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 12 of 12 for “"biased sex ratio"”.
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Adamts9 is critical for the development of primary ovarian follicles
… Adamts9 KO zebrafish had a heavily male-biased sex ratio as 6–7-month-old adults, and female Adamts9 KOs were infertile. Furthermore, a novel intersex phenotype was also discovered in Adamts9 KOs zebrafish. These fish lacked clearly defined ovary or testis structure. To further understand …
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Sex-specific Habitat Use and Responses to Fragmentation in an Endemic Chameleon Fauna
… A recent field study reports a highly female-biased sex ratio in the Eastern Arc Endemic Usambara three horned chameleon, Trioceros deremensis, a large, sexually dimorphic species. This species is collected for the pet trade, and local collectors report males bring a higher price because only …
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Population dynamics and population genetics of the Critically Endangered Raso lark: implications for conservation
… a highly variable population size and a male-biased sex ratio in certain years. Using a dataset spanning 10 years, I estimated survival for both sexes to fluctuate between 0.76 and 0.94 over this period. This is much higher than the survival rate of its closest relative, the skylark. I also …
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Seasonal and Ontogenetic Changes in the Sex Ratio of a Population of Stinkpots (Kinosternidae: Sternotherus odoratus)
… hypotheses suggest turtle populations with biased sex ratios are the result of sampling errors such as improper sex determination, trapping bias, and behavioral differences between the sexes. This study was undertaken to determine if the observed sex ratio of a population of stinkpots …
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Cascading Effects Of Predator Removal On The Ecology Of Sea Turtle Nesting Beaches
… raccoon removal had created a significantly male-biased sex ratio in that population. I also examined the indirect effects of raccoon removal by comparing the abundances of raccoons and ghost crabs at four study sites using passive tracking plots. My data suggest intraguild predation by raccoons …
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The biology of Sassafras albidum (Nutt.) nees in regenerating upland hardwood stands in southwest Virginia following clear felling
… several sprouts. A comparison of the regeneration origin of sassafras stems growing on two sites with differing available soil moisture suggests that root sprouting was the dominant form of regeneration on dry sites, whereas on most sites root sprouting and seedling origin stem were present …
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Dioecious Plants: Evolution And Sex Ratio And Asepen Decline
… dioecious species are rare in nature, the sexual system appears in a diverse number of families and across all life forms and global locations. We looked at the population dynamics of natural populations to determine why many dioecious populations display biased sex ratios. We also looked …
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INDIVIDUAL AND ENVIRONMENTAL EFFECTS ON LIFE HISTORY TRAIT EXPRESSION IN NAZCA BOOBIES
… actuarial and reproductive senescence in that sex. Females did show stronger senescence for survival and offspring production, but a causal link between sex differences in early-reproduction and sex-differences in ageing was not supported because, within each sex, individual reproductive effort …
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Current status of the scale insect fauna of citrus in Tunisia and biological studies on Parlatoria ziziphi (Lucas)
… intrinsic rate of increase (rm), the mean generation time (T0) and the net reproduction ratio (R0)) of the black scale were assessed. From surveys conducted in the main citrus growing regions located in the northern part of Tunisia, a total of 84 samples were collected and over 200 …
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Combining natural enemies and selective pesticides in IPM programmes of exotic pests: the Tuta absoluta (Lepidoptera: Gelechiidae) case
… absoluta, fertility, longevity and also a male-biased sex-ratio of the progeny. In addition, demographic models developed by integrating possible sublethal effects of pesticides on B. nigricans life history traits, showed that biopesticides would strongly impact long-term population growth of …
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Deep water parapagurid hermit crabs: their distribution, abundance, population structure and associations in the Southern Benguela
… association. S. dimorphus to have a female-biased sex ratio of 1:1.5, and P. bouvieri of 1:1. The proportion of males in both species increased with cephalothoracic shield (CL) length. S. dimorphus males had positive allometric major right chelipeds, while P. bouvieri cheliped lengths were …
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Integrated pest management of the banana weevil, Cosmopolites sordidus (Germar), in South Africa
… independent location, or left in situ for the duration of the experiment. The ontogeny was determined by dissecting felled plants and toppled plants (up to 2-week-old fresh residues), and harvested plants visually classified as an early and a late rotting stage (decayed residues). Replicated, …