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 20 of 39 for “"Reproductive effort"”.
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The Meaning and Measurement of Reproductive Effort in Plants With Specific Reference to Agropyron Repens (Resource Allocation, Currency of Allocation, Allometry, Growth Analysis)
Reproductive effort, or the proportion of an organism's resources allocated to reproduction is a crucial aspect of an organism's life history and the optimal allocation of resources to reproduction in different environments has been the subject of much theorizing. Adequate tests of these theories …
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Influence of environmental variation on habitat selection, life history strategies and population dynamics of sympatric ptarmigan in the southern Yukon Territory
… suggesting a lower resilience to extend reproductive effort in colder years. White-tailed ptarmigan were also more likely to re-nest following failure and had higher daily nest survival, both of which contributed to greater annual productivity compared to rock ptarmigan. Annual adult …
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INDIVIDUAL AND ENVIRONMENTAL EFFECTS ON LIFE HISTORY TRAIT EXPRESSION IN NAZCA BOOBIES
… senescence should follow relatively high reproductive effort. In Nazca boobies, females recruit earlier and breed more often, predicting more intense actuarial and reproductive senescence in that sex. Females did show stronger senescence for survival and offspring production, but a causal …
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Drivers of reproductive variability in Vaccinium cespitosum and vaccinium vitis-idaea in northeastern Minnesota
Multiple factors affect reproductive variability within a population, and understanding these factors is important for making informed land management decisions. I investigated how clonality impacts reproductive variability in Vaccinium cespitosum and Vaccinium vitis-idaea (Ericaceae), and how the …
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Determinants and consequences of territory quality in the Bar-throated Apalis Apalis thoracica
… with consequent benefits in terms of higher reproductive success and/or chances of survival. The main aims of this study were: i) to determine the ecological factors influencing variation in territory size and quality among Bar-throated Apalises Apalis thoracica; ii) to investigate the …
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ΣΥΜΒΟΛΗ ΣΤΗ ΜΕΛΕΤΗ ΤΗΣ ΟΙΚΟΛΟΓΙΑΣ ΚΑΙ ΒΙΟΛΟΓΙΑΣ ΤΗΣ CALLIANASSA TYRRHENA (PETAGNA, 1792) (CRUSTACEA, DECOPODA, THALASSINIDEA)
… IN POPULATION DENSITY AND SEX-RATIO WHILE THE REPRODUCTIVE PERIOD AND MOLTING ACTIVITY OF THE POPULATION ARE SEASONALLY DETERMINED. THE SPECIES LIVE MORE THAN THREE YEARS AND IT IS ITEROPOROUS WITH REPRODUCTION STARTING BY THE COMPLETION OF THE FIRST YEAR. SEXUAL DIMORPHISM EXIST IN ABSOLUTE …
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Growth and Yield-Per-Recruit Modeling of Spot (<i>Leiostomus xanthurus</i>) in the Chesapeake Bay, and a Comparison of Biological Reference Points
… mortality (F), less than 20% of the potential reproductive effort of a cohort is available for spawning. Levels of F should be reduced to F = 1, to allow SPR = 20%. Levels of F should not, however, be reduced much below F = 1 to avoid under-utilizing the potential cohort biomass.</p>
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IMPACTS OF BLOODBORNE PATHOGEN INFECTIONS ON BREEDING ECOLOGY AND SUCCESS IN WHITE-THROATED SPARROWS (Zonotrichia albicollis)
… and fledging success. In species with multiple reproductive strategies, pathogen infections may have different impacts based on the role of the infected parent. White-throated Sparrows are a polymorphic species that mate disassortatively and display alternative reproductive strategies associated …
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An Ecosystem Model with Evolutionary Adaptive Trophic Structure
… to environmental cues is very limited. In an effort to capture the plasticity of life we present a new theoretical individual-based ecosystem model in the con- text of previous classical and experimental modelling approaches. The aim is to develop a deeper understanding of the factors …
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Regeneration mechanisms in Swamp Paperbark (Melaleuca ericifolia Sm.) and their implications for wetland rehabilitation
… out to determine the allocation of resources to reproductive effort and seed production in M. ericifolia. Comparative studies were carried out between two sympatric Melaleuca species with contrasting life histories and reproductive strategies (clonal vs. non-clonal) to determine if there were …
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The pre-reproductive period in a tropical bird: parental care, dispersal, survival, and avian life histories
… and life histories. Studies of the pre-reproductive period are particularly few in tropical regions, where the organization of life histories are predicted to differ compared to northern hemisphere species. For my dissertation I used radio-telemetry, mark-resighting, and field …
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Life history and microbiome analysis of freshwater fingernail clams (sphaeriidae) exposed to trace metal pollution
… interfaces. Previous work indicates that reproductive output is correlated with adult size in benign environments. Sampling four impacted and reference lake, which is not impacted by metal pollution, I measured clam somatic growth (adult shell length), brood production, tissue Cd levels, …
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Esforço reprodutivo de Mussismilia braziliensis (Verrill, 1868) (Cnidaria, Scleractinia, Mussidae) no complexo recifal dos Abrolhos, BA, Brasil
… located at different distances from the coast. Reproductive effort was estimated through fecundity (number of eggs per: polyp, cm 2, mesenteries and colony). A new staining method was used to ease identifying and counting eggs in the dissected polyps. The accuracy of the fecundity per gonad …
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The Evolution of Social Organisms: Modelling Reproduction Strategy
… to understand why an individual would reduce its reproductive success to invest instead in a higher reproductive process (i.e., reproduce collectively with other individuals). To address this problem, a method for studying reproduction strategy was developed and is presented in this thesis. The …
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Sex-specific investment in incubation and the reproductive biology of two tropical antbird species
… male versus female biparental incubation effort between two tropical antbird species in the northern Andes of Venezuela. We found that males and females apportion reproductive effort differently between these two species, but that male contributions of time and incubation effort were …
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Conservation genetics of sauger in the upper Missouri River drainage
… because their production represents wasted reproductive effort. Given my results, I recommend that (1) the transfer of genetically distinct stocks of sauger not take place; (2) historical levels of gene flow among populations be restored; and (3) the walleye fishery in the upper Missouri …
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Sex-specific investment in incubation and the reproductive biology of two tropical antbird species
… male versus female biparental incubation effort between two tropical antbird species in the northern Andes of Venezuela. We found that males and females apportion reproductive effort differently between these two species, but that male contributions of time and incubation effort were …
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Conservation genetics of sauger in the upper Missouri River drainage
… because their production represents wasted reproductive effort. Given my results, I recommend that (1) the transfer of genetically distinct stocks of sauger not take place; (2) historical levels of gene flow among populations be restored; and (3) the walleye fishery in the upper Missouri …
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Reproductive limitation in coastal ospreys (Pandion haliaetus): an ecological and an evolutionary perspective
… control that local food supply exerts on reproductive performance in these populations; (ii) how food limitation has ultimately shaped life-history patterns in this species, especially clutch-size and laying date. Reduced food delivery to nests increased nestling loss. Reproductive loss …
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Response of Vegetation and Endangered Waterbirds to Habitat Management Techniques at Kealia Pond National Wildlife Refuge
<p>Habitat selection, reproductive effort, and habitat utilization of Hawai’ian stilts (Himantopus mexicanus knudseni) and Hawai’ian coots (Fulica alai) was studied on Kealia Pond National Wildlife Refuge in Mau’i, Hawai’i. Nesting behavior was confirmed following management treatments on the …
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