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Distribution of marine birds in relation to water masses and fronts in the Strait of Belle Isle, northwestern Atlantic Ocean /LeGrow, Keith Herbert, January 1999 (has links)
Thesis (M. Sc.), Memorial University of Newfoundland, 1999. / Restricted until June 2000. Bibliography: p. 39-42.
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A comparative study of breeding ecology and timing in plankton-feeding alcids (Cychlorrhynchus and Aethia spp.) on St. Lawrence Island, Alaska.Sealy, Spencer George January 1968 (has links)
A comparative study of breeding ecology in Parakeet Auklets (Cychlorrhynchus psittacula (Pallas)), Crested Auklets (Aethia cristatella (Pallas)), and Least Auklets (A. pusilla (Pallas)) was conducted on St. Lawrence Island, Alaska, in 1966 and 1967. Emphasis was placed upon the climatic conditions which prevailed throughout the breeding seasons and their effects on timing of breeding in auklets.
The pre-egg stage, egg-laying and incubation, hatching, growth of young, and departure of chicks were studied in both seasons; 1966 was a late year and 1967 was an early year.
It was found that (1) Parakeet Auklets appear to have a more extensive migration than Aethia spp. , (2) arrival of adults back on the breeding grounds in spring occurs at approximately mid-May each year, (3) the pre-egg stage is prolonged but the post-breeding dispersal of adults and young from the nesting slope is rapid, (4) breeding does not take place at the same time each year, (5) Cychlorrhynchus breeds a few days later than Aethia spp., (6) a change in diet accompanies the onset of the chick-rearing period in Aethia spp. but not in Cychlorrhynchus, (7) patterns and rates of growth of A. pusilla chicks and possibly chicks of Cychlorrhynchus and A. cristatella differ according to time of hatching, (8) chicks of these auklets are well-adapted to early life, (9) predation upon auklets is low in the Sevuokuk colony, and (10) molt of adults overlaps the breeding effort in Aethia spp. but not in Cychlorrhynchus.
Ecological and behavioral specializations in the annual cycles of these auklets revealed close synchronization and shortening of breeding events necessary for breeding in the short Arctic summer. It appears that these auklets are faced with two problems in timing their breeding cycles. Breeding must take place within a period which is largely dictated by climate and they must make best use of the food supply. / Science, Faculty of / Zoology, Department of / Graduate
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Systematics and evolution of extinct and extant Pan-Alcidae (Aves, Charadriiformes) : combined phylogenetic analyses, divergence estimation, and paleoclimatic interactionsSmith, Neil Adam 24 October 2011 (has links)
Although the ecological interactions and ethology of the wing-propelled diving seabirds known as the Alcidae (Aves, Charadriiformes) have been intensively studied, systematic studies of the clade have been overwhelmingly limited to extant taxa. Pan-Alcidae have the richest fossil record among Charadriiformes, with specimens representing more than 35 million years of evolutionary history. Morphometric and apomorphy-based taxonomic revision of previously named extinct pan-alcids along with description of new species of extinct pan-alcids facilitated refined estimates of species richness. Combined phylogenetic analyses of morphological and molecular sequence data including pan-alcid fossils elucidated the poorly understood evolutionary history of the clade. Divergence estimation analysis for Charadriiformes placed previously hypothesized episodes of pan-alcid radiation and extinction in context with proposed paleoclimatic drivers of alcid evolution. / text
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Black Guillemots as indicators of change in the near-shore Arctic marine ecosystemHarter, B. Britten 14 September 2007 (has links)
This study attempted to explain an apparent inverse relationship between pack ice proximity and breeding success of Black Guillemots (Cepphus grylle) on Cooper Island, a barrier island in the western Beaufort Sea near Barrow, AK. I elucidated the first linear relationship between energy density and body size for the elusive Arctic Cod (Boreogadus saida). I discovered and ground-truthed the existence of previously unknown guillemot foraging habitat on small 50 m2 ice floes distant from the pack ice. I developed new daily metrics for quantifying the provisioning to linear (8 d – 18 d) and Post-Linear (19 d – fledge) chicks. I found daily consensus between Linear and Post-Linear chicks about the level of provisioning at the colony. Finally, I explained those daily changes with significant correlations with wind speed and direction. / October 2007
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Black Guillemots as indicators of change in the near-shore Arctic marine ecosystemHarter, B. Britten 14 September 2007 (has links)
This study attempted to explain an apparent inverse relationship between pack ice proximity and breeding success of Black Guillemots (Cepphus grylle) on Cooper Island, a barrier island in the western Beaufort Sea near Barrow, AK. I elucidated the first linear relationship between energy density and body size for the elusive Arctic Cod (Boreogadus saida). I discovered and ground-truthed the existence of previously unknown guillemot foraging habitat on small 50 m2 ice floes distant from the pack ice. I developed new daily metrics for quantifying the provisioning to linear (8 d – 18 d) and Post-Linear (19 d – fledge) chicks. I found daily consensus between Linear and Post-Linear chicks about the level of provisioning at the colony. Finally, I explained those daily changes with significant correlations with wind speed and direction.
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Black Guillemots as indicators of change in the near-shore Arctic marine ecosystemHarter, B. Britten 14 September 2007 (has links)
This study attempted to explain an apparent inverse relationship between pack ice proximity and breeding success of Black Guillemots (Cepphus grylle) on Cooper Island, a barrier island in the western Beaufort Sea near Barrow, AK. I elucidated the first linear relationship between energy density and body size for the elusive Arctic Cod (Boreogadus saida). I discovered and ground-truthed the existence of previously unknown guillemot foraging habitat on small 50 m2 ice floes distant from the pack ice. I developed new daily metrics for quantifying the provisioning to linear (8 d – 18 d) and Post-Linear (19 d – fledge) chicks. I found daily consensus between Linear and Post-Linear chicks about the level of provisioning at the colony. Finally, I explained those daily changes with significant correlations with wind speed and direction.
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Breeding ecology and nest site selection of Kittlitz's murrelets on Kodiak Island, AlaskaLawonn, Matthew James 14 December 2012 (has links)
The Kittlitz's murrelet (Brachyramphus brevirostris) is a rare member of the seabird family Alcidae that breeds in coastal areas of Alaska and Beringian Russia. The species belongs to the genus Brachyramphus, an unusual seabird taxon in which all three extant species nest non-colonially, situating their nests up to 75 km inland from coastal marine waters. This nesting strategy is different from that of most seabird species, which tend to nest colonially on remote islands or sea cliffs, where terrestrial predators are generally absent or cannot easily access nests. Within the genus Brachyramphus, Kittlitz's murrelet is notable because a majority of the global population appears to nest on the surface of the ground in rocky alpine habitat near inland or tidewater glaciers, foraging in adjacent marine waters influenced by glacial outflows. The unusual nesting habits of Kittlitz's murrelet have made the study of its nesting ecology difficult, and gaps therefore exist in our understanding of the species' breeding biology. Kittlitz's murrelet populations have declined substantially in core areas of its range, causing the U. S. Fish
and Wildlife Service to designate the species as a candidate for protection under the Endangered Species Act. A better understanding of Kittlitz's murrelet nesting ecology is crucial for determining potential causes of these declines and for future management of the species. To this end, I studied Kittlitz's murrelet breeding ecology and nest site selection during 2008-2011 on Kodiak Island, Alaska, in an unglaciated area that was recently found to have large numbers of accessible nests.
I and my colleagues found 53 active Kittlitz's murrelet nests in inland scree-dominated habitats and placed remote, motion-sensing cameras at 33 nests. Adults exchanged incubation duties at the nest every 24 or 48 h, almost exclusively during early morning twilight. Following hatching of eggs, parents provisioned their single nestling with an average of 3.9 to 4.8 fish per day, depending on the year. Parental visits to the nest during chick-rearing occurred primarily after sunrise in the early to mid-morning hours, and during evening twilight. Fish were delivered singly to the chick, and Pacific sand lance (Ammodytes hexapterus), a high-lipid forage fish, accounted for about 92% of all identifiable chick meal deliveries. Chick growth rates were high relative to confamilial species, consistent with the high quality of chick diets; the logistic growth rate constant (K) was 0.291, greater than that for any other semi-precocial alcid. Chicks fledged an average of 24.8 d after hatching and asymptotic chick body mass averaged about 135.5 g, approximately 58% of adult body mass. Age at fledging, asymptotic chick body mass (% adult mass), and the number of meal deliveries required to fledge a chick were all lower than or as low as any other species of semi-precocial alcid.
The average estimated nest survival rate during 2008-2011 was 0.093 (95% CI = 0.01–0.30), which is extremely low compared to other species in the family Alcidae, and is almost certainly insufficient to sustain a stable population. The primary causes of nest failure were depredation (47% of total nest fates), mostly by red foxes (Vulpes vulpes), and unexplained nestling mortality on the nest (21% of nest fates). Saxitoxin and/or pathogenic endoparasite burdens were observed in five of six necropsied chick carcasses, suggesting possible causes for chick mortality not directly attributable to predation.
Habitat characteristics of Kittlitz's murrelet nest sites differed significantly from unused sites at several scales. At a small scale (within 5 m of the nest), nest sites had a lower percent coverage of vegetation and higher percent coverage of intermediate-sized rocks (5–30 cm diameter), compared to randomly selected unused sites. Nest sites were also located on steeper, more north-facing slopes compared to randomly selected sites. Nest sites also had a lower percent coverage of vegetation than randomly-selected sites at larger scales (within 25 m and 50 m of the nest site). Nest sites were located significantly farther from the edge of densely-vegetated habitats than random sites. There was no evidence that nest sites were different from randomly-selected sites in terms of elevation, proximity to ridgelines, or proximity to the open ocean, although a low degree of variation within the study area for these habitat characteristics may have precluded detection of potential differences. Nest survival rates did not co-vary with slope, percent vegetation coverage, distance from vegetated edges, or percent cover of intermediate-sized rocks; however, this result may be an artifact of a limited sample size.
The results of this thesis will provide managers with a better understanding of the factors that may limit Kittlitz's murrelet nesting success, such as nest predation and forage fish availability, as well as factors that may influence the quality and distribution of Kittlitz’s murrelet nesting habitat in the future, given on-going and progressive climate change. / Graduation date: 2013
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