Breeding Ecology Of The Goldeneye (Bucephala clangula) in artificial nests
Ornithologica 16:22-32 (In Russia)
Ornithologica 16:22-32 (In Russia)
Can. Field-Nat. 96:295- 300.
Ornithol. Monogr. No. 18
Because of their relative unimportance to recreational hunters, almost nothing is known about the population dynamics of waterfowl in the tribe Mergini in North America. Species-specific annual survival estimates are important to ecologists and managers both for understanding the evolution of life histories and for implementation of management plans. Using capture-recapture methodology, we estimated annual survival of female Hooded Mergansers breeding in man-made nest boxes in southeast Missouri from 1987 - 1995.
In 1993-1996, we studied the breeding ecology of a small concentrated population of Surf Scoters Melanitta perspicillata on the southern edge of the breeding range in Quebec. We documented, for the first time, laying dates, clutch sizes, nest-site characteristics, nesting success, brood home ranges, duckling survival, and growth rates. A summary of our results is presented and comparisons made with with other recent, but less detailed information obtained further north in the heartland of the breeding range.
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.
In response to the dramatic decline of the species (early 1970's to 1990's) on the Yukon-Kuskokwim Delta, I conducted a nesting ecology study on spectacled eiders (Somateria fischeri) at Kigigak Island from 1992-1996. The Kigigak Island population has had relatively high nest success between 1992-1996 (92%, 63%, 70%, 64%, and 82%, respectively). More than 50% of the nesting females have been marked (n=161). Preliminary results show that 70% of the marked females have returned to nest at least once following their banding year and that 52% returned at least two consecutive years.
Spectacled Eider (Somateria fischeri) populations in western Alaska have declined precipitously since the late 1970's. Subsequently, the species was listed as threatened in 1993. To investigate the potential causes of the decline, we developed a deterministic model of Spectacled Eider population dynamics based on demographic data we collected on the Yukon-Kuskokwim Delta, Alaska, from 1991-1996. The model incorporated estimates of nest success, clutch size at hatch, duckling survival, age of first reproduction, and adult female survival collected at a two locations.
We sequenced a hypervariable 319 bp portion of the control region of mitochondrial DNA in five subspecies of Common Eiders (Somateria mollissima) and an outgroup sample of King Eiders (S. spectabilis). Variation was found at 71 sites (22%), which defined 56 haplotypes in the total sample. A genealogical tree relating the haplotypes revealed three major clades, but with the exception of Common Eiders (S. v-nigra) from Alaska, they did not correspond with putative subspecies identities.