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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.
61

A molecular phylogenetic investigation of the Staphyleaceae (DC.) Lindl. : with implications for its taxonomy and biogeography

Simmons, Sarah Louise 10 June 2011 (has links)
Not available / text
62

Changes in the distribution and abundance of North American breeding birds

Carrizo, Savrina Flora January 2012 (has links)
No description available.
63

Studies on the ecology and distribution of the marine shelled mollusca of Barbados.

Conde, Vincent Tomas. January 1966 (has links)
A considerable number of littoral and shallow water marine molluscs from the West Indian region and other areas reached Europe during the second half of the eighteenth and first half of the nineteenth century. These were, in many cases, brought by travelers and navigators and later described by European naturalists. Outstanding among these were Jean B. Lamarck, Carl von Linnaeus, J. F. Gmelin and Alcide d'Orbigny. Although they reported many species from the Lesser Antilles, very few are recorded from Barbados. [...]
64

The postglacial dispersal of freshwater fishes in northern North America.

McPhail, John Donald. January 1963 (has links)
Glaciated areas offer a unique opportunity to study the dispersal of animals. During glaciation the fauna of glaciated areas was either destroyed or forced into unglaciated refugia. When the icesheets retreated the glaciated regions were open to reinvasion. [...]
65

Chloroplast DNA diversity in Packera (asteraceae) : a phylogeographic study of Packera contermina and three related species from southwestern Alberta based on chloroplast DNA variation

Golden, Joanne L., University of Lethbridge. Faculty of Arts and Science January 1999 (has links)
Members of the genus Packera (Asteraceae) are widespread in North America, but most are found in western regions of the continent where extensive morphological integradation is common. Previous molecular systematic studies found that four species in southwestern Alberta, a region proposed to be at the interface of the Cordilleran and Laurentide ice sheets during the last advance of Pleistocene glaciation, showed unusually high levels of inter- and intrapopulational chloroplast DNA variation. The present study analyzed chloroplast haplotype phylogeny, frequency variation, and geographic distribution patterns in Packera contermina and closely related species P. pseudaurea, P. cana, and P. cymbalarioides from southwestern Alberta, nothern Montana, and northwestern Wyoming. Restriction site analyses of chloroplast DNA from 730 individuals across 34 populations of the four species revealed fifteen haplotypes, of which seven are commonly found in other North American Packera species. Three haplotypes were detected in P. cymbalarioides, seven in P. cana, eight in P. pseudaura, and twelve in P. contermina. The level of ahplotype frequency variation among populations was high in P. cymbalarioides (0=I) moderate to low in P. contermina (0=0.333) and P.cana (0=0.261), and very low in P.pseudaurea (0=0.085), possibly reflecting differences in the species' history. Phylogenetic analyses revealed 2 groups of haplotypes, one of which is found mainly in populations from the Great Basin of North America and the second in populations of more coastal and northern regions. The presence of haplotypes from both groups of Packera species suggests that the cpDNA diversity in southern Alberta arisen through hybridization/introgression events that have involved a number of species from outside of the region. / x, 81 leaves : ill., maps ; 28 cm.
66

Zoogeography and systematics of isopoda of the Beaufort Sea

Bray, Joseph Russell January 1962 (has links)
Isopoda are crustaceans which possess seven pairs of legs of about equal size, are flattened dorsoventrally and have no carapace. The thoracic limbs are without exopodites, pleopods are modified for respiration and the antennual exopodite is absent or minute. The isopods are a large group and exhibit much variety. They vary in size from two or three millimeters to several centimeters. A giant deep-sea form, Bathynomus giganteus, from the Gulf of Mexico and Indian Ocean, attains a length of 30 cm. and width of about 10 cc. The natural habitat of isopods is in salt and fresh water or in moist situations in the case of most terrestrial forms. They have been found in warm springs and subterranean streams (Richardson, 1905). [...]
67

Application of ultrasonic telemetry to movement of the graysby Cephalopholis cruentata in a marine reserve in St. Lucia, W.I.

Popple, Ian D. January 2001 (has links)
Ten individuals of Cephalopholis cruentata, a marine serranid common on Caribbean coral reefs and important to artisanal reef fisheries, were implanted with acoustic transmitters on two reefs within the Soufriere Marine Management Area, St. Lucia. The mean home range area determined was 2120m2. Home range shape was non-circular, with a mean aspect ratio of 0.72. Neither home range size nor home range shape differed between the study sites or as a function of fish size. However, more active fish, as determined by movement per hour and displacement per hour, had larger home ranges. / Use of space within the home range was characterised as activity rates (movement per hour), displacement rates (maximum distance between fish locations per hour), and preferential use of specific areas (% of position fixes in different areas). All fish demonstrated a clear preference for specific areas in their home range. Activity, displacement and % time spent in the preferred reef area were not correlated with fish size. Activity and displacement were higher by night than by day, and consistent with this, fish spent less time in their preferred home range area by night than by day. Given the home range size and movement patterns of C. cruentata determined in the study, the effectiveness of the marine reserve zones in the Soufriere Marine Management Area in protecting C. cruentata is assessed.
68

Distribution and morphometrics of South American dolphins of the genus Sotalia

Borobia, Mônica January 1989 (has links)
No description available.
69

Space use by vervet monkeys (Cercopithecus aethiops) and its consequences for the genetic structure of the Barbados population

Richardson, Karen S. January 1990 (has links)
The distribution of vervets in Barbados was not uniform across the island, vervets being more abundant in parishes with high vegetative cover and low human population density. Ranging patterns for 4 troops of vervets in Barbados were shown to be influenced by the maximum daily temperature and the mean daily humidity. The frequency of use of an area decreased with increasing distance from the sleeping site, and the duration of use increased with increasing distance from the sleeping site. An interpopulation comparison of home range size and ranging patterns of vervet populations from Africa and St. Kitts, showed a positive correlation between home range size and group size and a negative correlation between home range size and population density. / The genetic structure of the Barbados population was characterized by relatively high levels of heterozygosity and gene diversity at the group level, and small genetic distances between groups indicating adequate gene flow between groups. Three of the 6 polymorphic loci investigated showed differences in allele frequency between east and west sub-populations of vervets, indicating some genetic differentiation.
70

Ground dwelling beetle assemblages of remnant and created prairies of east-central Indiana

Brown, Angela M. January 2004 (has links)
Prairie restorations in east-central Indiana are commonly accomplished through purposeful planting of prairie vegetation, with the belief that prairie fauna will populate the planting independently at a later time. The objective of this study was to determine whether one assemblage, the ground dwelling beetles, would in fact re-populate tallgrass prairie restorations in a region where tallgrass prairie remnants are rare and highly fragmented. Two prairie remnants and five prairie plantings were sampled using pitfall traps from 21 May to 4 October 2003. Nine hundred forty-three beetles were collected, identified to family, and separated into morphospecies. Shannon diversity was greatest in the CR 575 E Cemetery prairie remnant, and increased linearly with increasing age in the created prairies, with the exception of the 1-year old prairie. TWINSPAN analysis grouped the two remnant prairies together in the first division, indicating that beetle assemblages of remnant prairies are more similar to each other than to created prairies. / Department of Biology

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