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Bird populations of the Wasatch foothillsBerett, Delwyn G. 01 August 1958 (has links)
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.
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The value of using landsat 8 indices to describe large herbivore distributionMordecai, Kim Morag 19 September 2016 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in fulfillment of the requirements for the degree of Masters in Science. / Satellite imagery and remote sensing techniques provide a way to collect data over large temporal and spatial scales, and build indices that gauge ecological variables. These indices can explain the distribution of animals in their environment. In this study I compare the ability of various indices derived from Landsat 8, to reliably predict locations of different large herbivore species across diverse habitats. The study was undertaken in the Kgaswane Mountain Reserve, North West Province, South Africa. Daily locations of two herds of sable antelope (Hippotragus niger) and one herd of eland (Tragelaphus oryx) were used. One sable antelope herd (vlei herd) occupied a grassland plateau with a wetland and the other sable antelope herd (woodland herd), shared the wooded area at the base of the mountains with the eland herd. I described vegetation communities, burnt areas, geology and soil templates at animal locations during foraging bouts in the dry season; coinciding with the times of the Landsat images.
The overall aim of this study was to see whether an index or a combination of indices could better describe animal locations than the normally used NDVI. I calculated a number of indices, and compared their predictive ability to define areas used by the study animals. Specifically, I compared the Normalised Difference Vegetation Index (NDVI) to Soil Adjusted Vegetation Index (SAVI), Visible Atmospherically Resistant Index (VARIgreen), Green Atmospherically Resistant Index (GARI), Normalised Difference Water Index (NDWI), a proxy for soil moisture; and mineral composite indices assessing clay minerals, ferrous minerals and iron oxide. I chose these indices as they describe the basic characteristics of an ecologically functioning unit.
The locations of one of the sable antelope herds, located in grassland areas underlined by quartzite, were best described by NDVI, SAVI and VARIgreen. The locations of the other sable antelope herd, occurring in an open wooded area with shallow sandy soils on norite and quartzite, were best described by clay minerals and GARI. Eland locations, found in woodland areas characterised by deep norite soils, were best described by a combination of iron oxide, NDVI and SAVI.
Therefore, NDVI proved to be an adequate indicator in open grassland areas, where it could be interchanged with SAVI, and improved by VARIgreen. In closed woodlands NDVI, SAVI and NDWI could all be used to describe browser locations. NDVI was not a suitable index when it came to describe locations of a grazer in a woodland/grassland matrix. However, it is important to keep in mind that my results pertain only to one dry season and two herbivore species, and therefore further studies would be needed to be able to generalise the results further. / MT2016
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Patterns in the distribution and abundance of zebra mussels (Dreissena polymorpha) in the St. Lawrence River in relation to substrate and other physico-chemical factorsMellina, Eric January 1993 (has links)
No description available.
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Spatial distribution of rorqual whales in the Strait of Jacques Cartier, Gulf of St. Lawrence, Quebec, CanadaDoniol-Valcroze, Thomas January 2001 (has links)
No description available.
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The Population Dynamics and Distribution of Corbicula Manilensis (Philippi) in a Spring-fed Central Florida StreamGottfried, Peter K. 01 January 1979 (has links) (PDF)
Asiatic clams (Corbicula manilensis Philippi) were sampled at twelve stations randomly located along a 16-km stretch of the Wekiva River, Florida, every three months fro August 1976 to June 1977. Clams were found at most stations. Their abundance ranged from 4 to 1210 per m2. Mean numbers of Corbicula were highest at stations where the bottom sediments were primarily sand and lowest at stations where the bottom sediments were silt and decomposing organic matter. A linear relationship between water temperature, water depth, current velocity, total alkalinity, and pH, and the abundance and distribution of Corbicula was not evident. Seasonally, the abundance of Corbicula was highest in August 1976 and lowest in December 1976. The small size of the specimens suggest a recent invasion of Corbicula into the Wekiva River. The mean shell length of Corbicula in the river was 13.5 mm. The shell lengths of the largest clams ranged from 25.3 mm to 27.2 mm. Large clams were collected in December 1976 (mean shell length = 13.7 mm), whereas small clams were collected in March 1977 (mean shell length = 13.1 mm). Shell width and shell length were linearly correlated (r - 9.98 to 0.99), as were shell breadth and shell length (r = 0.96 to 0.99). The correlation between shell length and the number of rings on the shell was lower (r = 0.68 to 0.88). Clams with smaller rings (more rings per unit length) were found at downstream stations, where abundance was hing, whereas clams with larger rings (fewer rings per unit length) were found at upstream stations, where abundance was low. The data suggest that relationships between age and size depend on the habitat in which the organisms live.
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The postglacial dispersal of freshwater fishes in northern North AmericaMcPhail, John Donald January 1963 (has links)
No description available.
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Geographical variation and distribution of the Johnny darter (Boleosoma nigrum olmstedi) in Quebec.Hall, Charles Eric. January 1942 (has links)
No description available.
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Geographical variation in the genus Astarte (Phylum Mollusca: Class Bivalvia) from the Yorktown and Jackson Bluff formations (early Pliocene) of the Atlantic coastal plainMcKeever, Lauren Joann 15 July 2010 (has links)
Geographical variation in taxa must be considered in evolutionary studies. The purpose of the present study is to demonstrate how geographical variation can be measured and documented for a taxon for one slice of time. Future evolutionary studies should document geographical variation for the entire geographical range of the species involved at several points of time throughout its total stratigraphic range. Thus the variation that is present at one time horizon may be separated from the variation that occurs through time. This work consists of a study of geographical variation in the genus Astarte (Phylum Mollusca: Class Bivalvia) from the Yorktown and Jackson Bluff Formations (early Pliocene) of the Atlantic Coastal Plain. Factor analysis, multivariate analysis of variance, and discriminant analysis were performed on measurements of specimens of Astarte from ten localities. There are significant differences in the morphologies of individuals among localities. These differences are due to the presence of different species of Astarte and to variation in size and external ornamentation within the same species. Seven species recognized from literature on Pliocene Astarte were identified among the individuals of the ten localities, but the statistical results indicate that these seven species may be grouped into three "types" that mayor may not represent species. The three types occur together in some localities, suggesting that they are distinct species living in sympatry. Factors influencing geographical variation include larval dispersal strategy and the effect of the environment. / Master of Science
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Patterns of spatial variation : bacteria and tintinnids in the North Atlantic oceanManning, Jane Elizabeth January 2010 (has links)
No description available.
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Home on the range: spatial ecology of Atlantic spotted dolphins (Stenella frontalis) in the BahamasUnknown Date (has links)
I examined summer home range use of Altantic spotted dolphins in the Bahamas from 1991-2004. Home ranges for 86 dolphins using the 95% Fixed Kernel Density (FKD) estimator averages 62.o km2+=22.96 km2 and ranged from 24.8 km2 to 148.4 km2. Older animals and males had the largest ranges. Home range size did not vary with female reproductive status. core areas were defined by the 50% FKD contour and averaged 10.32 km2 +=5.47 km2. Habitat use was different between reproductive states for females. Non-reproductively active (NRA) females used deeped habitat. Behavioral use of the home range varied spatially. The core area was an important foraging area for males and reproductively active females. NRA females foraged more outside their core area compared to the core area. / by Bethany Augliere. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
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