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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

Laboratory investigations on Trichomonas gallinae with emphasis on diagnosis

Sannusi, Abdulrahim January 2011 (has links)
Digitized by Kansas Correctional Industries
262

Breeding habitat of Blue Crane (Anthropoides Paradiseus) in Mpumalanga Province, South Africa

Mmonoa, Ernest Mmaphuti January 2009 (has links)
Thesis (M.Sc. (Zoology)) --University of Limpopo, 2009 / The aim of this study was to determine the breeding habitat of Blue Crane (Anthropoides paradiseus) by investigating the home range, habitat selection and habitat suitability. Geographic Information System (GIS) was used as the main tool for analysis. Home range sizes of Blue Cranes were studied during the breeding season using direct observation method. A 50% and 95% Adaptive Kernel was used to estimate home range sizes. The home range sizes were 9.0 ha and 43.5 ha for 50% and 95% Adaptive Kernel, respectively. All the nests were located within 50% Adaptive Kernel, often referred to as core area. The nests were located in agricultural land (mainly pasture) and close to water sources. Habitat selection was studied at nest sites (n = 74) and random sites (n = 200) following site attribute design. The Blue Crane showed a preference to breed in agricultural lands, close proximity to water sources, higher elevation areas, within north eastern sandy highveld vegetation, and north facing slope. The Blue Crane also avoided anthropogenic factors such as built-up land, roads and railway line. ModelBuilder extension of ArcGIS software was used to construct a breeding habitat suitability model for Blue Cranes. Nine habitat variables (water source, slope, aspect, elevation, land use, vegetation, built-up land, roads and railway line) were used in the model. The model was constructed using reclassify and weighted overlay command. Highly suitable sites accounted for 601, 448 ha, while moderately suitable sites accounted for 823, 593 ha, and least suitable sites accounted for 3, 000, 153 ha. This study demonstrated the effective use of GIS technology in analysing the breeding ecology of Blue Crane. The GIS technology provided capabilities for capturing and analysing varied and large data. It was also evident that availability of accurate and complete species data remains vital to enable the full utilization of the GIS technology.
263

Ecology and feeding behaviour of the Arctic Skua (Stercorarius parasiticus Linnaeus) in Iceland

Arnason, Einar January 1974 (has links)
No description available.
264

Interactions among resident and migrant hummingbirds in Mexico

DesGranges, J.-L. January 1977 (has links)
No description available.
265

Comparative ecology, and conservation, of the Melithreptus genus in the Southern Mount Lofty Ranges, South Australia

Willoughby, Nigel January 2005 (has links)
The work presented in this thesis aimed to do the following : 1. investigate the cause of decline of the three Melithreptus species of the Mt Lofty Ranges, with a particular emphasis on M. gularis due to its critical status in the ranges ; 2. investigate the ecology and behaviour of sympatric M. brevirostris and M. lunatus populations in the Mt Lofty Ranges ; and 3. suggest management options for the three species. Further, it became clear through the course of the project that an understanding of the decline in Melithreptus required : 1. comparisons with other honeyeater species, particularly widespread and abundant honeyeater species. Three species of Melithreptus occur in the Mt Lofty Ranges : Brown - headed Honeyeater Melithreptus brevirostris ; White - naped Honeyeater Melithreptus lunatus ; and Black - chinned Honeyeater Melithreptus gularis. Since at least the 1970 ' s all three species have been in decline within the ranges. One species has been reduced in both abundance and distribution within the region ( M. gularis ), while the other two are now recognised as having reduced in abundance. Melithreptus species in the Mt Lofty Ranges are sympatric with strikingly similar ecology. Melithreptus gularis is the largest of the three, while M. brevirostris and M. lunatus are almost identical in weight, feeding behaviour and morphology. Despite their similarities no studies have closely examined their ecology in sympatry and no studies have examined possible causes of their decline. Interspecific competition is thought to be important in the organisation of honeyeater communities. Studies of nectarivore communities suggest a number of ways in which competition causes the component species to partition resources : size ; beak length ; habitat ; and behaviour, which includes a mix of social and feeding strategies. Due to its role in honeyeater community organisation, changed level of interspecific competition has been highlighted as a possible cause of decline in some honeyeater species in the woodlands of southern Australia. Both interference competition and exploitative competition have been highlighted in various situations ( Ford et al. 2001 ). Given the hypothesised role of interspecific competition in the decline of honeyeater species and the declining status of all the Melithreptus in the Mt Lofty Ranges the genus appeared to provide a good basis for examining the hypothesis that interspecific competition is contributing to the decline of some honeyeater species through exclusion from resources and / or reduction in resources available. ( Ford et al. 2001 ) give the following as potential tests for their interspecific competition hypothesis : 1. examine community structure for ' forbidden combinations ' ( pairs of species that rarely occur together ) ; 2. compare time spent in interspecific competition ( interference ), and foraging in fragmented and continuous habitat ; 3. measure seasonal and spatial patterns of resource abundance and depletion ; and 4. remove competitors and observe response in abundance and behaviour of other species. These suggestions form the basis for much of the work presented in this thesis. An initial survey examined not only community structure for forbidden combinations, but also investigated other possible causes of decline, based on literature for both declining woodland birds and Melithreptus. Besides interspecific competition, other possible causes included insufficient preferred habitat, insufficient food resources and landscape fragmentation. Repeated counts of honeyeaters at 90 sites of one hectare in the Mt Lofty Ranges were undertaken over a one year period. Melithreptus lunatus was found to be more abundant where certain eucalypt species occurred ( particularly E. viminalis ), although this was postulated to be a reflection of productive soils. Melithreptus brevirostris was found to be more abundant where Phylidonyris novaehollandiae ( New Holland Honeyeater ) was most abundant, despite P. novaehollandiae also being the most widespread and abundant honeyeater in the Mt Lofty Ranges. Thus, the survey work did not find forbidden combinations of honeyeaters. However , the scale at which the survey work was undertaken ( sites of 1ha ) may have masked any competition between species due to spatial heterogeneity. At the scale of one hectare there is likely to be areas of resource not used by other honeyeaters, allowing Melithreptus to avoid feeding territories of aggressive honeyeaters. Therefore, in order to more thoroughly investigate competition between P. novaehollandiae and Melithreptus, a removal experiment with finer resolution than 1ha was carried out. This demonstrated that P. novaehollandiae do prevent M. lunatus from using certain areas of the landscape. A final examination of interactions between Melithreptus and widespread and abundant honeyeaters was carried out in the form of a survey in which individual trees were watched and visits by honeyeater species timed. Based on observations of Melithreptus, it appeared that generally M. brevirostris groups used a swamping strategy to access defended resources, whereas M. lunatus moved quietly, often as individuals or pairs. Thus the two species were hypothesised to use two different behavioural strategies to access defended resources, termed stealth ( the use of secretive behaviour to access resources that are being protected ) and swamping ( the use of a combined direct approach by a number of individuals to access resources that are being protected ). Based on estimations of the standardised protection of resources for individual trees, M. lunatus were able to access defended resources for longer, while M. brevirostris were able to access better defended resources but for a shorter time. These results were consistent with the hypothesis of two different behavioural strategies for accessing defended resources. Both species may employ both strategies, but M. brevirostris more often use swamping, and M. lunatus more often use stealth. Investigating the morphology of the small honeyeaters of the Mt Lofty Ranges confirmed that size and beak length were important in discriminating between most species. However, these did not provide any basis for separating the Melithreptus. Closer examination of morphology between M. brevirostris and the M. lunatus sexes revealed further similarities to those previously documented. The average values for many morphological attributes of M. brevirostris fell between the average value for the M. lunatus sexes, suggesting that ecologically the three species / sexes formed a continuum. The M. lunatus sexes and M. brevirostris were then referred to as the small Melithreptus guild ( it was not possible to sex M. brevirostris based on the range of attributes measured ). The greatest differences between the small Melithreptus guild were found in wing length and leg morphology. The direction of the differences suggested that M. brevirostris would be more similar to female M. lunatus in movements and more similar to male M. lunatus in foraging behaviour. These two aspects of Melithreptus ecology were the subject of the last and most extensive phase of the project. Movements were investigated for Melithreptus at four sites in the Mt Lofty Ranges using radio - telemetry techniques. Melithreptus were found to use large areas of the landscape and to have large core areas of activity within their home range. Using the same methods confirmed that Melithreptus had larger home ranges ( mean 100 % minimum convex polygon 23 hectares ) than P. novaehollandiae ( mean 100 % MCP 5 hectares ), and larger home ranges than those reported in the literature for other honeyeater species. Data on a single M. gularis ( 100 % MCP 140 hectares ) suggest that this species has even larger home range requirements. Information from colour - banded birds suggests that most M. brevirostris and male M. lunatus had stable core areas of activity over the period of this study, while female M. lunatus were less likely to have stable core areas of activity, particularly during the non - breeding season. A trend in home range and movement data was consistent with the hypothesis that M. brevirostris was more similar to female M. lunatus than to male M. lunatus. Behaviour of Melithreptus and P. novaehollandiae were investigated using time budget techniques. Melithreptus were found to spend most of their day foraging ( up to 84 % ), very little time resting ( as little as 1.8 % ) and very little time in aggression ( as little as 0.6 % ). These values are each within the outer range of results published on other honeyeaters. Melithreptus gularis behaviour was very similar to both M. brevirostris and M. lunatus. Melithreptus appear to forage predominantly from poor quality resources, requiring a large proportion of their time allocated to foraging. The small proportion of time spent resting is probably a result of the time spent foraging. The small proportion of time spent in aggression is partly the result of a lack of aggression by Melithreptus, but is also potentially due to their knowledge of aggression levels within their home range and their use of stealth and swamping. Melithreptus are likely to avoid the most highly protected ( and therefore the most productive ) areas within their home ranges. A trend in behavioural data was consistent with the hypothesis that M. brevirostris was more similar to male M. lunatus than to female M. lunatus. Based on the data collected in this study, Melithreptus in the Mt Lofty Ranges are characterised by : relatively large home range size with core areas that are used over extended periods of time ; similar foraging behaviour and morphology ; lack of aggression ; and ( probably ( complex social behaviour. Their decline in the Mt Lofty Ranges can be attributed to the preferential clearance of their preferred habitat, their requirement for a large home range and their predominant use of poor quality resources, particularly in comparison to other, locally successful honeyeaters. The final aim of this work on Melithreptus honeyeaters in the Mt Lofty Ranges was to provide options for managing remaining Melithreptus populations, in particular M. gularis which according to informed observers is now critically endangered in the region. Due to the extent of habitat clearance in the Mt Lofty Ranges, the decline of Melithreptus will only be addressed in the long term through large scale revegetation projects. Melithreptus requirements in any large scale revegetation are most likely to be met by providing a range of eucalypt species. In the short to medium term, management actions may be needed to prevent the loss of M. gularis from the region. Given the findings of this study, there are few such options available. The management of woody weeds in known Melithreptus home ranges is suggested as one possible management strategy. Melithreptus rarely use a shrub layer for foraging, shelter or nesting, whereas P. novaehollandiae use a shrub layer for each of these activities. Thus, where grassy woodlands have been invaded by woody weeds, P. novaehollandiae potentially have an increased year round presence. / Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2005.
266

The Oregon big game resource : an economic evaluation /

Nawas, Farid Hassan. January 1972 (has links)
Thesis (Ph. D.)--Oregon State University, 1972. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
267

Avian responses to a gradient of urbanization in Seattle, Washington /

Penland, Stephen. January 1984 (has links)
Thesis (Ph. D.)--University of Washington, 1984. / Vita. Bibliography: leaves [167]-177.
268

The Fertilization and early development of the pigeon's egg ... /

Harper, Eugene Howard. January 1902 (has links)
Thesis (Ph. D.)--University of Chicago. / A Dissertation, submitted to the Faculties of the Graduate Schools of Arts, Literature, and Science, in Cadidacy for the Degree of Doctor of Philosophy. Includes bibliographical references (p. 34-36). Also available on the Internet. Also issued online.
269

Foraging ecology of wintering wading birds along the Gulf of Mexico coast

Sherry, Dawn Ann 25 April 2007 (has links)
I studied flock composition, distribution and foraging ecology of wintering wading birds along the Gulf of Mexico coast. I focused on geographic variability in wintering wading bird assemblages, the processes that structured these assemblages and habitat use by wading birds. I found considerable variation among three sites, Aransas National Wildlife Refuge (ANWR), Texas; Marsh Island Wildlife Refuge (MIWR), Louisiana; and Chassahowitzka National Wildlife Refuge (CNWR), Florida. Species comprising wintering wading bird assemblages varied regionally. ANWR had the most species-rich assemblage, with eight species. MIWR had only six wading bird species. And CNWR had only three different species. Processes that structured wintering wading bird assemblages also varied regionally. In ANWR, Texas, the Random Fraction niche apportionment model (RF model) best explained the empirical abundance data for ANWR. For abundance data from MIWR a good fit was obtained with the MacArthur Fraction (MF) model and the Power Fraction (PF) models. None of the models fully explained the CNWR abundance data. I also examined patterns of habitat partitioning among wintering wading birds at three different scales at two sites, Matagorda Island National Wildlife Refuge (MINWR) and Laguna Atascosa National Wildlife Refuge (LANWR). At the macrohabitat level, wintering wading birds showed interspecific differences in macrohabitat use of both open water habitats and vegetated flats. At the mesohabitat level all species at MINWR used the category nearest the edge most often, alternatively, at LANWR wading birds were most often in the mesohabitat category of 8.1- 12 m. from the edge. In both locations wading birds partitioned habitat based on water depth. Finally, I found that Great Egrets and Snowy Egrets participated more often in flock foraging and derived more benefits from feeding in flocks than other species. Great Egrets feeding in flocks had a higher mean strike rate than those foraging alone, whereas Snowy Egrets had a higher success rate foraging in flocks than those foraging alone. In the case of the darkercolored species (e.g., Great Blue Herons, etc.) they either showed no difference in behaviors between birds foraging in flocks versus those foraging alone or they actually did worse when they foraged in flocks.
270

Habitat use, nest success, and management recommendations for grassland birds of the Canaan Valley National Wildlife Refuge, West Virginia

Warren, Kelly A. January 2001 (has links)
Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xvi, 147 p. : ill. (some col.), col. map. Vita. Includes abstract. Includes bibliographical references.

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