Resources related to Reproduction

Annual Survival Of Southern Breeding Female Hooded Mergansers

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.

Breeding Ecology Of The Surf Scoter: Gathering Basic Data On The Last Of The Undocumented Species

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.

Philopatry In Nesting Adult Female Spectacled Eiders At Kigigak Island, Yukon Delta National Wildlife Refuge, Alaska

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.

Mitochondrial DNA control region sequence variation in Common Eiders reveals extensive mixing of subspecies

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.

Pre-hatch brood amalgamation in common eiders: why do eiders adopt eggs?

Pre-hatch brood amalgamation(intraspecific nest parasitism) was studied for three years (1991-1993) in a colony of common eiders (Somateria mollissima) breeding near Churchill, Manitoba. The amalgamation rate was highest (42.4% of nests) during the year with the highest nest density and good environmental conditions, and was lowest in the year with low nest density and poor conditions (20.2% of nests). Over the nesting season, foreign eggs were laid at the same time as normally laid eggs. Most foreign eggs were laid while the attendant female was laying her first and second eggs.

The effect of body condition on subsequent creche attendance in Common Eiders (Somateria mollissima)

Creches are groups containing any number of adult female(s) and duckling(s), two or more of which are parentally unrelated. Several authors have suggested that the body condition of ducks is a determining factor in parental care and that females in poor condition more readily abandon their young. In 1997 and 1998, 285 adult female Common Eiders breeding on Green Island were captured and nasal tagged. Our objective was to examine the relationship between adult female condition, using multiple measures of body size, and subsequent membership in creche.

Breeding Biology Of King Eiders Nesting On Karrak Lake, N.W.T.

Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada S7N 5E2 ALISAUSKAS, RAY T. Prairie and Northern Wildlife Research Centre, Canadian Wildlife Service, 115 Perimeter Road, Saskatoon, Saskatchewan, Canada S7N 0X4 We studied various aspects of the breeding biology of king eiders (Somateria spectabilis) nesting at Karrak Lake, south of Queen Maud Gulf in the central Canadian Arctic. We found 41 nests distributed among 10 islands in Karrak Lake; to our knowledge, this represents the largest number of king eider nests studied at one site.

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