I studied the dispersion of winter wrens in 100-year-old, second-growth, coastal western hemlock forest at the University of British Columbia Research Forest in southwestern British Columbia from 1978-81. Male winter wrens were territorial on non-overlapping territories at an average density of 60 per km2. An average of 8% were polygamous. Females occupied generally non-overlapping home ranges at least during the breeding period, but were not shown territorial, although this possibility could not be excluded. Winter wrens were not uniformly distributed but showed differential use of various individual ecosystems (as mapped by Klinka 1976) and ecosystems grouped by forest floor habitats. Surplus, potentially territorial males were available during the breeding period which could have occupied the empty or sparsely occupied areas. Invertebrate food was more abundant in habitats used by winter wrens as compared to avoided habitats, and, food is proposed as a factor in habitat selection by winter wrens. I propose that winter wrens are spaced by territoriality and clumped by suitable habitat, and suggest that these two factors influence the patterns of dispersion of winter wrens in coastal western hemlock forest, and perhaps elsewhere as well. Klinka's ecosystems and grouped ecosystems were proposed as indicative of the distribution of winter wrens, and perhaps of other wildlife species generally. If so, ecosystems can arid should be used as the base for the study and management of wildlife in the province of British Columbia, and perhaps elsewhere as well. / Forestry, Faculty of / Graduate

One of the more interesting and unique of the natural habitats in the state of Utah is its chaparral zone, extending along the western foothills of the Wasatch Range. The purpose of this study has been to make an analysis of the bird population of this region in order to determine the comparative abundance of the species, their seasonal distribution within the area, and their ecological preferences.

The objectives of the study were to determine the year-round distribution and habitat selection of four marsh passerine species, as described by vegetation type and its physical characteristics, and to investigate interspecific competition as a factor in the habitat selection of the Long-billed Marsh Wren and the Red-winged Blackbird. Fulfillment of these objectives should help the B.C. Fish and Wildlife Branch to assess the effects of their management plans on marsh passerines. I determined the abundance of four passerine species in different vegetation types via marsh census transects over the period of one year. Nesting habitat and breeding information on marsh wrens and redwings was obtained via nest study plots. The results were: Areas traversed from the central and deepest marsh outward towards higher ground are inhabited by redwings, marsh wrens. Common Yellowthroats, and Song Sparrows, respectively. Habitats of wrens and redwings are spatially and temporally segregated. Wrens use the "Dense Spiraea" (Hardhack shrub) habitat extensively, while redwings use it hardly at all in the marsh. Similarly, redwings are abundant in Scirpus cyperinus (Hairy-seeded Bulrush), whereas wrens seldom use this habitat. Both wrens and redwings use other vegetation types, but redwings use them in the late spring, whereas wrens use them in the summer. Both wrens and redwings have lower reproductive success when nesting in close proximity than when nesting apart. This supports the hypothesis that interspecific competition exists and indicates that selection may favour habitat segregation. I also found mutual suppression of reproductive success when the effects of different vegetation types were removed. The results were not statistically significant however, possibly due to small sample sizes. Of the observed differences between the physical nest site parameters of wrens and redwings, vegetation height and presence and/or depth of water require further investigation as factors in the habitat selection of the two species. Bren-wren competition does not appear to affect wren nesting success in the present study marsh. Management recommendations are given based on the objective of maintaining and possibly enhancing bird species diversity in the study marsh. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

Despite increasing publicity, habitat loss and fragmentation remain a serious threat to biodiversity. The main objectives of this research were (i) to study the effects of forest fragmentation on the distribution and abundance of resident birds in the fragmented littoral forests of southeastern Madagascar and temperate woodlands of southeastern Australia at three spatial scales (patch, landscape and regional) and (ii) to place the results of these case studies within the realms of the equilibrium theory of island biogeography and its descendent theories, to ascertain whether it is appropriate to use these theories to derive conservation scenarios within these threatened regions. Deforestation of Madagascar's remaining forests is considered a global concern due to both its current high intensity and the small amount of forest claimed to be remaining on the island. Surprisingly, very few studies have considered the impacts of forest fragmentation on bird diversity in Madagascar. A multi-scale study on the effects of littoral forest fragmentation and degradation on birds is therefore a major step forward for bird conservation on the island. Furthermore, prior to this study no known work has been conducted on the avifauna within the threatened littoral forests of eastern Madagascar. My results indicated that (i) the littoral forests contained bird species assemblages that were unique when compared to neighbouring forest habitats, (ii) many forest-dependent bird species were significantly affected by habitat structure and especially proximity to forest edge and (iii) many forest-dependent species were affected by landscape factors such as remnant shape and remnant size. No relationship was found between measures of landscape composition, remnant 'isolation' and bird distribution within littoral forest remnants.

The first of five chapters describe the study area and study species, including a short description about the impetus for this research. The second chapter describes a unique hydrologic model for application in tidal ecosystems. The second chapter represents new information on the effects of various abiotic and biotic factors on foraging wading birds in this highly dynamic environment. The third chapter identifies important factors affecting the abundance of foraging wading birds in intertidal environments. The fourth chapter presents a study of the foraging habitat preferences of two wading bird species in intertidal environments. The fifth chapter describes a conceptual model of wading bird foraging ecology and a predictive model of foraging habitat in intertidal zones. The conceptual model captures the major drivers and linkages between the abiotic and biotic variables thought to affect wading bird foraging abundance in intertidal habitats. The conceptual model also identifies major knowledge gaps in our understanding of foraging ecology of wading birds in coastal intertidal areas. The predictive model of foraging habitat is meant to be used by resource managers, but its framework may be useful for ecological studies in general. The final and sixth chapter provides a summary of all the major findings. Each chapter has been written so as to be independent of the other chapters. As such, a full background, along with a discussion of the relevance of the chapter's findings is provided for each chapter. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Differences in patterns of species richness and taxonomic composition across continents are well documented. However, less is known about how these patterns originate from the fundamental processes that contribute to the assembly of continental biotas: speciation, extinction, immigration, and emigration. To truly decipher how these processes operate at a continental scale, it is crucial to understand how Earth-history events and environmental change shaped the biogeographical history of the taxa occurring in a region. The Pleistocene glacial cycles have been hypothesized to be a significant geological event which affected the Earth’s biota over the past three million years. During this period, multiple cycles, in which ice sheets covered a large portion of the Northern Hemisphere, have been hypothesized to facilitate allopatry and ecological differentiation. The central goal of this dissertation is to understand the assembly of continental biotas by integrating the role of Earth’s geological and environmental history and recent (late Quaternary) changes in distributions. Here, I studied the North American wood-warblers, which are passerine birds belonging to the family Parulidae. In the first chapter of this dissertation, I examined the extent to which recent diversification is underestimated by ignoring recently diverged taxa. To do so, I evaluated the effect of taxonomic delimitation on the inferred temporal patterns of diversification of wood-warblers in the genus Setophaga. My results show that species-level taxonomic delimitation in ecological and evolutionary studies is crucially important but is often ignored. Evaluating the effect of taxonomic delimitation in the genus Setophaga is particularly relevant because it has been widely cited as an ideal example of niche saturation, and previous studies suggested that lineages in this particular radiation exhibited an asymptotic accumulation of diversity through time. In this chapter, however, I demonstrate that this pattern was likely a consequence of the ways in which taxonomic diversity was sampled. In the second chapter, I examined how biotic and abiotic factors limit the distribution of species of the genus Oreothlypis at a continental scale. For most of the taxa examined, climatic- and biotic-based areas of suitability were equivalent, and therefore the relative importance of these factors could not be disentangled. However, in some cases, biotic variables limited the distribution in areas climatically suitable, and vice versa. The results of this chapter highlight the importance of considering potential effects of biotic interactions in the study of climate-driven range shifts. This paper is also an important methodological contribution to the general field of ecological niche modeling (ENM) by integrating climatic and palynological data to empirically estimate both abiotically and biotically suitable areas which that has only been done theoretically so far. In the third chapter, I integrated phylogenetic data, biotic and climatic ENMs, and reconstructions of environments during the LGM to test how cycles of fragmentation, differentiation, and expansion during the Pleistocene shaped the biogeographical patterns of the genus Oreothlypis in North America. Based on a time-calibrated phylogeny I identified two groups of taxa that diversified during the last million years and therefore were potentially affected by glacial cycles. My analyses suggest that there were rapid switches in the environmental conditions in which species of the genus occur and that glacial cycles resulted in dramatic range shifts from glacial maxima to interglacials. Distribution patterns during the LGM suggest that divergence in areas isolated by glaciers presumably contributed to the geographical structuring of Oreothlypis, as well as to their taxonomic and ecological diversity in the present. In summary, this work illustrates how wood-warblers are an ideal model system for examining the large-scale history of the North America biota and environment, particularly over the Pleistocene. They are highly diverse, have endemics in virtually all of North America's areas of endemism and ecosystems, and many of these patterns are repeated within and across clades. Furthermore, distributional patterns in warblers show high congruence with those of other organisms; thus inferences made about the history of this group likely have implications for understanding the biotic history of North America in general. In addition, many warblers have narrow ecological preferences in that they occupy forest environments with specific tree compositions. As a consequence, ecological models of their distributions, integrated with the North American pollen record of forest change, provide a new perspective on ecosystem change during glacial cycles, and its impact on the origin and maintenance of biodiversity in the continent.

No description available.

This thesis concerns a study into the relationship between vegetation structure and breeding birds in the dry subzone of the Interior Douglas fir BiogeocIimatic Zone. The study was conducted in the East Kootenay region of southeastern British Columbia. Studies of bird/habitat relationships often relate bird densities with successional vegetation; for management purposes it is convenient to view habitat alterations as changes from one successional stage to-another. Theoretical questions concerning the effect of succession and disturbance on species richness can be approached in this way. Also, there has been considerable interest in the effect of snags on bird density. An analysis of the effect of stumps and snags on bird density was incorporated into the study. Three questions guided the study: (1) What is the relationship between breeding birds and successional vegetation? (2) How is vegetation structure related to successional changes in bird species densities? (3) How does the number of stumps and snags affect the numbers of cavity nesting birds? There were two land management practices which altered the vegetation structure in the study area: selective logging and spring burning. This enabled me to determine the effects of these practices on breeding birds and to extend knowledge of the relationship between birds and vegetation structure. Twenty-four 300 yd by 400 yd (274 by 366 m) plots were established representing replications of each successional stage, transitions between successional stages, a selectively logged mature seral forest, a burned scrubby area, and a burned grassland/scrubby transition area. Bird data were recorded during fourteen, 20 minute visits to each plot in May and June of 1977. All birds detected by sight and sound were recorded during each visit to a plot. The vegetation data gathered on each plot included: estimates of the number of stumps and snags and estimates of crown coverage in each height zone of all species of grass, forb, shrub, and tree. The height zones recognized were 0-.5 m, .5-1 m, 1-10m, 10-24 m, and 24+ m. Multiple step-wise correlation was used to relate breeding bird densities with vegetation structure. Data from only the 25 most commonly recorded bird species were used to describe changes in the bird community with changes in vegetation succession. Results showed: (1) Bird species were non-randomly distributed with respect to successional stages. (2) Most successional stages support a unique compliment of bird species. (3) In general bird abundance was greater with greater successional age of a plot. However, dense stands of young conifer and climax Douglas fir forest had lower bird densities than the successional stages immediately preceding them. Mature serai ponderosa pine/Douglas fir forests had the highest bird densities. In some cases the bird densities on scrubby plots were comparable to the ponderosa pine/Douglas fir plots. (4) The relationship between bird species and vegetation structure is somewhat complex, but in general, visually obvious vegetation structures (i.e. height and coverage of grass, shrubs, and trees) are related to the presence of bird species. The species of trees and shrubs on a site can be used as an indicator of the bird species present. (5) The presence of cavity nesting birds was not closely linked with stumps and snags. Stumps and snags may not be a limiting resource. (6) The bird community on a grass dominated site which was burned in April 1977 was strikingly similar to that of another unburned grass dominated site. There were differences, among the bird communities on burned and unburned scrubby areas which were consistent with the recent fire history of the sites. (7) The selectively logged plot had numbers of bird species and bird species diversity similar to those of unlogged mature seral ponderosa pine/Douglas fir forest. The density of individual birds was lower on the logged plot than on the unlogged plots. Some bird species became more plentiful and others less plentiful as a result of the logging, but the bird community on the logged plot was composed of species associated with forested successional stages. A number of recommendations have been made for further study of East Kootenay bird/habitat interactions through a policy of experimental management. / Science, Faculty of / Zoology, Department of / Graduate

Relationships between the breeding bird populations of the southern Appalachian cove hardwood and mixed oak-pine habitat types were studied during the 1977 and 1978 breeding seasons, in Craig County, Virginia. Relationships between habitat structure and bird utilization for each of the 12 most common breeding species were also investigated. Bird and habitat data were collected within 100 meter x 50 meter transect areas. Eleven transects were located in the mixed oak-pine habitat and 8 in cove hardwood habitat. Relative density and species diversity of the 2 bird communities were essentially the same. Species composition was similar; however, relative dominance structures of the 2 communities were different. The blue-gray gnatcatcher (Polioptila caerulea), red-eyed vireo (Vireo olivaceus) and worm-eating warbler (Helmitheros vermivorus) exhibited a significant preference for the cove hardwood habitat. The ovenbird (Seiurus aurocapillus) exhibited a significant preference for the mixed oak-pine habitat, and the pine warbler (Dendroica pinus) and rufous-sided towhee (Pipilo erythrophthalmus) were observed exclusively in the mixed oak-pine areas. The relative density of the singing males was significantly greater in 1978 than in 1977. Multiple discriminant and regression analyses were used to analyze species/habitat associations. Eighty habitat components were considered for inclusion in these analyses. The "best" models derived for each species were presented and all were significant at the 0.05 level. Each species' association with the surrounding forest was best characterized by different combinations of habitat components, suggesting that resource division was adequately described through vegetative community structure. Research needs and potential uses for this type of data in nongame bird management were discussed. / Master of Science