The Barrows Goldeneye, A
vulnerable bird
http://www.qc.ec.gc.ca/faune/sauvagine/html/information_bg.html
The Breeding of Barrows Goldeneye Finally Documented
http://www.qc.ec.gc.ca/faune/sauvagine/html/nesting_bg.html
Barrows Goldeneye Satellite Tracking Spring 1999
http://www.qc.ec.gc.ca/faune/sauvagine/html/satellite_bg.html
Egg laying intervals and nutrient reserve use of breeding
female buffleheads and Barrow's goldeneyes.
Jonathan E. Thompson & C. Davison Ankney.
http://www.tpwd.state.tx.us/nature/wild/birds/buffhead.htm
Parasitism, Population Dynamics And Hybridization In
Cavity- Nesting Seaducks
EADIE, JOHN McA. Department of Wildlife, Fish and Conservation Biology,
University of California, Davis, CA 95616,
ANSTEY, DAVID A. Division of Sciences, University of Toronto, Scarborough,
ON M1C 1A4 Intraspecific and interspecific brood parasitism occur
frequently in waterfowl. We examine the consequences of these behaviors to
the population dynamics of Barrow's and Common Goldeneyes during a 10 year
study period in central British Columbia. The frequency of parasitism was
significantly related to population density and to the availability of
nest sites. High levels of parasitism, in turn, resulted in reduced
reproductive success of females. Using a simulation model based on field
data, we demonstrate that high frequencies of intraspecific parasitism can
lead to the extirpation of local populations. Brood parasitism between
species leads to the additional complication that parasite offspring may
become sexually imprinted on the host species, thereby facilitating
cross-mating and interspecific hybridization. We test this hypothesis
using (1) a comparative analysis of the Anseriformes and (2) field studies
and molecular genetic analyses of interspecific hybridization in
goldeneyes. Our results demonstrate that social interactions such as brood
parasitism may play an important role in determining the long-term
viability of local populations.
Anderson, M.G., R.D. Sayler and A.D. Afton. 1980. A decoy
trap for diving ducks. J. Wildl. Manage. 44:217-219
Andrew D.G. 1960 Aggressive Behaviour of Barrows Goldeneye with Young
British Birds 53: 572-573
Beil, C.E. 1974. Forest associations of the southern
Cariboo Zone. British Columbia. Syesis 7:201-233.
Bengtson, S.A. 1970 Location of nest-sites of Ducks in
Lake Myvatn area, north- east Iceland. Oikos 21:218-229
Bengtson, S.A. 1971 Habitat selection of ducks broods in
Lake Myvatn area, north- east Iceland.
Ornis Scand. 2:17-26. 21:218-229 Brooks, A. 1903. Notes on the birds of
the Cariboo district, B.C. Auk 20:277-284.
Egg Laying Intervals And Nutrient Reserve Use Of Breeding
Female Buffleheads And Barrow's Goldeneyes
THOMPSON, JONATHAN E. Department of Zoology, Ecology and Evolution Group,
University of Western Ontario, London, Ontario, Canada N6A 5B7 and Caesar
Kleberg Wildlife Research Institute, Texas A&M University -
Kingsville, Campus Box 218, Kingsville, Texas 78363 ANKNEY, C. DAVISON.
Department of Zoology, Ecology and Evolution Group, University of Western
Ontario, London, Ontario, Canada N6A 5B7
This study was conducted to investigate nutritional aspects of
reproduction in female Buffleheads (Bucephala albeola) and Barrow's
Goldeneyes (Bucephala islandica) breeding in central British Columbia in
1993 - 95. Mean egg laying interval (Ò SE) for Buffleheads was 48.36 Ò
2.35 hr, which was similar to that of Barrow's Goldeneyes that laid, on
average, every 45.32 Ò 1.40 hr. As a consequence of slower rates of egg
production, daily energetic costs of reproduction in female Buffleheads
and Barrow's Goldeneyes, evaluated relative to their basal metabolic
requirements, are among the lowest documented for ducks. Patterns of
lipogenesis differed between female Buffleheads and Barrow's Goldeneyes,
but both species catabolized somatic fat during egg production.
Buffleheads maintained stable body protein during reproduction, and thus
relied exclusively on dietary protein for clutch formation, whereas
Goldeneyes catabolized small amounts of somatic protein to produce egg
protein during the 1993 breeding season. Use of body protein by a
primarily carnivorous duck suggests that protein availability, i.e.,
invertebrate abundance, in breeding habitats used by Goldeneyes was
periodically deficient. Somatic mineral supplied approximately 8% of
clutch minerals in Buffleheads and 3% of clutch minerals in Goldeneyes
during the 1993 breeding season, but neither species used endogenous
minerals for eggshell production in 1994. Size of somatic lipid and
protein reserves apparently did not limit clutch size in either
Buffleheads or Barrow's Goldeneyes. Furthermore, clutch size was
apparently not constrained by size of somatic mineral reserves in
Buffleheads. However, body mineral mass was positively related to clutch
size in Barrow's Goldeneyes. Thus, from a nutritional perspective, our
data suggest that size of mineral reserves may limit clutch size in
Barrow' Goldeneyes, whereas relatively low rates of nutrient reserve use
indicate that clutch size in Buffleheads may not be constained by size of
these reserves. |