Thesis (M.S.) Zoology--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record.

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / Title from title screen (viewed June 2, 2009). Includes bibliographical references. Online version of print original.

Abstract During summer, May to September, of 2005, I examined nest-site selection and breeding ecology in a mixed-species colony of Roseate Terns (Sterna dougallii), Bridled Terns (Sterna anaethetus) and Black-naped (Sterna sumatrana) Terns on the islet of Jishan, Penghu, Taiwan. The aims are to identify characteristic differences of nest sites within the habitats, and to compare nest-site preferences of early- and late-nesting Roseate Terns. Significant interspecific differrences in nesting sites were found: Roseate Terns nested in areas with short vegetation and with higher nesting densities, Bridled Terns nested on screes, and Black-naped Terns nested on flat rocky surface. Hatching success was not correlated with site variables in Roseate Terns. Site characteristics of early- and late-nesting Roseate Tern nests differed. Late-nesting terns used sites with taller vegetation, less of walls around nests, fewer neighbors within 1 m, more nests on the edge of the subcolony, and with more visibility from 2 m compared with early-nesting terns. Human picking-up the eggs and typhoon appeared to be the major mortality factor on Jishan Islet. Roseate Terns with metal bands and leg-flags have been observed in the area. The results demonstrate that Roseate Terns tend to have a fidelity to a natal colony and some migrate to Australia for wintering.

Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are sagebrush obligates and are therefore considered to be key indicators of sagebrush ecosystem health. Sage-grouse populations have declined range-wide over the last century due to loss and fragmentation of sagebrush (Artemisia spp.) habitats. Sage-grouse populations found in large intact sagebrush landscapes are considered to be more resilient, however, some small isolated populations persist and thrive in fragmented landscapes. Because of Utah’s unique topography and geography, sage-grouse habitat is discontinuous and populations are naturally dispersed throughout the state in suitable intact blocks or in disconnected islands of sagebrush habitat. Thus, Utah populations provide the ideal place to understand how landscape attributes may influence at risk populations. Of these, the Morgan-Summit population is important because very little was known about the general ecology of this population and it experiences a high level of anthropogenic disturbances. I examined seasonal movement patterns, habitat selection, vital rates (nest initiation rates, nest success, clutch size, breeding success, brood success, and survival probability of breeding age birds) and the influence of vegetation components on vital rates of a small geographically isolated sage-grouse population in Morgan and Summit Counties in northern Utah from 2015–2016. To collect the data, I deployed 25 very-high frequency radio collars and 10 platform terminal transmitters and completed micro-site vegetation surveys at nest, brood, and paired random sites and then made comparisons. Nest sites exhibited variation in vegetation structure that influenced nest success, while brood sites did not. This population is one of the most productive in Utah exhibiting high nest initiation rates, hatching rates, and brood success rates despite limited habitat space and small seasonal movements. Transmitter type had no influence on vital rates, which is contrary to other studies, and limited influence on habitat selection. Sage-grouse avoided trees and developed areas, especially during the breeding season. Selection of other landscape variables was season-dependent. This information suggests that a sage-grouse population can occupy areas of limited habitat on an annual basis if seasonal habitat requirements are met. This study provides information that stake holders can utilize to conserve critical seasonal habitats within this study area where the population could be negatively affected by anthropogenic development pressure.

Populations of Lesser Sandhill Crane (Grus canadensis canadensis) have been increasing during the last decades in Eastern Siberia, an area historically known as breeding grounds of endangered Siberian Cranes (G. leucogeranus). Significant overlap in niche dimensions between the two species may occur and could lead to competition between them. Therefore, this study of comparative breeding ecology of common Lesser Sandhill Cranes and endangered Siberian Cranes was performed. From late May to early August 2000, I studied Lesser Sandhill and Siberian cranes within a 30,000-ha part of Kytalyk Resource Reserve in the Republic of Sakha (Yakutia), Russia. My main objective was to compare dispersion patterns and resource use of breeding Lesser Sandhill and Siberian cranes in areas of distribution overlap. Lesser Sandhill Cranes used moderate-wet (polygon) areas as their nest sites and main foraging areas, where terrestrial foods were scattered. In contrast, Siberian Cranes were nesting and foraging on low-basin wet areas, where aquatic foods were concentrated and dominant. Inter-nest distances were less for heterospecific cranes than for conspecific cranes, and more territorial behavior was projected toward conspecifics than toward heterospecifics. Lesser Sandhill Cranes were more mobile and used moderate-wet (polygon) areas more than Siberian Cranes; however, both species spent similar time foraging and being alert. The two crane species used different vegetation types for nesting and foraging, had different time-activity budgets, and used different resources in the Siberian tundra. While the population of Lesser Sandhill Cranes in the study area has the potential to increase, both species may simultaneously share the same geographic area due to differences in ecological requirements.

Forty-three and 54 Ferruginous hawk (Buteo regalis) pairs were found occupying territories in northern Utah and southeastern Idaho during 1972 and 1973, respectively. Of these 38 and 27 nesting pairs laid eggs. Nesting success was 77.1 percent in 1972 and 74.6 percent in 1973. for successful nests, an average of 2.9 and 2.6 young hatched and 2.7 and 2.3 young fledged during the respective years. This population is reproductively comparable to others in Utah and Colorado. Analysis of prey items collected from the nests indicated that black-tailed jack-rabbits (Lepus californicus) constitute 86 percent of the biomass (by weight) of three major prey species consumed by ferruginous hawks in this area. Jackrabbit density may be a major determinant of the number of young produced in a given year. Weight gained by the nestlings showed a marked sexual dimorphism. Female fledgelings weighed up to 1.43 times as much as males. Criteria were developed for sexing ferruginous hawks by measuring the diameter of the hallux. Mortality of 17 birds from the study area was recorded, of which 47 percent were immature birds. A total of 108 fledglings were banded and marked with color-coded patagial wing markers. Band reports of five (10 percent) of these birds were received. Utah juniper (Juniperus osteosperma) provided nest sites for 96.0 percent of the nests while three percent were built on the ground. Plant community types were determined at 63 nesting sites from aerial photographs. Dominant vegetation around nest sites were desert shrub types and crested wheatgrass (Agropyron cristatum) seedings. The possible impact of land management practices on ferruginous hawks is discussed.

Migratory animals face numerous challenges that are often exacerbated by climate change. In the Arctic, where climate change is occurring at 4x the average global rate, species must adapt rapidly to novel conditions. I studied four species of sea ducks (Long-tailed Ducks Clangula hyemalis and Steller’s Polysticta stelleri, Spectacled Somateria fischeri, and King Eiders S. spectabilis), of which Steller’s and Spectacled Eiders are federally Threatened, and all are well below historic population sizes. I conducted three studies to assess how female sea ducks interact with their habitats between arrival on the breeding grounds and nesting. First, I assessed patterns of occurrence within diverse tundra wetland types by female sea ducks, in relation to three metrics of wetland resource availability: wetland surface area and biomass in benthic cores and emergent sweeps separately. I also monitored activity budgets of female sea ducks. Wetlands containing the emergent grass Arctophila fulva were highly selected for by all species relative to the wetland surface area and biomasses of prey, while large lakes, streams, and wetlands lacking Arctophila were avoided. Most time was allocated towards foraging or loafing, emphasizing the importance of energy acquisition during this transitional time period following migration and prior to nesting. Wetlands selected for broadly across species are under threat as climate change reduces the prevalence of these wetland types on the landscape, requiring adaptation to such novel conditions. My second study assessed how sea ducks rely upon prey resources within tundra wetlands, and upon stored tissues acquired in marine habitats. Female sea ducks must both produce eggs and sustain themselves throughout a ~30-day period from egg-laying through hatch, with potentially different nutrient sources for each aspect of the reproductive process. I sampled stable isotopes of proteins in egg membranes (reproductive endpoint) and in red blood cells (body maintenance endpoint), which I modeled relative to stable isotopes in a suite of prey taxa from freshwater tundra ponds and marine habitats. Across all four species, most proteins came from tundra wetlands (≥ 89% of modeled protein sources) for egg production. Smaller-bodied long-tailed Ducks and Steller’s Eiders relied heavily on the local environment for body maintenance and survival (red blood cells) during incubation, but larger Spectacled and King Eiders only gained ~60% of proteins locally, relying on the remaining 40% from body tissues acquired previously from marine habitats. Local wetlands provided 60-99% of proteins for female sea ducks. Freshwater habitats in which sea ducks forage warrant protection, and conservation for some species requires interagency cooperation across tundra, freshwater wetlands, and marine habitats. My third study assessed patterns of nest site selection across species, years, and spatial scales. How females choose nest sites has major implications for population processes. Decisions integrate information across spatial scales for each component of habitat a hen considers. I used boosted regression trees (a machine learning technique) to model suitability of nesting habitat for 414 variables of habitat features at six spatial scales. Social association with other ducks were highly important in determining suitability. Suitable habitat varied spatiotemporally among species, but the relative amount of suitable habitat was consistent across years for each species. Conservation for suitable habitat must include broad areas to incorporate interannual variability. Through these three studies, I assessed the relative use of; importance of; and reliance upon various wetland types, the relative importance of marine versus freshwater nutrients for reproduction, and the factors driving nest site selection in a guild of sea ducks facing imminent climate change.

No description available.

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