Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 26 for “"Non-breeding season"”.
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African penguin (Spheniscus demersus) distribution during the non-breeding season : preparation for, and recovery from, a moulting fast
… of the endangered African penguin during the non-breeding season. As foraging success during this period is critical to adult survival, this project explores their dispersal patterns, as well as the degree of overlap with commercial purse-seine fisheries which target the same prey. African …
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Rapid social regulation of 3β-HSD activity in the songbird brain
… with short-term aggressive challenges in many breeding vertebrates. However, some animals such as song sparrows (Melospiza melodia) are aggressive year-round, even during the non-breeding season, when gonads are regressed and systemic testosterone (T) levels are non-detectable. In contrast, …
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The relationships between gonadotropin-releasing hormone, luteinizing hormone, and testosterone secretion in the male sheep
… were examined in intact rams in May (during the non-breeding season), September (breeding season), and March (transition between breeding and non-breeding season). A very high coincidence between GnRH and LH pulses was observed in the ram across the season. Individual LH pulses in May and …
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Reproductive success and survival of the Common Grackle in central Illinois
… North America. However, based on North American Breeding Bird Survey data, the global population has exhibited a steady decline of -1.75% per year over the past 50 years and has suffered a cumulative loss of 58%. Understanding why the Common Grackle - a habitat and dietary generalist - is …
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Regulation of LH in the female common brushtail possum (Trichosurus vulpecula)
The seasonal control of reproduction, specifically the hypothalamic-pituitary-ovarian axis, has not been fully investigated in the common brushtail possum (Trichosurus vulpecula). This research aimed to characterise the control of pulsatile LH release and the seasonal change of LH in response to …
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Social and environmental causes and reproductive consequences of ornamented plumage in the Red-backed Fairywren (Malurus melanocephalus)
… typically exhibit ornamented red-black breeding plumage, but this species offers unique opportunities to test the mechanisms that maintain the honesty of ornamented plumage because three-quarters of all one-year-old Red-backed Fairywrens spend their first breeding season in unornamented, …
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The movement and landscape use of Blue Cranes in the Western Cape
… and distance travelled throughout the day of breeding and non-breeding cranes to determine whether the breeding status/season influences their ranging behaviour. There was no significant difference of the home range size between breeding cranes and non-breeding cranes (p > 0.05). There was …
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Effects Of Food Deprivation On Blood Lipid Concentration And Composition In Steller Sea Lions (eumetopias Jubatus)
… lions, the largest Otariid, fast during their breeding season; during this time they refrain from ingesting food for a period of 12-43 days. Fasting, while undertaking an extremely energetically demanding activity (breeding and pupping), requires specific physiological adaptations. This study …
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Female Social Rank and Steroid Production in Semi-Free Ranging Lemur Catta on St. Catherines Island, Georgia
… were found between female ranks during the non-breeding season. Future studies should focus on determining the possible sex differences in androgen-receptor abundance and sensitivity in this and other female-dominant species.</p>
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Investigations of delayed plumage maturation in the orchard oriole
… in which first year males possess a distinct non-definitive plumage. I used model/playback experiments to test predictions of alternative breeding season signaling hypotheses for DPM. I found that, contrary to the results of several previous studies, subadult plumage in the orchard oriole does …
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Movements and home range size of bald eagles from Glacier Bay National Park and Preserve, Alaska: with an analysis of satellite telemetry
… by homing and satellite telemetry. During the breeding season, the distances adult eagles moved from successful, unsuccessful, and mixed-success nests were not significantly different (£ = 0.148). Regardless of nest success, the proportion of adult eagle locations within 750 m of their nest …
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Relationships Between Winter Energetic Condition and Reproductive Investment in a Wild Bird
… studies often evaluate factors during breeding, but conditions outside of the breeding season may also play a role. These linkages across life history stages remain poorly understood, particularly at the mechanistic level. Using wild populations of black-capped chickadees (Poecile …
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Competition Between Fox (Sciurus Niger) and Gray (S. Carolinensis) Squirrels (Illinois, Habitat Selection, Behavior)
… to adult female gray squirrels during the breeding season but not during the non-breeding season. This difference provides a competitive mechanism to account for seasonal movements of gray squirrels. Gray squirrels were more efficient foragers than were fox squirrels, which may be a …
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Factors That Affect Harem Stability in a Feral Horse (Equus caballus) Population on Shackleford Banks island, NC
… Anecdotal evidence and an early study in the non-breeding season suggest that management of the Shackleford Banks island horses with immunocontraception reduces harem stability in the population, providing an opportunity to study the factors that influence harem stability. I investigated the …
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The macroecological distribution of avian functional diversity: environment, extinction risk and protected area coverage
… reveal the importance of migration (e.g. for breeding assemblages a positive association with temperature seasonality explains 6.7% of the variance in FD having accounted for species richness, whereas a negative association explains 21.4% for residents). This is further investigated by …
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How well do buffer circles capture the ranging behaviours of territorial raptors?
… to either abandon these sites, reduce their breeding productivity, or cause direct mortality to the territory holding birds. To mitigate such impacts, one method, employed as part of Environmental Impact Assessments (EIA), is the use buffer circles centred on nest sites. Within these buffers …
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Mister Parid's Neighborhood: Dispersal Behavior and Flocking Dynamics of the Social Black-crested Titmouse (Baeolophus atricristatus)
… atricristatus, hereafter BCTI) is a small, non-migratory passerine that has a tendency to form family flocking groups due to delayed juvenile dispersal each summer. A recently elevated species, separated from its sister-taxon, the tufted titmouse (Baeolophus bicolor), the BCTI is an ideal …
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Drivers of variation in the migration and foraging strategies of pelagic seabirds
… distances in order to take advantage of seasonality in resource availability or to avoid arduous winter conditions; however, this can be at a cost in terms of increased mortality. Indeed, anthropogenic threats in non-breeding areas are a major cause of population declines and a better …
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Characteristics, contexts, and possible functions of the vocalizations of Blue Jays
… types were used more often during either the breeding or non-breeding season and in certain behavioral contexts, suggesting that they served particular functions. However, most call types of adult Blue Jays were used throughout the year and in a variety of behavioral contexts, making it …
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Wintering white-throated sparrows (Zonotrichia albicollis): home ranges, aggression and corticosterone
… albicollis) are songbirds that spend the non-breeding season in southeastern North America, where they form philopatric territorial flocks. Flocks exhibit dominance hierarchies, with dominance rank associated with an individual's age and prior residence in the territory. Although social …
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