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The Japanese Crested Murrelet Synthliboramphus wumizusume occupies a limited range in Southern Korea and Japan and is considered vulnerable by the IUCN. There is strong indication of a colony of Japanese Murrelets located in Kaminoseki, Japan; however, no nests or individuals have yet been found. The is also evidence that murrelets make use of this habitat during their vulnerable autumnal molting season during which they cannot fly. This habitat is threatened by the construction of a nuclear power plant in Tanoura Bay. Construction of this plant would result in loss of nesting sites, food supply, and other components vital to the survival of the colony. This study attempts to detect the presence of Japanese Murrelets in Kaminoseki using bioacoustic monitoring of songmeters placed around Tanoura Bay. Preliminary sonograms created using the R package “Bioacoustics” did not yield conclusive results regarding the presence of Japanese Murrelets as the program captured background noise but did not pick up on bird calls heard during manual playback of the WAV files. Further research must be completed to refine the settings used in the program in order to conduct a more definitive analysis of the dataset.

The demography of ovenbirds (<i>Seiurus aurocapillus</i>) was compared in landscapes highly fragmented by agriculture, moderately fragmented by commercial harvesting, and in contiguous boreal forest of Saskatchewan. Various survey techniques demonstrated that ovenbirds were less common in small, isolated forest patches in fragmented landscapes relative to contiguous forest. Male ovenbirds in fragmented landscapes (84 to 87% paired) had a lower probability of attracting females relative to males in contiguous forest (97%). Competition for territories was intense, as removal experiments demonstrated the presence of non-territorial male floaters. However, floaters were more common in contiguous forest, indicating this habitat was most preferred. Nesting success was lower in small farm fragments (29%) than the other landscapes (43 to 58%), due to high nest predation. Apparent annual survival of males was lower in small farm fragments (30%) relative to the other landscapes (57 to 60%). The difference in adult survival among landscapes was not caused by increased mortality in small farm fragments, but likely occurred because failed breeders (20% annual return rate) dispersed more than successful breeders (50%). Overall, small farm fragments were population sinks, where the number of adult birds lost to mortality and emigration exceeded the number of young produced. However, population size was constant over the length of the study indicating that populations in small farm fragments were rescued from extinction by immigration of birds from contiguous forest, where excess juveniles were produced. Populations in farm fragments were more likely to be rescued from local extinction by first time breeders (95% first time breeders) than the other landscapes (65 to 75%). <p>Increased turnover in small farm fragments, also resulted in a greater proportion of first time breeders (60%) in small farm fragments than the other landscapes (44 to 46%). These results support the idea that forest songbirds select habitat in a ideal preemptive manner. Younger individuals seem to be forced to settle in low-quality farm fragments, due to competition from older birds in the more optimal contiguous forest. Forest fragmentation bad a negative impact on ovenbirds and likely is an important factor influencing the decline of this and other Neotropical migrant species.

Successful foraging by avian predators is influenced largely by prey availability. In a large-scale experiment at the Loxahatchee Impoundment Landscape Assessment project within the Arthur R. Marshall Loxahatchee National Wildlife Refuge, I manipulated two components of prey availability, water depth and vegetation density (submerged aquatic vegetation and emergent vegetation), and quantified the response by wading birds in terms of foraging habitat selection and foraging success. Manly's standardized selection index showed that birds preferred shallow water and intermediate vegetation densities. However, the treatments had little effect on either individual capture rate or efficiency. This was a consistent pattern seen across multiple experiments. Birds selected for certain habitat features but accrued little benefit in terms of foraging success. I hypothesize that birds selected sites with shallow water and intermediate vegetation densities because they anticipated higher prey densities, but they did not experience it here because I controlled for prey density. / by Samantha Lantz. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

The first observations of Florida burrowing owls (Athene cunicularia floridana) occurred in the 19th century on historical dry prairie habitat in south central Florida. These early observations documented the ecology of burrowing owls in rural environments. Since then the vast majority of research on this subspecies has been undertaken in suburban and urban environments during the breeding period. The research undertaken on burrowing owls in suburban and urban environments includes determining natal dispersal distance, assessing female fecundity, mate fidelity, territory fidelity, date of juvenile and adult dispersal from breeding habitat, date of clutch initiation, nesting success, density of breeding pairs, causes of mortality, prey preference, and minimum annual survival of fledglings, juveniles, and adults. Very little research has been undertaken on burrowing owls in rural environments. The purpose of this thesis was to elucidate the behavior and ecology of burrowing owls in a rural environment. The topics researched in this thesis include home range in breeding habitat, dispersal distance to post-breeding habitat, location of post-breeding habitat, behavior during the breeding period, diet of rural versus urban owls, and the evaluation of three methods to trap burrowing owls. The results of this thesis indicate that, during the daytime, juvenile burrowing owls utilized habitat very close to the main and satellite burrows during the breeding period. At night juvenile owls foraged in an extensive saw palmetto patch surrounding the breeding habitat. The predominant prey of both rural and urban burrowing owls during the breeding period was insects. Dispersal of juvenile burrowing owls from breeding habitat coincided with the flooding of the breeding habitat during the rainy season.

Habitat selection theory presumes that organisms are not distributed randomly in their environments because of habitat-specific differences in reproductive success and survival; unfortunately, many previous studies were either unable or failed to look for evidence of processes shaping nest site selection patterns. Furthermore, little is known about adaptive nest site selection in northern environments where habitats often have little vegetation and time and climatic constraints may be pronounced. Therefore, I investigated patterns of nest site selection by common eider ducks (<i>Somateria mollissima</i>) at an island colony in Canadas Eastern Arctic, and looked for evidence of selective processes underlying these patterns by employing experimental and observational techniques.<p>I characterized physical features of (a) non-nest sites (b) active nest sites and (c) unoccupied nest sites that had been used in previous years. Habitat features that distinguished non-nest sites from unoccupied nest sites were also important in distinguishing between active and unoccupied nest sites during the breeding season. Active nest sites were closer to herring gull (<i>Larus argentatus</i>) nests, farther from the ocean and had organic substrates. In general, habitat features associated with nest use were not strongly associated with success after the onset of incubation. Nests near fresh water ponds were more successful in one study year, but in the other two study years successful nests were initiated earlier and more synchronously than were unsuccessful nests. Common eiders settled to nest first near the geographic centre of the colony, whereas sites near the largest fresh water pond were occupied later; distance to ocean had no observable effect on timing of nesting. Nest density was greater farther from the ocean, but timing of nest establishment did not differ between high and low density plots. <p>I tested whether moss or duck down placed in nest bowls could increase nest establishment, or advance laying date. I placed this extraneous material in bowls before nesting and found no difference in likelihood of nest establishment; however, bowls containing duck down were initiated earlier (or had higher survival) than those containing no nesting material. To investigate the role of nest shelter and microclimate in nest site choices and female body condition, I placed plywood nest shelters over established nests. Temperature probes indicated that artificially-sheltered females experienced more moderate thermal environments and maintained higher body weight during late incubation than did unsheltered females. However, few eiders nested at naturally-sheltered sites, possibly because nest concealment increases susceptibility to mammalian predators. My results suggest that eider nest choices likely reflect trade-offs among selective pressures that involve the local predator community, egg concealment, nest microclimate and energy use.

Habitat selection theory presumes that organisms are not distributed randomly in their environments because of habitat-specific differences in reproductive success and survival; unfortunately, many previous studies were either unable or failed to look for evidence of processes shaping nest site selection patterns. Furthermore, little is known about adaptive nest site selection in northern environments where habitats often have little vegetation and time and climatic constraints may be pronounced. Therefore, I investigated patterns of nest site selection by common eider ducks (<i>Somateria mollissima</i>) at an island colony in Canadas Eastern Arctic, and looked for evidence of selective processes underlying these patterns by employing experimental and observational techniques.<p>I characterized physical features of (a) non-nest sites (b) active nest sites and (c) unoccupied nest sites that had been used in previous years. Habitat features that distinguished non-nest sites from unoccupied nest sites were also important in distinguishing between active and unoccupied nest sites during the breeding season. Active nest sites were closer to herring gull (<i>Larus argentatus</i>) nests, farther from the ocean and had organic substrates. In general, habitat features associated with nest use were not strongly associated with success after the onset of incubation. Nests near fresh water ponds were more successful in one study year, but in the other two study years successful nests were initiated earlier and more synchronously than were unsuccessful nests. Common eiders settled to nest first near the geographic centre of the colony, whereas sites near the largest fresh water pond were occupied later; distance to ocean had no observable effect on timing of nesting. Nest density was greater farther from the ocean, but timing of nest establishment did not differ between high and low density plots. <p>I tested whether moss or duck down placed in nest bowls could increase nest establishment, or advance laying date. I placed this extraneous material in bowls before nesting and found no difference in likelihood of nest establishment; however, bowls containing duck down were initiated earlier (or had higher survival) than those containing no nesting material. To investigate the role of nest shelter and microclimate in nest site choices and female body condition, I placed plywood nest shelters over established nests. Temperature probes indicated that artificially-sheltered females experienced more moderate thermal environments and maintained higher body weight during late incubation than did unsheltered females. However, few eiders nested at naturally-sheltered sites, possibly because nest concealment increases susceptibility to mammalian predators. My results suggest that eider nest choices likely reflect trade-offs among selective pressures that involve the local predator community, egg concealment, nest microclimate and energy use.

Habitat selection research has focused on the role of vegetative and geologic habitat characteristics or antagonistic behavioral interactions. Conspecifics can confer information about habitat quality and provide positive density-dependent effects that may result in improved fitness, resulting in positive behavioral responses to conspecifics as a habitat selection strategy. I conducted 3 replicated, manipulative experiments to investigate use of conspecific cues in habitat selection for the golden-cheeked warbler (Dendroica chrysoparia) using simulated conspecific vocalizations during pre-settlement and post-breeding periods, across a range of woodland canopy cover. I measured territory density, pairing, and fledging success in paired treatment and control units. Territory density was >2 times higher in treatment units across the range of canopy (P = 0.02). Pairing success was positively correlated with territory density (P = 0.008). Territory density response was higher for pre-settlement than post-breeding treatment (P = 0.004). I found pre-settlement and post-breeding conspecific cues influence golden-cheeked warbler habitat selection, inducing settlement in previously unoccupied areas, and producing aggregations within areas of similar vegetative characteristics. Better understanding of social information use in habitat selection can improve our understanding of species distributions, yielding more accurate predictive distribution models; improve our ability to predict impacts of habitat changes on habitat use, survival, reproduction, and ultimately fitness; and provide a potential tool for attracting individuals to restored or managed sites.

My thesis focuses on different ranch management practices and the effects they may have on bird communities in northern Texas. Specifically, I address the potential differences between ranches enrolled in the Audubon Conservation Ranching program versus ranches that are not enrolled. Each research chapter is meant to be an individual publication. Chapter 2 compares and contrasts two different ways to survey bird communities in prairie systems. Chapter 3 compares ranch management techniques, prairie health indicators, and bird communities. This study aims to observe any mechanistic drivers of rangeland health that may elicit a positive bird assemblage response.

The full geographic distribution and habitat use of the Florida Burrowing Owl, a state "Species of Special Concern," is not well-understood, particularly in remote, non-urban areas. This thesis aimed to expand and improve knowledge about non-urban burrowing owls. We first compiled databases of historic sighting observations. Fieldwork verified and updated existing breeding observation point records and also yielded new breeding locations. Using a GIS, we characterized observed land use, landcover, relevant soil attributes, projected future land use and managed area status for selected points. We quantified landcover within biologically-determined buffer distances around burrows from our own field-verified records. Using standard resource selection methods, we compared observed and available proportions, calculated selection indices, and determined selection/avoidance for each landcover class. These empirical results were used in combination with expert opinion and literature review to finalize criteria for and map "suitable" landcover. Suitability of relevant soil attributes were also empirically-determined and used to further reduce the overall "suitable" area. The final suitable habitat maps appear to relate well to the overall distribution of known non-urban burrowing owl records and demonstrate that a great deal of potentially-suitable breeding habitat exists throughout Florida's central interior. Improved pasture, the most prevalent landcover class, also appears to be the most strongly selected in this study and may be of high importance to non-urban, breeding burrowing owls. Our results could be useful to wildlife officials managing this species. Recommendations include improving surveys and conservation efforts in non-urban areas and enhancing cooperation with landowners, particularly ranchers, as success on private lands seems critical to the long-term persistence of this species.