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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.
1

Dispersion of the western winter wren (Troglodytes troglodytes pacificus [Baird]) in coastal western hemlock forest at the University of British Columbia Research Forest in south-western British Columbia

McLachlin, Roderick Archibald January 1983 (has links)
I studied the dispersion of winter wrens in 100-year-old, second-growth, coastal western hemlock forest at the University of British Columbia Research Forest in southwestern British Columbia from 1978-81. Male winter wrens were territorial on non-overlapping territories at an average density of 60 per km2. An average of 8% were polygamous. Females occupied generally non-overlapping home ranges at least during the breeding period, but were not shown territorial, although this possibility could not be excluded. Winter wrens were not uniformly distributed but showed differential use of various individual ecosystems (as mapped by Klinka 1976) and ecosystems grouped by forest floor habitats. Surplus, potentially territorial males were available during the breeding period which could have occupied the empty or sparsely occupied areas. Invertebrate food was more abundant in habitats used by winter wrens as compared to avoided habitats, and, food is proposed as a factor in habitat selection by winter wrens. I propose that winter wrens are spaced by territoriality and clumped by suitable habitat, and suggest that these two factors influence the patterns of dispersion of winter wrens in coastal western hemlock forest, and perhaps elsewhere as well. Klinka's ecosystems and grouped ecosystems were proposed as indicative of the distribution of winter wrens, and perhaps of other wildlife species generally. If so, ecosystems can arid should be used as the base for the study and management of wildlife in the province of British Columbia, and perhaps elsewhere as well. / Forestry, Faculty of / Graduate
2

An experimental analysis of juvenile survival and dispersal in snowshoe hares

Boutin, Stanley A. January 1983 (has links)
If spacing behaviour of snowshoe hares limits juvenile survival and recruitment during summer, removal of this behaviour should produce an increase in these parameters. During the summers of 1980 and 1981 I removed all adults from an 8 ha trapping grid and all first litter juveniles from another. Experiments were conducted in the southwestern Yukon during a period when hare populations were at peak densities. The experimental removals did not increase survival, but recruitment relative to control areas was higher to the adult removal grid in 1980 and to both the adult removal and juvenile removal grids in 1981. To determine whether juveniles trapped for the first time were residents or immigrants, I implanted adult females with, calcium-45. This was passed to nursing young and could be detected by scintillation counting of a sample of bone tissue taken from new recruits. Any juvenile without radioactive calcium was classed as an immigrant. The increase in recruitment on the removal areas was due to increased immigration. The number of resident recruits was equal on all study areas. Results support the hypothesis that spacing behaviour limits juvenile immigration but not survival. However, immigration to control areas was also high with immigrants making up 70% of the total number of juveniles present on the areas in October. If food limits snowshoe hare numbers, addition of food should lead to increased numbers through higher survival and immigration. If food supply influences spacing behaviour of hares, home range size should decrease with food addition. I supplied peak (1980) and declining (1981) hare populations on 8 ha grids (one in 1980 and 2 in 1981) with laboratory rabbit chow for 1 - 4 months during March through June. Population size was determined by live-trapping and movements of animals were monitored by radio telemetry. Food addition decreased weight loss and improved survival of hares in both years. Onset of breeding was advanced in males but not females. In 1980, the number of males on the food addition area was 1.4 times higher than those on the control area while the number of females did not differ. In 1981, numbers of males and females were up to 3.6 and 3.2 times higher respectively on the food addition area as compared to those on ;the control area. The differences were due mainly to increased immigration. Residents responded to food addition by decreasing home range size in 1980 but not in 1981. Movement of immigrants, as monitored by telemetry, to the food addition area indicated that some established home ranges there while others returned to their old home ranges. Results support the hypothesis that hare densities are limited by winter food supply during the early decline phase of the cycle and possibly during the peak phase as well. A decrease in home range size was not necessary for immigration to occur. To examine the relationship of dispersal to changes in snowshoe hare numbers, I monitored dispersal of hares during a population increase, peak, and early decline (1978-1982). Two methods were used: 1) a conventional removal grid in which all animals caught each trapping session were removed and 2) telemetry monitoring of radio-collared individuals. The number of animals caught on the removal area was correlated with density on the control area but per capita dispersal rate was not. Both the number of dispersers and the per capita dispersal rate were highest during the period of peak densities on the control area. Dispersal, as measured by the removal grid, was not density dependent. Only 23 of 265 radio-collared animals dispersed during the study. Dispersal accounted for an average of 11% of the losses of radio-collared animals during the population decline. Results from both telemetry and the removal grid indicated that the decline in hare numbers was not due to dispersal. The amount of dispersal as determined by the removal grid was much higher than that determined by telemetry. The difference was more pronounced during the population peak and early decline. This was due to the removal grid over-estimating the average amount of dispersal that was occurring because it attracted animals to it. These results point to the need to be more critical of the underlying assumptions of the removal grid method as a way of monitoring dispersal. / Science, Faculty of / Zoology, Department of / Graduate
3

A biogeographical study of currently identified Oregon pseudoscorpions with an emphasis on western Oregon forms

Benedict, Ellen Maring 01 January 1978 (has links)
The biogeography of the 50 currently identified Oregon species is reported from analyses of data from 2220 Berlese samples collected in a stratified, extensive sampling procedure, and from collection data on several hundred specimens from major private and public collections of pseudoscorpions. Individual species accounts including maps and data relating to geographical and seasonal distribution and habitats are provided, distributional areas and habitat types are categorized, dispersal mechanisms including examples of phoresy are presented and an illustrated key to Oregon species is given.
4

Distribution of marine zooplankton in coastal waters of Southern China.

January 1998 (has links)
by Tam, Pui Fun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 147-166). / Abstract also in Chinese. / List of Tables --- p.i / List of Figures --- p.ii / List of Plates --- p.v / Acknowledgements --- p.vi / Abstract (in English) --- p.vii / Abstract (in Chinese) --- p.ix / Chapter Chapter 1. --- General introduction --- p.1 / Chapter Chapter 2. --- Temporal and spatial distribution of Copepoda in the Zhujiang River estuary --- p.3 / Chapter 2.1 --- Literature review --- p.3 / Chapter 2.1.1 --- Physical properties of estuaries --- p.3 / Chapter 2.1.2 --- Factors affecting the zooplankton community --- p.4 / Chapter 2.1.2.1 --- Temperature --- p.4 / Chapter 2.1.2.2 --- River discharge and salinity --- p.5 / Chapter 2.1.2.3 --- Coastal hydrography --- p.6 / Chapter 2.1.2.4 --- Biological factors --- p.6 / Chapter 2.1.3 --- Site description of the Zhujiang River estuary --- p.7 / Chapter 2.2 --- Introduction --- p.9 / Chapter 2.3 --- Materials and methods --- p.10 / Chapter 2.4 --- Results --- p.13 / Chapter 2.4.1 --- Physical parameters and chlorophyll concentration --- p.13 / Chapter 2.4.2 --- Seasonal and spatial variations in the abundance of planktonic copepods --- p.17 / Chapter 2.4.3 --- Seasonal variations in the relative abundance of dominant copepods --- p.27 / Chapter 2.4.4 --- Relationship between copepod abundance and chlorophyll a concentration --- p.26 / Chapter 2.4.5 --- Seasonal and spatial distribution and salinity and temperature preference of dominant copepods --- p.30 / Chapter 2.5 --- Discussion --- p.41 / Chapter 2.5.1 --- Seasonal variations in copepod abundance --- p.41 / Chapter 2.5.2 --- Seasonal and spatial variations in species diversity --- p.43 / Chapter 2.5.3 --- Seasonal and spatial distribution of dominant species --- p.45 / Chapter 2.5.4 --- Seasonal succession and spatial segregation of dominant copepods --- p.51 / Chapter 2.5.5 --- Seasonal and spatial distribution of non-dominant copepods --- p.52 / Chapter 2.6 --- Conclusion --- p.60 / Chapter Chapter 3. --- "Spatial and temporal distribution of marine cladocerans in Tolo Harbour, Hong Kong" --- p.61 / Chapter 3.1 --- Literature review --- p.61 / Chapter 3.1.1 --- Geographical and seasonal distribution of marine cladocerans --- p.61 / Chapter 3.1.2 --- Vertical distribution --- p.65 / Chapter 3.1.2.1 --- Diel vertical migration --- p.65 / Chapter 3.1.2.2 --- Marine cladocerans as epiplankters --- p.68 / Chapter 3.1.2.3 --- Diel vertical distribution of marine cladocerans --- p.69 / Chapter 3.1.3 --- Horizontal distribution --- p.70 / Chapter 3.1.4 --- Reproduction --- p.71 / Chapter 3.1.5 --- Feeding --- p.72 / Chapter 3.1.5.1 --- Food composition --- p.72 / Chapter 3.1.5.2 --- Diel feeding behaviour --- p.74 / Chapter 3.16 --- Site description of Tolo Harbour --- p.77 / Chapter 3.2 --- Introduction --- p.79 / Chapter 3.3 --- Materials and methods --- p.80 / Chapter 3.3.1 --- Field sampling --- p.80 / Chapter 3.3.1.1 --- Physical parameters --- p.80 / Chapter 3.3.1.2 --- Ambient chlorophyll concentration --- p.82 / Chapter 3.3.1.3 --- Zooplankton sampling --- p.82 / Chapter 3.3.1.4 --- Gut pigment content --- p.83 / Chapter 3.3.2 --- Measurement of gut evacuation rate --- p.84 / Chapter 3.3.2.1 --- Gut evacuation rate --- p.85 / Chapter 3.3.2.2 --- Clearance rate --- p.86 / Chapter 3.3.3 --- Zooplankton distribution --- p.86 / Chapter 3.3.3.1 --- Quantitative analysis --- p.86 / Chapter 3.3.4 --- Statistical analysis --- p.92 / Chapter 3.3.4.1 --- Overall population --- p.92 / Chapter 3.3.4.2 --- Size --- p.93 / Chapter 3.3.4.3 --- Reproductive condition --- p.94 / Chapter 3.3.4.4 --- Gut pigment content and gut clearance rate --- p.95 / Chapter 3.4 --- Results --- p.96 / Chapter 3.4.1 --- Physical parameters and chlorophyll concentration --- p.96 / Chapter 3.4.2 --- Spatial and temporal distribution of marine cladocerans --- p.102 / Chapter 3.4.2.1 --- Species composition and abundance --- p.102 / Chapter 3.4.2.2 --- Vertical and horizontal distribution in general population --- p.105 / Chapter 3.4.2.3 --- Vertical and horizontal patterns in size distribution --- p.110 / Chapter 3.4.2.4 --- Distribution of marine cladocerans at different stages --- p.118 / Chapter 3.4.3 --- Feeding ecology of marine cladocerans --- p.125 / Chapter 3.4.3.1 --- Did variation in gut pigment content --- p.125 / Chapter 3.4.3.2 --- Gut evacuation rate --- p.125 / Chapter 3.4.3.3 --- Diel changes in clearance rate of Penilia avirostris --- p.129 / Chapter 3.5 --- Discussion --- p.132 / Chapter 3.5.1 --- "Diel vertical and horizontal distribution of 3 marine podonids: Pseudevadne tergestina, Podon sp. and Pleopis schmackeri" --- p.135 / Chapter 3.5.2 --- Diel vertical and horizontal distribution of Penilia avirostris --- p.138 / Chapter 3.5.3 --- Size distribution of marine cladocerans --- p.140 / Chapter 3.5.4 --- Feeding behaviour of marine cladocerans --- p.142 / Chapter 3.6 --- Conclusion --- p.145 / References --- p.147
5

Biogeography of the genus Sargassum (Heterokontophyta: Phaeophyceae) and the phylogeographic patterns of Sargassum spp. in Northwest Pacific. / CUHK electronic theses & dissertations collection / Digital dissertation consortium

January 2009 (has links)
The biogeographical pattern of the brown macroalgal genus Sargassum as well as the phylogeography of selected Sargassum spp. along NW Pacific coast were elucidated using analytical biogeographical and comparative phylogeographical tools. / To investigate the effect of freshwater outflow from Yangtze and Yellow Rivers in eastern China in shaping the genetic population structure of Sargassum spp., a comparative phylogeographic study was conducted on four closely related Sargassum species showing either continuous (Sargassum thunbergii and S. muticum ) or discontinuous (S. hemihyllum and S. fusiforme) distribution patterns along the Chinese coast. The results showed discontinuously distributed species to exhibit more haplotypes (e.g. four in TrnW_I spacer) among their populations than those with continuous distribution (two in TrnW_I spacer) pattern. Little or no population differentiation is revealed in species with a continuous distribution. Their occurrences in the brackish Bohai region may be attributed to the presence of inherited physiochemical traits that allow them to tolerate lower salinity waters in estuaries. The discontinuously distributed species, however, exhibited a deep genetic divergence among populations, as revealed by various genetic markers. There are two main lineages of S. fusiforme based on ITS2 and TrnW_I sequences, but the geographical region associated with this genetic break between the two lineages in eastern and southwestern Japan is different from that of S. hemiphyllum. Analysis of molecular variance (AMOVA) results indicate that the maintenance of the population structure of S. fusiforme appears not to be correlated with the outflow of the two rivers. For S. hemphyllum, reduced salinity as the suspected genetic barrier was investigated directly in the laboratory to elucidate its effect on the growth and survival of S. hemiphyllum var. chinense . Statistically significant difference was observed in the relative growth rate (calculated based on wet weight) of branches cultured under different salinities, with the optimal growth under salinity level of 33 ppt. The lethal limit of vegetative growth was between 0 and 10 ppt. Germlings cultured in 15 ppt attained the highest survivorship. The optimal growth of the germlings occurred at 25 ppt, while the lowest lethal limit was within the range of 0 ppt and 5 ppt. Germlings reared under low salinity were deficient in rhizoid development, making them highly unlikely to grow into large thallus in the natural environment with strong waves. Compared with the optimal and lethal salinity level of S. mutium, the lethal limits of both vegetative branches and germlings of the two species are comparable. The optimal growth of branches of S. muticum occurred under salinity level of 27 ppt, in contrast to the optimal salinity level of S. hemiphyllum at 33 ppt. This could have explained the absence of S. hemiphyllum in brackish water and support the suggestion that river discharge serves as a barrier for the exchange of genetic materials among its populations. (Abstract shortened by UMI.). / Two allopatrically distributed varieties of S. hemiphyllum, v. chinense and v. hemiphyllum, are genetically distinct in terms of their internal transcribed spacer 2 (ITS2) and Rubisco spacer. The genetic break between these two varieties, with v. chinense distributed in southern Chinese coast and v. hemiphyllum in Japan and Korea, is situated in a region that includes Bohai, Yellow Sea and East China Sea, all of which were heavily influenced by the Yangtze and Yellow Rivers in China. An introgression of the mitochondrial (Mt) genome from v. chinense to v. hemiphyllum, possibly mediated by the Kuroshio Current, is evident based on the Mt marker TrnW_I spacer. Hybridization between the two varieties may still be ongoing since the concerted evolution of ITS2 is not yet saturated in the Korean population located geographically in-between the distribution of the two varieties. In contrast, no variation in ITS2 and Rubisco spacer is revealed in S. muticum, including the native Asian populations and introduced populations in Europe and North America. There is a fixed one-nucleotide difference in the TrnW_I spacer, between the population in eastern Japan and all the other populations examined. This finding supports the earlier suggestion that the source of the introduced S. muticum populations is western and central Japan (Seto Inland Sea), where the germlings of S. muticum have been associated with the Pacific oysters previously introduced for farming in Canada, UK and France in earlier years. / Cheang, Chi Chiu. / Advisers: Put O. Ang; Ka-Hou Chu. / Source: Dissertation Abstracts International, Volume: 73-09(E), Section: B. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 221-247). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
6

The past and present geographical distribution of the Perissodactyla and artiodactyla in Southern Africa

Du Plessis, Sarel Francois 28 May 2008 (has links)
Please read the abstract in the section, 00front, of this document / Dissertation (MSc (Zoology))--University of Pretoria, 2008. / Zoology and Entomology / MSc / unrestricted
7

A REVISION OF THE TRIMYTINI OF AMERICA NORTH OF MEXICO (COLEOPTERA: TENEBRIONIDAE).

MacLachlan, William Bruce. January 1982 (has links)
No description available.
8

The local distribution and abundance of orb-web spiders

Lindley, Arthur January 1974 (has links)
No description available.
9

The social use of space : aspects of ecology, ethology and endocrinology in the ghost crabs Ocypode ceratophthalmus (Pallas) and Ocypode laevis Dana / Ecology, ethology and endocrinology in the ghost crabs

Lighter, Frederick John January 1977 (has links)
Typescript. / Bibliography: leaves 142-149. / Microfiche. / xi, 149 leaves ill
10

Development of widely adapted populations of maize (Zea mays L.)

Jimenez Miranda, Kenneth January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries

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