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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.
21

Factors affecting movement patterns of mule deer (Odocoileus hemionus) in southern Saskatchewan : implications for chronic wasting disease spread

04 1900 (has links)
Chronic wasting disease (CWD) has been a known threat to Saskatchewan’s wild cervid populations for more than a decade. As host movements can affect the spread of a disease across the landscape, disease models and management strategies should incorporate information regarding movement patterns of the host population in question. I used radio telemetry to study mule deer (Odocoileus hemionus) captured between 2006 and 2008 in a CWD-endemic region of southern Saskatchewan. Using location data from 152 individuals, I investigated home range size and patterns of direct and indirect contact (measured using proximity and shared space use) in relation to sex, habitat, and landscape structure. Home ranges (95% fixed kernel) of GPS-collared deer in this study averaged 21.4 km² (n = 94). Male home ranges (mean = 29.5 km², n = 56) were larger than those of females (mean = 16.1 km², n = 38), which could have implications for CWD prevalence differences between sexes. Of the landscape variables tested, topographic ruggedness was inversely related to home range size and Shannon’s diversity (a measure of both habitat richness and evenness) was positively related to home range size. Potential direct contact events were identified when two deer were located within 25 m of each other at the same point in time. These events occurred more often between February and April, agreeing with the tendency of mule deer to aggregate into large groups during the late winter months, and suggesting that this may be an important time period for disease transmission. Contact also occurred more than expected in cropland, whereas areas of shared use occurred more than expected in grassland, shrub/wood habitat, and rugged terrain. Smaller home ranges and greater degree of shared space use within areas of rough topography may lead to greater risk of environmental contamination with the infectious CWD agent in these areas. In contrast, the relationship between cropland and probability of direct contact may imply greater risk of direct CWD transmission between deer occupying this habitat. These results identify connections between particular landscape factors and risk of CWD transmission and will be used, in combination with results of related studies, to develop a model of CWD spread in Saskatchewan. This will in turn aid management agencies in developing methods to more effectively manage the disease and control its movement outside of affected regions.
22

Range limitations and phylogeography of stream salamanders in Quebec and Labrador

Markle, Tricia M. January 2006 (has links)
Physical barriers are known to limit species' ranges, but, in the absence of physical barriers, what prevents adaptation and expansion at the periphery? Genetic influence from central populations may prevent adaptation to ecological barriers by swamping peripheral populations with suboptimal genes. If this is the case, then isolation may enable local adaptation and further range expansion. Barriers such as rivers provide ideal tests of the influence of gene flow and may explain differences in range sizes. This study investigates northern range limitations and phylogeography of the Northern Two-lined ( Eurycea bislineata) and Northern Dusky (Desmognathus fuscus ) stream salamanders. Phylogeographic patterns of populations throughout Quebec and Labrador were investigated by sequencing portions of cytochrome b and 12S rRNA mitochondrial DNA genes. Interpopulation divergence was low for both species, however, unique genetic haplotypes and morphological variation on the north shore of the St. Lawrence indicate that the river is acting as a barrier to gene flow.
23

Feeding behaviour of Ateles belzebuth E. Geoffroy 1806 (Cebidae: Atelinae) in Tawadu Forest southern Venezuela

Amoroso, Castellanos Hernan Gerardo January 1995 (has links)
No description available.
24

Survivorship, habitat use, and movements for two species of mature forest birds

Vitz, Andrew C. January 2008 (has links)
Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 169-181).
25

Home-range fidelity and the effect of supplemental feeding on contact rates between white-tailed deer in southern Illinois

Rustand, Matthew Clifton 01 May 2010 (has links)
White-tailed deer (Odocoileous virginianus) are an important game animal and provide intrinsic value to many people. However, disease has become of great concern within white-tailed deer populations. Frequency of contract drives the establishment and spread of infectious diseases among susceptible hosts. Supplemental feed provided to increase white-tailed deer survival or create hunting opportunities, as well as bait stations to aid in capture of deer, may increase contact opportunities and disease transfer. My objective was to quantify the effects of bait sites on indirect contact between deer. I examined data from global positioning system (GPS) collars placed on 27 deer near Carbondale, Illinois, USA, from 2002 to 2005. Location data from GPS collars were used to ensure that I quantified contacts between deer in separate social groups, based on the volume of intersection of their spatial utilization distributions and correlation of movements. I matched 35 bait site locations and control sites not containing bait based on local land cover composition. Pairwise indirect contacts between deer were tabulated within a 10, 25, 50, 75, or 100-m buffer around each bait and control site. Indirect contact frequencies between bait and control sites were compared using mixed-model Poisson regression with deer pair as a random-effect variable and bait, joint utilization distribution (JUD), and year as fixed-effect variables. Contact frequencies did not differ significantly (P<0.05) between bait sites and control sites at any buffer distance, implying that small bait piles used to capture deer have minimal effect on contact frequencies. However, the effect of more consistent and greater quantities of food distributed during supplemental feeding programs should be studied further to determine its impact on contact rates and spatial distribution of deer. Understanding the spatial distribution of white-tailed deer is important to implement effective disease and population management within localized areas. The objective of this study was to measure the home-range fidelity of female deer in an exurban deer herd in southern Illinois. I compared location data of 7 deer that had been collected in 2004-2005 and 2008. I used the volume of intersection (VI) and percent of home range overlap to statistically compare the two annual home ranges for each deer. Deer were located used ground-based radiotelemetry and home ranges were characterized using a fixed kernel utilization distribution. Comparing home ranges between years, the mean VI was 0.45 with little variation (range 0.35-0.55). I found the mean percent overlap of 50% isopleths to be 47.1% (range 31.3-71.7%) and the mean overlap of 95% isopleths to be 62.0% (range 44.3-68.6%). My results indicate that female white-tailed deer on our study area showed strong home-range fidelity, which could permit disease and population management by removing deer and reducing local deer densities.
26

Population Demographics and Space Use of White-tailed Deer in the Northern Lower Peninsula of Michigan

Stroud, Janice Kay 01 January 2009 (has links)
I studied population demographics and space-use of white-tailed deer in Manistee and Mason counties in the northern lower peninsula of Michigan during 2005-08. Deer density from spring spotlight distance sampling surveys was 20.1 ± 1.7 deer/km2. The sex ratio was 14 bucks:100 does and the age ratio was 84 fawns:100 does. I radiomarked and monitored 105 does (62 adults and 43 fawns) for survival and space use. Annual adult survival was 0.74 ± 0.06, with most mortalities (n = 8 of 23) caused by human harvest. Adult survival was the highest during winter (1.00) and lowest in autumn (0.81 ± 0.08). Winter/spring fawn survival was 0.74 ± 0.06, with all mortalities caused by predation (n = 4) and starvation (n = 3). Mean size of composite home-ranges and core-areas were 2.0 ± 0.1 km2 and 0.4 ± 0.02 km2, respectively, and did not differ seasonally. Cover-type use did not differ seasonally between home ranges and core areas, indicating that deer did not select specific cover types within their home range. Vegetated openland and mast-producing upland forests received the highest proportion of use in home ranges (47% and 23%, respectively) and core areas (49% and 21%, respectively). These data will be beneficial for modeling deer population growth and response to harvest and to focus habitat management prescriptions for the Little River Band of Ottawa Indians.
27

Área de vida de Coryphaspiza melanotis e Cistothorus platensis no Brasil central e uma revisão sobre áreas de vida e territórios de aves na região Neotropical / Home range of Coryphaspiza melanotis and Cistothorus platensis in the central Brasil and a review of home ranges and territories of birds in the Neotropics

Aline Fujikawa 16 August 2011 (has links)
O Cerrado é a maior, a mais rica e a mais ameaçada savana tropical do mundo, com aproximadamente 80% da sua vegetação nativa convertida em áreas modificadas, como pastagem e agricultura (Myers et al. 2000, Silva e Bates 2002, Klink e Machado 2005). É considerado um dos 25 hotspots mundiais para a conservação da biodiversidade devido à excepcional concentração de espécies endêmicas, alta riqueza de espécies e, também, por estar sofrendo uma rápida perda de vegetação nativa (Myers et al. 2000). Nele, foram registradas mais de 856 espécies de aves, das quais 4,3% são endêmicas (Cavalcanti 1999, Silva e Bates 2002, Marini e Garcia 2005, Silva e Santos 2005). O Cerrado abriga 78% das espécies de aves de campos naturais que ocorrem no Brasil, e 41% do total relacionado para a América do Sul (Vickery et al. 1999). Apesar dessa importância, grandes áreas de campos nativos foram modificadas pela expansão da agricultura mecanizada de larga escala no Cerrado (Cavalcanti 1999). O desaparecimento dos campos naturais tem causado um declínio alarmante nas populações de aves dependentes destes hábitats (Stotz et al. 1996, Cavalcanti 1999, Vickery et al.1999). A alta diversidade de aves e o considerável impacto humano demandam a priorização de pesquisas para subsidiar as ações conservacionistas no Cerrado (Cavalcanti 1999, Cavalcanti e Joly 2002, Macedo 2002). Entre elas está a geração de conhecimento sobre aspectos da história natural das espécies, informações consideradas essenciais para o desenvolvimento de medidas apropriadas para a conservação (Macedo 2002, Podulka et al. 2004, Sutherland et al. 2004, Lopes e Marini 2005). Numerosas espécies de aves que ocorrem no Cerrado ainda têm sua biologia pouco conhecida (Macedo 2002). Como exemplo têm-se Coryphaspiza melanotis e Cistothorus platensis, espécies habitantes de campos naturais no Cerrado (Tubelis e Cavalcanti 2001, Macedo 2002), esta última, inclusive, considerada espécie ameaçada de extinção (IUCN 2009). As informações disponíveis são, principalmente, de caráter geral, descritas brevemente em livros de ornitologia abrangentes, como guias de identificação de espécies (Ridgely e Tudor 1994, Stotz et al. 1996, Sick 1997, Sigrist 2006), ou em trabalhos sobre comunidades de espécies de aves (e.g. Tubelis e Cavalcanti 2001). Assim, publicações específicas e detalhadas sobre a biologia de C. melanotis e C. platensis são importantes para se compreender a biologia das espécies, assim como para disponibilizar informações importantes para estratégias de conservação e manejo (Pyke et al. 1977, Develey e Stouffer 2001, Lopes e Marini 2006). A presente pesquisa visa trazer informações pioneiras sobre a área de vida destas espécies de aves. Pesquisas sobre áreas de vida e territórios têm sido realizados em todos os continentes, principalmente com aves e mamíferos (Laver e Kelly 2008). Sherril e Case (1980) notaram que os termos área de vida e território costumam ser usados de maneira similar pela maioria dos autores, embora tenham sentidos diferentes. A área de vida é a área total na qual um indivíduo de uma espécie particular vive, buscando alimento, parceiros sexuais e abrigo (Pyke et al. 1977, Rose 1982). Por outro lado, o território é a porção da área de vida defendida contra outros indivíduos da mesma espécie (Odum e Kuenzler 1955, Podulka et al. 2004). Apesar de diversos aspectos dos estudos de áreas de vida e territórios já terem sido revisados (Schoener 1968, Worton 1987, Harris 1990, Lawson e Rodgers 1997, Powell 2000, Laver e Kelly 2008) nenhum estudo revisou publicações sobre aves de um determinado continente ou região biogeográfica. Além disso, nenhuma revisão abrangeu aspectos gerais das metodologias de estudos sobre áreas de vida e territórios de aves. Ao reunir informações de estudos de área de vida e territórios de aves realizados na região Neotropical, este trabalho pretende apontar lacunas de conhecimento e sugestões para pesquisas futuras. / In the Cerrado, native grasslands have been rapidly destroyed, leading to alarming declines in the populations of birds that rely on these habitats. Grassland species such as Coryphaspiza melanotis and Cistothorus platensis remain poorly known. The study of home ranges and territories of birds is important to understand their biology and for their conservation. The objective of this study was to study home ranges of C. melanotis and C. platensis at Parque Nacional da Chapada dos Veadeiros, central Brazil. Ten males of C. melanotis were studied between February and December 2008. The mean sizes of home ranges were 4.47 ± 1.49 ha (Minimum Convex Poligon) and 3.48 ± 1.44 ha (Kernel 95%) and varied between the studied seasons. The home ranges of all studied individuals were overlapped to those of at least three co-specifics. Small and highly overlapped home ranges can be considered a positive aspect for the conservation of C. melanotis. This is because grassland fragments and small reserves could contribute substantially for the conservation of populations through the Cerrado extension. Fourteen males of C. platensis were studied between February and December 2008. However, only five individuals were observed during all the study period. The mean sizes of their annual home ranges were 6.10 ± 2.09 ha (Minimum Convex Poligon) and 4.57 ± 1.92 ha (Kernel 95%) and varied between the seasons. These birds were quite territorial, holding territories similar to their home ranges and with low overlap with male neighbors. Our results highlight the existence of great differences between populations of C. platensis found in temperate and tropical regions. Other objective of this thesis was to review studies of home ranges and territories of birds conducted in the Neotropical region. A total of 130 scientific articles published between 1960 and 2011, with study areas in 23 countries, were revised. Home ranges were examined in 64% of the studies, while 36% of them studied territories. In 95% of the revised publications, information essential for the conduction of data collection and analyses is lacking, making impossible the replication of the studies. The study of home ranges and territories was not among the main results of numerous publications, that investigated other aspects of the biology of neotropical birds. Among the suggestions for future studies is a better description of the methodologies.
28

Variabilita ve velikosti teritorií a domovských okrsků ptáků / Variability of home ranges and territory sizes in birds

Holubová, Kateřina January 2015 (has links)
Territories and home-ranges are the smallest spatial units of species' presence in a landscape and they determine in what ways and on what scales animals perceive and use their environments. Their sufficient sizes encompassing enough resources are critical for survival and reproduction of individuals. Processes and factors affecting territory and home-range sizes therefore belong to fundamental ecological issues. Despite its importance, the knowledge of variation in avian territory and home-range size at large spatial scales is poor. So far it has comprised mainly the findings that the used area is determined by individual's energetic demands, dependent on body size and diet type, and by environmental productivity. Therefore, the aim of this thesis was to use data gathered from available literature to describe the variation in territory and home-range size of birds. I was curious what was the nature of territory and home-range size frequency distribution; whether the sizes were species-specific and whether and how these sizes were affected (beside the body mass and diet type) by various environmental characteristics, such as latitude, temperature, precipitation, seasonality, altitude and habitat type. I have found that the territory and home-range size frequency distribution is approximately...
29

INFLUENCE OF LANDCOVER ON NORTHERN BOBWHITE HOME RANGE AND SURVIVAL AT MULTIPLE SCALES IN SOUTHERN ILLINOIS

Crawford, Caleb Stanley 01 September 2021 (has links)
Northern bobwhite (Colinus virginianus) populations have continually declined across much of their native range due to changes in land use and habitat. This notable decline causes concern for the future of this important game bird species and highlights the need for research on how habitat influences bobwhite vital rates. My research, conducted during 2018-2020 at Burning Star State Fish and Wildlife Area, addressed the following two objectives to provide information on how landcover characteristics influence bobwhite populations: (1) investigate how landcover characteristics influence annual bobwhite home range size, and (2) investigate how landcover characteristics influence bobwhite breeding season survival. For Objective 1, I radio-marked 113 individuals of which 50 bobwhites (31 males and 19 females) had ≥25 independent tracking locations and were used in my analyses. I modeled landcover types related to bobwhite habitat selection, habitat avoidance, foraging habitat, and protective cover to annual bobwhite home range size. Landcover types related to foraging habitat formed the most parsimonious model, with the proportion of grassland having the greatest negative influence on bobwhite home range size. As expected, landcover types that are thought to be beneficial to bobwhite fitness were negatively related to bobwhite home range size, suggesting those landcover types provide necessary resources for bobwhites throughout their full annual cycle. For Objective 2, I radio-marked 113 individuals of which 50 bobwhites (31 males and 19 females) had ≥25 independent tracking locations and were used in my analyses. I used a known fate model of the influence of landcover types, in a stepwise fashion, on bobwhite breeding season survival at two scales, home range and landscape. At the home range scale, the univariate model including early successional forest was the most parsimonious model, wherein the proportion of early successional forest negatively influenced bobwhite breeding season survival. Other competitive models included agriculture and early successional forest + scrub shrub where agriculture positively influenced breeding season survival while early successional forest and scrub shrub negatively influenced breeding season survival. The negative influence of landcover types thought to provide necessary protective cover for bobwhites on breeding season survival is inconsistent with the current paradigm that woody cover is an important habitat component that provides protective and escape cover, thermoregulatory functions, and midday loafing sites for bobwhites. Early successional forest provides visually appealing woody protective cover but appears to expose bobwhites to a higher predation risk because trees provide perch habitat for avian predators. Agriculture positively influenced breeding season survival because during the breeding season, agriculture provides overhead cover and bare ground that provides protective cover, foraging opportunities, and enables ease of movement. At the landscape scale, the null model was the most parsimonious model, but there was weak evidence that the proportion of grassland positively influenced breeding season survival. My study demonstrates how landcover composition influences annual home range size and breeding season survival at different scales.
30

The role of the ram in the impala (Aepyceros melampus) mating system

Oliver, Colin Malcolm 29 March 2005 (has links)
The role of territoriality was investigated using 25 impala rams in a site in South Africa. Field data were used to determine known rams as territorial and bachelors, as well as aspirant and indeterminate. The mean territorial tenure was 67.25 days, with a mean territory size of 21.0 ± 11.27 ha, compared to the home ranges of 34.1 ha ± 9.03 ha for territorial and 58.8 ha ± 33.35 ha for bachelor males. Territory boundaries seemed to remain constant through the season, and are smaller when bordering important features such as water holes, which appear to be neutral in terms of territoriality. Mating was observed on three separate dates between 16 May - 4 June 2001, three times by territorial males, the exception being an aspirant ram. The most important diurnal behaviour was feeding, followed by watching, walking, ruminating, resting and licking salt. It was found that bachelors browse more than territorial males, and all males browse and lick salt more in the non-rut. All rams were also more vigilant after lions were released. Only bachelors spar and allogroom, and they also orally groom themselves more than territorial males. Territorial males chase and roar more, and perform longer object aggression acts during the non-rut than bachelors. Other behaviours were rare or performed by all rams during the year. / Dissertation (MSc)--University of Pretoria, 2002. / Centre for Veterinary Wildlife Studies / MSc / Unrestricted

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