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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.
31

Landscape-scale habitat use by greater sage-grouse in southern Idaho /

Shepherd, Jay F., January 1900 (has links)
Thesis (Ph. D.)--University of Idaho, 2006. / Abstract. "August 2006." Includes bibliographical references. Also available online in PDF format.
32

The effect of the resolution of topography description on 2-D modelling of river habitat

Kamps, Michael Christiaan January 2018 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Engineering Johannesburg, 2018 / The main objective of this report is to assess the effect of different topographic (elevation) data sources on river habitat modelling in low flow conditions. In the study, digital terrain models which consists of various datasets were assessed using 2-D hydraulic software models. The representation of the terrain was sourced from the following: airborne laser scanning, total station survey, a smartphone device and a handheld GPS device. From the results, which consisted of 4 simulations (discharges of 1.5 m3/s, 1 m3/s, 0.5 m3/s, and a field measurement of 0.3 m3/s) for each topographic dataset, the water level and velocity were derived and a comparison was made against the most accurate data set (total station survey). The comparisons included how each model was able to describe a habitat in terms of defined biotopes. This research proves that a total station survey is still the most accurate, however with the advancement in GPS technology a handheld GPS device has proven to be adequate for a desktop or intermediate study. In addition, a smartphone’s GPS tends to be more adequate for large surveys and inefficient for habitat modelling. / MT 2018
33

The ecological and evolutionary assembly of competitive communities in dynamic landscapes /

Pillay, Pradeep. January 2006 (has links)
No description available.
34

Habitat selection in small mammals with special reference to Rodentia and Insectivora : a study of an animal population

Evans, Francis C. January 1939 (has links)
No description available.
35

A spatial approach to statistical habitat suitability modeling: The Mt. Graham red squirrel case study.

Pereira, Jose Miguel Oliveira Cardoso. January 1989 (has links)
Multivariate statistical techniques were applied to the development of habitat suitability models for the Mt. Graham red squirrel, an endangered species. A digital map data base and a geographic information system (GIS) were used to support the analysis and provide input for two logistic multiple regression models. Squirrel presence/absence is the dichotomous dependent variable whose probability the models pretend to predict. Independent variables are a set of environmental factors in the first model, and locational variables in the second case, where a logistic trend surface was developed. Bayesian statistics were then used to integrate the models into a combined model. Potential habitat losses resulting from the development of an astronomical observatory were assessed using the environmental model and are found to represent about 3% of currently available habitat.
36

Wildlife resources of Kuwait: Historic trends and conservation potentials.

Alsdirawi, Fozia Abdul-aziz. January 1989 (has links)
Kuwait is an arid small country with a severe climate, but an interesting and diverse biological heritage. Historically Kuwait was the home for 28 mammalian, over 300 bird, and 40 reptilian species. Expanding human population and technology are increasingly altering Kuwait's natural habitat. Currently, 8 mammalian species are locally eradicated from Kuwait, but available elsewhere in the Arabian Peninsula. On the endangered list is 4 mammals, 5 birds. The status of most reptiles is unknown. A comprehensive overview of Kuwait's historic and contemporary wildlife is described. Major wildlife habitat types are identified and mapped. A conservation strategy addressing the wildlife and their habitats in Kuwait is suggested. The key to a successful strategy is habitat restoration and protection combined with legal protection of the wildlife. In addition, a program for re-introducing locally eradicated species to their historic range in Kuwait is suggested.
37

Manipulation of dung during feeding and nesting by dung beetles (Coleoptera: Scarabaeidae)

Madzivhe, Fhulufhedzani Macphee January 2017 (has links)
This dissertation was submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of Science / Dung beetle feeding is still not a widely understood behaviour. Feeding on the waste of other animals creates a challenge of acquiring the necessary nutrients for growth, development and for survival. Because of their soft mouthparts, it has always been thought that adult dung beetles cannot chew the hard parts of dung but only select smaller particles to feed on. Dung beetle larvae on the other hand can chew harder components, but where they get the nutrients required for development has not yet been discovered. The aim of this study was to discover which dung particles adult dung beetles select when feeding, and when creating a nest for their offspring, and also how much they can alter the dung nutrient content in the process. Foregut and hindgut contents were dissected out of the dung beetle Scarabaeus goryi, and their contents compared with untreated dung from the cow and the excreta of adult beetles. Brood balls and maternal gifts of Euoniticellus intermedius were also dissected. Nitrogen and carbon content, the carbon to nitrogen ratio, and results of the carbon and nitrogen stable isotopes were compared between all samples. When feeding dung beetles selected particles which were bigger than 800 μm in diameter and had three times more nitrogen than raw dung, and used particles over 2000 μm in size in the maternal gift packed for their offspring. Nitrogen content in the selected dung was increased from 1.40 % to 5.14% by adult dung beetle feeding and up to 2.62% in dung selected for the larvae to feed on. The carbon to nitrogen ratio also decreased when feeding adults and in the brood balls made for the larvae to feed on. Both carbon and nitrogen were absorbed from ingested dung during digestion. The heavier nitrogen isotope was selected for when feeding. The heavier nitrogen isotopes and the lighter carbon isotope were selected for during absorption. Dung beetles increase the nitrogen content of the dung on which they feed by careful selection of particles of a certain size and nitrogen content, which is probably the limiting nutrient when feeding and nesting. The increase in the nitrogen content is not only from the change in particle size but also in selection of particles with higher nitrogen content. / MT2018
38

Do zebra (Equus quagga) select for greener grass within the foraging area?

Boyers, Melinda 17 January 2012 (has links)
MSc., Faculty of Science, University of the Witwatersrand, 2011 / Spatial patterns in topography and forage distribution clearly determine large herbivore movements but our understanding of the foraging strategies that free-grazing herbivores adopt at different temporal and spatial scales is limited. Different foraging response patterns are displayed at different scales. Here fine-scale foraging strategies of Zebra (Equus quagga) were investigated by studying their selection for vegetation greenness in a Southern African savanna. Zebras have high-energy requirements thus the primary productivity and condition of the habitat plays an important role on their movements. Grass greenness was measured by Normalized Difference Vegetation Index (NDVI), a proxy for vegetation productivity and quality. Finer-scale studies are needed to understand the processes leading to a correlation between NDVI and herbivores performance. Data was collected at two different spatial scales, foraging area and feeding station. Food selection was recorded in relation to grass species and grass tuft greenness. Within the foraging area, grass species and greenness within zebra feeding stations were compared with random non used stations. Within the feeding station, species and greenness of grasses eaten by zebra were compared with those of grasses available but not eaten. Zebra selection was not consistent across scales. Although greenness was a factor in selection at feeding station levels and grass tuft levels; feeding station selection was limited to greenness due to season, and selection for species occurred only at the grass tuft level. However, zebra did select for the greener grass tufts within the feeding station even if it meant to eat ‘less palatable’ species (i.e. Eragrostis rigidior) instead of ‘very palatable’ species (i.e. Panicum maximum).
39

Movement, dispersal and interpreting health assessment parameters for free-ranging raptors and a reptile in a compromised estuarine ecosystem

Unknown Date (has links)
This investigation compared statistical parameters for the blood serum chemistries of free ranging Osprey nestlings from Florida Bay and an Osprey population from Lake Istokpoga, in Central Florida (Chapter 1). Florida Bay Ospreys showed higher mean rank values for alanine aminotransferase (H=6.79, P=.009), alkaline phosphatase (H=6.48, P=.011), and sodium (H=5.7, P=.017), and Central Florida had higher mean rank values potassium (H=13.19, P=.000) and carbon dioxide (H=6.23, P=.013). Serum chemistries values were also compared between free-ranging Bald Eagle and Osprey nestling in Florida Bay estuary in southern Florida (Chapter 2). There were significant differences between serum values of Bald Eagle and Osprey nestlings. Bald Eagle serum values were higher for total protein (H=17.833, P=.00002), Albumin (H=7.449, P=.006), Aspartate aminotransferase (H=113.153, P =.0001), and Calcium (H=7.148, P = 008). Osprey serum values were higher for alanine aminotransferase (H=11.824, P = 0.0005), alkaline phosphatase (H=105.5, P =.0001), creatine kinase (H=13.465, P = 0.0002), carbon dioxide (H=4.443, P = 0.035) and cholinesterase (H=99.3, P=.0001). Sixteen nestling Bald Eagles were fitted with satellite platform transmitter terminal (PTT) or VHF radio transmitter package for a duration of six years (Chapter 3)= to identify their movement and dispersal. One of the 15 eagles migrated to North Carolina, whereas the other 14 (93%) confined their movements to Florida. Tracking duration per individual ranged from 82 to 1,531 days. We estimated first-year survival as 52% and 67% for the period from 1.5 to 3 years. Diamondback Terrapins (Chapter 4) were evaluated by an integrated assessment of physical, chemical, and physiological parameters. Extreme site fidelity of the turtles to mangrove habitat was evident along with a strong female biased sex ratio. There was a significant difference in the total number of individuals collected at the two sites (P =. 01) despite the total size and shorelines of the two sites being very nearly the same. Total recapture rate was 70% for combined population (TLK = 80% and CKW = 48%). We provide blood serum values and microbial cultures as baselines from these turtles in the wild. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
40

Habitat selection among fishes and shrimp in the pelagic Sargassum community: the role of habitat architecture

Unknown Date (has links)
Pelagic Sargassum was used to determine the effects of habitat architecture for one species of shrimp (Leander tenuicornis) and two species of fish (Stephanolepis hispidus and Histrio histrio). Inter-thallus spacing (low, medium, and high) and depth (shallow versus deep) were manipulated independently to test whether the spatial components of habitat architecture. Two differing habitats (Sargassum versus seagrass species) were tested for the structural component of habitat architecture. There were no significant results for inter-thallus spacing experiments for L. tenuicornis and S. hispidus. H histrio selected habitats with medium inter-thallus spacing in two treatments. Large individual H. histrio contributed mostly to the significant effects. All three species selected habitats with a greater depth aspect. Finally, L. tenuicornis and H. histrio selected habitats with greater structural complexity (i.e., Sargassum). These results demonstrate clearly that habitat architecture of Sargassum influences habitat selection by these shrimp and fishes. / by Chelsea O. Bennice. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

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