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Avian Thermoregulation In The Heat: Resting Metabolism, Evaporative Cooling And Limits To Activity In Sonoran Desert Birds, Eric Smith
Biology ETDs
Birds in subtropical deserts face significant thermoregulatory challenges as environmental temperatures regularly exceed avian body temperature. To understand the differing susceptibility of desert birds to increasing temperatures, this dissertation initially examined thermoregulatory performance in seven passerine bird species varying in body mass from 10 to 70g – Lesser Goldfinch, House Finch, Pyrrhuloxia, Cactus Wren, Northern Cardinal, Abert’s Towhee and Curve-billed Thrasher – and three larger Sonoran Desert nesting bird species – Mourning Dove (104 g), White-winged Dove (147 g) and Gambel’s Quail (161 g). Daytime resting metabolism, evaporative water loss and real-time body temperature were measured using flow-through respirometry at …
Constraints On Distributions And Diversity Of Birds And Mammals Over Variable Environments, Trevor S. Fristoe
Constraints On Distributions And Diversity Of Birds And Mammals Over Variable Environments, Trevor S. Fristoe
Biology ETDs
The distributions of species are determined by intrinsic factors such as physiological tolerances as well as extrinsic factors of the environment such as the availability of resources. While physiological tolerances generally change over evolutionary time scales, changes in environmental productivity due to processes such as succession or seasonal progression often occur over ecological times. I address both physiology and resource availability as drivers of the distributions and diversity of endothermic birds and mammals using a macroecological approach and a metabolic perspective. Migratory birds, altering communities over seasonal cycles, provide a unique opportunity to investigate the drivers of distributions and diversity …
The Effects Of Ecology And Evolution On Avian Flight Morphology, Natalie Wright
The Effects Of Ecology And Evolution On Avian Flight Morphology, Natalie Wright
Biology ETDs
The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight-genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production, or maneuverability that impinges on the physical genome? I measured genome sizes, wing dimensions, and heart, flight muscle, and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, I found that genome size was negatively …
Pre-Industrial Melanism: The Origin, Maintenance, And Genetic Basis Of An Urban Melanic Morph Of The Vermilion Flycatcher., Carl Jonathan Schmitt
Pre-Industrial Melanism: The Origin, Maintenance, And Genetic Basis Of An Urban Melanic Morph Of The Vermilion Flycatcher., Carl Jonathan Schmitt
Biology ETDs
Industrial melanism is a celebrated evolutionary phenomenon because it demonstrates the efficacy of natural selection in response to anthropogenic environmental change. We investigated a potential instance of industrial melanism in a vertebrate, the vermilion flycatcher (Pyrocephalus rubinus). The species is strikingly bright red throughout its broad range, but a sooty brown morph is abundant in the heavily polluted city of Lima, Peru. We found that plumage morph is perfectly predicted by a single nucleotide polymorphism in the MC1R gene. We quantified genotype and allele frequencies in seven neighborhoods of Lima. Within neighborhoods, there were fewer heterozygotes than expected, and surveys …