulting Sites in Interior British Columbia.
Cooper's Ornithological Meetings, Riverside, California. (2000). Presentations made by co-authors
at Scientific Meetings (1999-2000): W.S.
Boyd and M. Evans. Juvenile Survival in Barrows Goldeneye. North
American Duck Symposium, Saskatoon, Saskatchewan. (2000). B. Smith,
W.S. Boyd, and M. Evans. Modeling Predation Events and Juvenile Survival
in Barrows Goldeneye. North American Duck Symposium, Saskatoon, Saskatchewan.
(2000). A. Breault
and M. Evans. Identification of Seaduck and Waterbird Moulting Areas
in the B.C. Interior. Pacific Flyway Symposium, Newport, Oregon. (2000). A. Breault
and M. Evans. Waterfowl Moulting Sites in Interior British Columbia.
North American Duck Symposium, Saskatoon, Saskatchewan. (2000). |
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