Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 31 for “"Distance sampling"”.
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Modeling Detection and Density Using Distance Sampling for Three Priority Grassland Bird Species in Texas - Northern Bobwhite (Colinus virginianus), Eastern Meadowlark (Sturnella magna), and Painted Bunting (Passerina ciris)
… and 5-minute point counts were performed using distance sampling protocols. Models were fit using gdistsamp from the package “unmarked” in R. Covariates that influenced detection for Northern Bobwhite were observer, ambient noise, time of day, and Julian date. Detection was higher later in the …
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Resource selection and abundance estimation of moose: Implications for caribou recovery in a human altered landscape
… bias. We evaluated the application of distance sampling as an alternative to SRB surveys, especially for use in caribou ranges. To correct for moose missed on the transect line, where a detection rate of 100% is critical, we developed a sightability model using 21 radio-collared moose. …
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Resource selection and abundance estimation of moose: Implications for caribou recovery in a human altered landscape
… bias. We evaluated the application of distance sampling as an alternative to SRB surveys, especially for use in caribou ranges. To correct for moose missed on the transect line, where a detection rate of 100% is critical, we developed a sightability model using 21 radio-collared moose. …
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The conservation ecology of the Dorcas gazelle (Gazella dorcas) in North East Libya
… using three distinct methods: questionnaires, a distance sampling field survey and genetic analysis. The findings from both the questionnaires and the field survey indicated that there had been a significant decrease in the population in the study area compared to historical records from the …
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ECOLOGY AND MANAGEMENT OF WHITE-TAILED DEER IN AN AGRICULTURAL LANDSCAPE: ANALYSES OF HUNTER EFFICIENCY, SURVEY METHODS, AND ECOLOGY
… counts, and thermal infrared imaging surveys. Distance sampling has shown great potential for estimating white-tailed deer density at a reduced cost relative to traditional survey techniques and may be useful within the agriculturally-dominated Midwest. Survival and dispersal rates are …
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Population Estimation Procedures For Elk and Deer in the Black Hills, South Dakota: Development of a Sightability Model and Spotlight Survey
… Applying the sightability model to a survey sampling procedure should allow for stronger inferences about the elk population in the Black Hills. Additional trials should be flown in no snow conditions to determine its effect on elk sightability. We also recommend further research into earth …
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Multiple-scale habitat models of benthic fish abundance in riffles
… Distributions of perpendicular sighting distances indicate models assuming equal sighting probability are not appropriate for benthic species but distance sampling models assuming decreased sighting probability with increased distance from observers provide reasonable alternatives. …
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Use and Survival of Greater Sage-Grouse in Meadows Managed for Non-Native Ungulate Grazing in Nevada
… hens at late brood-rearing habitat. I integrated distance sampling methods to simultaneously obtain data for estimating local population abundance and survival.In chapter 1, I used single-variate Cox proportional hazards models to investigate the effects of vegetative cover within the meadows on …
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The landscape ecology of brown hares and European rabbits in pastures in the north east of England
… to survey hares using night-time line transect distance sampling and compared this method with day time surveys. Night-time distance sampling produced improved precision estimates of hares with considerably less survey effort by maximising detectability during surveys. Hares and rabbits had …
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Passive Acoustics: A Multifaceted Tool for Marine Mammal Conservation
… blends the “snapshot” method and mark-recapture distance sampling, referred to here as (SMRDS). The cue-based methods were conventional distance sampling (CDS), an acoustic modeling approach involving the use of the passive sonar equation, and SECR. In the latter approach, detection probability …
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The Ecology of Large Marine Predators in the Hauraki Gulf
… to collect abundance data using mark-recapture distance sampling methods. Platform-of-opportunity and dedicated boat surveys were conducted during the same period to collect photo-identification data to estimate Bryde’s whale abundance with mark-recapture (MR) methods. Bryde’s whale abundance …
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Spatiotemporal Patterns and Drivers of Surface Water Quality and Landscape Change in a Semi-Arid, Southern African Savanna
… In Chapter 4, I evaluated the utility of Distance sampling methods to: 1) derive seasonal fecal loading estimates in national park and unprotected land; 2) provide a simple, standardized method to estimate riparian fecal loading for use in distributed hydrological water quality models; 3) …
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Ocorrência e uso de habitat da baleia-de-Bryde (Balaenoptera edeni Anderson, 1878) (Mammalia: Cetacea, Balaenopteridae) na região de ressurgência de Cabo Frio, RJ
… of this rorqual restricted to the tropics. The distance sampling method was used between 2000 and 2003, by the Grupo de Estudos de Mamíferos Marinhos da Região dos Lagos for monitoring cetaceans from a shore base, at Arraial do Cabo, southeastern of Brazil. Resulting of 2816h of effort with 203 …
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The Biodiversity Mirage: the Effects of Habitat Degradation and Exotic Predators on Ground-Dwelling Forest Birds, Tenrecs and Lemurs in Northeastern Madagascar
… from 2008 to 2013. Using camera trap surveys and distance sampling, we observed 26 bird species (n = 4,083 observations), three spiny tenrec species (n = 244 observations) and 12 lemur species (n = 1,172 observations). Out of 13 focal species (seven bird, three tenrec and three lemur species), …
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Some problems in the analysis of spatial pattern
… by point events in the plane, are proposed.Sampling a population in the plane is usually carried out using either quadrat counts or distance measurements. Only the latter are used in this Thesis, as the methods introduced are aimed at the plant biologist or forester studying patterns formed …
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Habitat, abundance and productivity of the Asian Houbara Chlamydotis macqueenii in Uzbekistan
… Spring fieldwork during 2012–2015 involved distance sampling, nest monitoring and habitat sampling across 14,500 km2 of the Kyzylkum Desert in Uzbekistan. Contrary to expectations, there appeared to be no negative landscape-scale association between livestock density and the abundance of …
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Encounters in the forest: Social and ecological dimensions of lemur hunting, habitat change and biodiversity conservation in south-east Madagascar
… affected by historic habitat degradation. Using distance sampling, I demonstrate lower abundance and group sizes of red-collared brown lemur and southern bamboo lemur under acute hunting conditions. Both species direct anti-predator behaviours towards humans and, in accordance with the ‘landscape …
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Investigating blue and fin whale populations through passive acoustic monitoring using ocean bottom seismometers
… the multipath ranging method and point-transect distance sampling methods to estimate fin whale call densities using OBSs deployed in the Marianas region. This chapter demonstrates the utility of single-OBS ranging for estimating populations through PAM. In Chapter 4, I employ a previously …
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Greater Galagos near Mt. Kasigau, Kenya: Population Density Estimates
… using line transects and analyzing results using Distance 6.0. These surveys were conducted during both dry and wet season and results were compared after the study. The second method was to trap individuals and use mark-recapture to determine population density. When caught in a trap, individuals …
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Characterization of Soundscapes in Shallow Water Habitats of the Florida Keys (USA) and Their Influence on the Settlement of Larval Fish and Invertebrates
… and (4) employ the passive sonar equation and distance sampling techniques to evaluate how the loss of large sponges affected the densities and abundances of snapping shrimp (Chapter 4).</p> <p>I found that near-shore habitats exhibit distinct soundscapes, that habitat degradation alters those …
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