Browsing by Author "Hill, Geoffrey"

Now showing items 1-20 of 24

Assessing Some Key Approaches Used to Monitor and Study Populations of Birds

McClure, Christopher (2012-01-10)

Efforts to monitor birds and determine their distributions often make assumptions that allow for inference into parameters of interest but necessitate that potentially confounding factors be ignored. In any scientific ...

Carotenoid-Based Dewlap Color as a Visual Signal in Social Communication of Brown Anoles (Norops sagrei)

Steffen, John (2007-12-15)

Carotenoids have been shown to be important integumentary coloring agents in many birds and fishes. The role of carotenoids as a prominent integumentary coloring agent of the dewlap has been noted in many Anoline lizards, ...

Changes in Concentrations of Heat Shock Protein 60, 70 and 90 of a Wild Songbird in Responses to Distinct Stress Challenges

Fu, Xiaoyu (2013-01-09)

Wild songbirds, such as the House Finch (Carpodacus mexicanus) require physiological mechanisms to maintain the homeostasis in face of stress threats. One of the primary mechanisms to protect system integrity is production ...

Characterizing the Chemical and Structural Basis of Animal Coloration from an Evolutionary Perspective

Justyn, Nicholas (2023-04-20)

Many questions regarding how animals produce their striking range of colors remain unanswered, particularly when pigments and structures are combined. In this dissertation, I completed four studies centered around ...

Condition Dependence and Status Signaling Function of Structural Coloration in the Eastern Bluebird (Sialia sialis)

Mercadante, Austin (2010-11-16)

I examined the relationship between blue feather coloration, nutritional condition, and status signaling in eastern bluebirds (Sialia sialis). I quantified nutritional condition by measuring growth rates of tail feathers ...

The Effect of Incubation Temperature on Sex and Morphology in the African Redhead Agama (Agama picticauda)

Steele, Ariel (2017-11-30)

The first demonstration of temperature-dependent sex determination (TSD) in a vertebrate was in the African redhead agama (Agama agama) nearly 50 years ago. The original study was generally overlooked until it was later ...

The Effect of Male Plumage Coloration on Parental Effort in Eastern Bluebirds (Sialia sialis)

Costantini, Maria (2013-07-15)

In iteroparous species, there is tradeoff between current and future reproductive investment. Parents that invest more in current offspring will provide resources that give those offspring better chances of survival and ...

Energetic tradeoffs between reproduction and longevity in the house mouse (Mus musculus)

Mowry, Annelise (2015-07-21)

Energy investment in reproduction comes at the cost of other life history traits, including future reproductive output and ultimately, lifespan. The disposable soma theory suggests that there is a negative relationship ...

Evolution of Pathogen-Induced Gene Expression in the House Finch, Carpodacus mexicanus

Balenger, Susan (2011-07-25)

Bacterial pathogens impact the survival, reproduction and fitness of their hosts making them extremely well-suited for experimental studies intended to understand adaptive phenotypic evolution of wild populations of ...

Evolutionary and physiological processes involved in carotenoid coloration in animals

Weaver, Ryan (2018-07-18)

Colorful animal ornaments have been a core research focus of the field of sexual selection in evolutionary biology, and carotenoid-based coloration has been particularly well-studied. Animals as diverse as fish, reptiles, ...

Exploring the role of carotenoid pigments in physiological function and color signals

Koch, Rebecca (2017-04-26)

The study of carotenoid-based coloration, particularly in bird species, is a large and growing literature that is increasingly defined by the framework of a single overarching concept, the resource tradeoff hypothesis. ...

Feathers at a fine scale

Shawkey, Matthew (2005-08-15)

In 1668, Antoine von Leeuwenhoek improved the crude microscopes that were being produced in Europe to better study small biological objects (Madigan et al. 1997). Although von Leeuwenhoek 's microscope revolutionized ...

Female Mating Preference and Reproductive Success in Eastern Bluebirds: Interacting Effects of Plumage Coloration and Genetic Compatibility

Liu, Mark (2009-12-18)

In my dissertation, I used a combination of aviary-based experiments, field experiments and correlational research to fully explore the importance of mate choice and environmental heterogeneity on reproductive success in ...

Fluctuating Asymmetry of White-Tailed Deer Antlers

deFreese, Rachel (2007-08-15)

Fluctuating asymmetry has been proposed as an indirect indicator of individual quality. Sexually selected traits, such as deer antlers, are expected to exhibit patterns of decreasing level of fluctuating asymmetry with ...

Intraspecific signaling functions of juvenal plumage

Ligon, Russell, A. (2009-04-22)

The function and evolution of avian plumage coloration has been the subject of many studies over the past decade, but virtually all of this research has focused on the plumages of sexually mature individuals. The color ...

Mating Behavior of Columbian Ground Squirrels

Manno, Theodore (2008-08-15)

Columbian ground squirrels (Spermophilus columbianus) are diurnal, herbivorous, colonial, and hibernatory rodents that reside in the Rocky Mountains of western North America. During April-July in 2005-2007, field assistants ...

The Physiological Effects of Bright Plumage Coloration

Huggins, Kristal (2008-08-15)

Songbirds with extensive, carotenoid-based plumage tend to maintain high levels of circulating carotenoids in plasma, which could represent a potential tradeoff between maintaining brightness at the expense of carotenoid-related ...

Plumage coloration and morphology in Chiroxiphia manakins: interacting effects of natural and sexual selection

Doucet, Stephanie (2006-05-15)

I examined how natural and sexual selection may have influenced the morphology and coloration of Chiroxiphia manakins (Aves: Pipridae). In the first chapter, I investigated age and sexrelated patterns of plumage coloration ...

The role of perennial hayfields in retaining predators

Grider, Amelia (2023-07-27) ETD File Embargoed

The United States has seen significant native grassland loss, with over 99% decline due to land use conversion to agriculture and industrialization, leading to declines in organisms that utilize grasslands. This is ...

Testing the Shared-Pathway Hypothesis through experimentation on the mating behavior, carotenoid biosynthesis, and mitochondrial function of Tigriopus californicus

Powers, Matthew (2022-07-13)

For decades, scientists have noted connections between individual condition and carotenoid-based coloration in terrestrial and aquatic animals. Organisms that produce more vibrant carotenoid-based coloration tend to have ...