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Description
Urbanization exposes wildlife to many unfamiliar environmental conditions, including the presence of novel structures and food sources. Adapting to or thriving within such anthropogenic modifications may involve cognitive skills, whereby animals come to solve novel problems while navigating, foraging, etc. The increased presence of humans in urban areas is an additional environmental challenge that may potentially impact cognitive performance in wildlife. To date, there has been little experimental investigation into how human disturbance affects problem solving in animals from urban and rural areas. Urban animals may show superior cognitive performance in the face of human disturbance, due to familiarity with benign human presence, or rural animals may show greater cognitive performance in response to the heightened stress of unfamiliar human presence. Here, I studied the relationship between human disturbance, urbanization, and the ability to solve a novel foraging problem in wild-caught juvenile house finches (Haemorhous mexicanus). This songbird is a successful urban dweller and native to the deserts of the southwestern United States. In captivity, finches captured from both urban and rural populations were presented with a novel foraging task (sliding a lid covering their typical food dish) and then exposed to regular periods of high or low human disturbance over several weeks before they were again presented with the task. I found that rural birds exposed to frequent human disturbance showed reduced task performance compared to human-disturbed urban finches. This result is consistent with the hypothesis that acclimation to human presence protects urban birds from reduced cognition, unlike rural birds. Some behaviors related to solving the problem (e.g. pecking at and eying the dish) also differed between urban and rural finches, possibly indicating that urban birds were less neophobic and more exploratory than rural ones. However, these results were unclear. Overall, these findings suggest that urbanization and acclimation to human presence can strongly predict avian response to novelty and cognitive challenges.
ContributorsCook, Meghan Olivia (Author) / McGraw, Kevin (Thesis director) / Bimonte-Nelson, Heather (Committee member) / Weaver, Melinda (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Rock Doves (Columba livia), also known as pigeons, are a common sight to city dwellers around the world. Often overlooked as urban pests, these birds have intriguing iridescent coloration on their necks that has been the subject of few studies. Previous studies have documented the multimodal reflectance spectra of the iridescence and the keratin cortex microstructures responsible for those properties, but do not address questions about the biological context of this coloration. In this study, I explore the factors that affect how this directional signal might appear to intended receivers (assumed to be females). Pigeon neck feathers were obtained from captive-raised birds and measured for reflectance values at numerous angles in the hemisphere above the feather to obtain a directional reflectance distribution. Each feather was mounted individually, and measurements were taken at a consistent location on the feather using a spectrophotometer; the collector was positioned directly above the feather, while we moved the light source in both azimuth and elevation on a Carden arm to simulate changes in pigeon movements during courtship. Depending on the elevation and azimuth of the light source, pigeon neck feathers shift in appearance from green to purple, with an accompanying shift in the location and intensity of reflectance peaks. Additionally, this unique coloration is due to multiple reflectance peaks in the avian vision field between 300 and 700nm. These data coupled with qualitative behavioral observations of Rock Dove courtship inform our understanding of how the color signal is displayed and how it appears to a potential mate; as a female observes the movements in a male courtship display, properties of the iridescence utilize multiple viewing angles to create a dynamic color array.
ContributorsFankhauser, Kaci Lynn (Author) / Rutowski, Ronald (Thesis director) / McGraw, Kevin (Committee member) / McBeath, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
“Tell It to the Frogs: Fukushima’s nuclear disaster and its impact on the Japanese Tree Frog” is a representation of the work from Giraudeau et. al’s “Carotenoid distribution in wild Japanese tree frogs (Hyla japonica) exposed to ionizing radiation in Fukushima.” This paper looked to see if carotenoid levels in the tree frog’s vocal sac, liver, and blood were affected by radiation from Fukushima’s power plant explosion. Without carotenoids, the pigment that gives the frogs their orange color on their necks, their courtship practices would be impacted and would not be as able to show off their fitness to potential mates. The artwork inspired by this research displayed the tree frog’s degradation over time due to radiation, starting with normal life and ending with their death and open on the table. The sculptures also pinpoint where the carotenoids were being measured with a brilliant orange glaze. Through ceramic hand building, the artist created larger than life frogs in hopes to elicit curiosity about them and their plight. While the paper did not conclude any changes in the frog’s physiology after 18 months of exposure, there are still questions that are left unanswered. Why did these frogs not have any reaction? Could there be any effects after more time has passed? Is radiation leakage as big of a problem as previously thought? The only way to get the answers to these questions is to be aware of these amphibians, the circumstances that led them to be involved, and continued research on them and radiation.
ContributorsWesterfield, Savannah (Author) / Beiner, Susan (Thesis director) / McGraw, Kevin (Committee member) / School of Life Sciences (Contributor) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Among the most ornate animal traits in nature are the angle-dependent (i.e. iridescent) structural colors of many birds, beetles, and butterflies. Though we now have a solid understanding of the mechanisms, function, and evolution of these features in several groups, less attention has been paid to the potential for angle-dependent reflectance in otherwise matte-appearing (i.e. not thought to be structurally colored) tissues. Here for the first time we describe non-iridescent angle-dependent coloration from the tail and wing feathers of several parrot species (Psittaciformes). We employed a novel approach \u2014 by calculating chromatic and achromatic contrasts (in just noticeable differences, JNDs) of straight and angled measurements of the same feather patch \u2014 to test for perceptually relevant angle-dependent changes in coloration on dorsal and ventral feather surfaces. We found, among the 15 parrot species studied, significant angle dependence for nearly all parameters (except chromatic JNDs on the ventral side of wing feathers). We then measured microstructural features on each side of feathers, including size and color of barbs and barbules, to attempt to predict interspecific variation in degree of angle-dependent reflectance. We found that hue, saturation, and brightness of feather barbs, barbule saturation, and barb:barbule coverage ratio were the strongest predictors of angle-dependent coloration. Interestingly, there was significant phylogenetic signal in only one of the seven angle-dependence models tested. These findings deepen our views on the importance of microscopic feather features in the production of directional animal coloration, especially in tissues that appear to be statically colored.
ContributorsReed, Steven Andrew (Co-author) / McGraw, Kevin (Thesis director) / Pratt, Stephen (Committee member) / Simpson, Richard (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Over the last century, society has begun to acknowledge and observe how human actions are negatively impacting the environment. Sustainable living is becoming more adopted into daily lives, including a focus on waste management and recycling. Previous informal studies have proposed that coffee grounds can be recycled and added to the soil to increase plant productivity. The objective of this experiment was to test how different concentrations of roasted coffee grounds would affect the overall plant productivity when introduced in the soil of various plant types and environmental atmospheres. Three treatments were selected (100% potting mix, 50% potting mix/50% coffee grounds, and 25% potting mix/75% coffee grounds) and applied to 3 acid-tolerating plants (radish, basil, and parsley). Each of these treatments were grown in 2 different environments, where one was planted in a Tempe, AZ backyard while the other group was planted in a lab environment, locating at Arizona State University's Tempe Campus. Each plant with its respective treatments (plant type, coffee ground treatment, and environment) had 10 identical plants for statistical accuracy, resulting in a total of 180 plants grown, observed, and analyzed for this 3-month long experiment. The plant development, plant height, length of roots, quantity of leaves, and environmental observations were recorded and used to define plant productivity in this investigation. The experiment demonstrated low survival rates in all groups including the control group, suggesting a flaw in the experimental design. Nonetheless, the experiment showed that among the surviving plants, the 75% treatment had the largest negative impact on plant productivity. The measured root lengths and leaf quantity had various results across each plant group, leaving the hypothesis unverified. Overall, the experiment was effective in demonstrating negative impacts of great concentrations of coffee grounds when introduced to various plants, but further investigation with an adjusted experimental design will need to be completed to reach a reliable conclusion.
ContributorsVan Winkle, Delaney Dare (Author) / Bang, Christofer (Thesis director) / Fox, Peter (Committee member) / Earl, Stevan (Committee member) / School of Sustainability (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Historically, studies of condition-dependent signals in animals have been male-centric, but recent work suggests that female ornaments can also communicate individual quality (e.g., disease state, fecundity). There has been a surge of interest in how urbanization alters signaling traits, but we know little about if and how cities affect signal expression in female animals. We measured carotenoid-based plumage coloration and coccidian (Isospora spp) parasite burden in desert and city populations of house finches to examine urban impacts on male and female health and attractiveness. In earlier work, we showed that male house finches are less colorful and more parasitized in the city, and we again detected that pattern in this study for males. However, though city females are also less colorful than their rural counterparts, we found that rural females were more parasitized. Also, regardless of sex and unlike rural birds, more colorful birds in the city were more heavily infected with coccidia. These results show that urban environments can disrupt signal honesty in female animals and highlight the need for more studies on how cities affect disease and condition-dependent traits in both male and female animals.
ContributorsSykes, Brooke Emma (Author) / McGraw, Kevin (Thesis director) / Sweazea, Karen (Committee member) / Hutton, Pierce (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
There are two electrophysiological states of sleep in birds (rapid-eye-movement sleep [REM] and slow-wave sleep [SWS]), which have different functions and costs. REM improves memory consolidation, while SWS is neuro-restorative but also exposes the animal to more risk during this deep-sleep phase. Birds who sleep in more exposed microsites are known to invest proportionally less in SWS (presumably to ensure proper vigilance), but otherwise little else is known about the ecological or behavioral predictors of how much time birds devote to REM v. SWS sleep. In this comparative analysis, we examine how proportional time spent in SWS v. REM is related to brain mass and duration of the incubation period in adults. Brain mass and incubation period were chosen as predictors of sleep state investment because brain mass is positively correlated with body size (and may show a relationship between physical development and sleep) and incubation period can be a link used to show similarities and differences between birds and mammals (using mammalian gestation period). We hypothesized that (1) species with larger brains (relative to body size and also while controlling for phylogeny) would have higher demands for information processing, and possibly proportionally outweigh neuro-repair, and thus devote more time to REM and that (2) species with longer incubation periods would have proportionally more REM due to the extended time required for overnight predator vigilance (and not falling into deep sleep) while on the nest. We found, using neurophysiological data from literature on 27 bird species, that adults from species with longer incubation periods spent proportionally more time in REM sleep, but that relative brain size was not significantly associated with relative time spent in REM or SWS. We therefore provide evidence that mammalian and avian REM in response to incubation/gestation period have convergently evolved. Our results suggest that overnight environmental conditions (e.g. sleep site exposure) might have a greater effect on sleep parameters than gross morphological attributes.
ContributorsRaiffe, Joshua Sapell (Author) / McGraw, Kevin (Thesis director) / Deviche, Pierre (Committee member) / Hutton, Pierce (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Humans have greatly altered the night-time photic environment via the production of artificial light at night (ALAN; e.g. street lights, car traffic, billboards, lit buildings). ALAN is problematic because it may significantly alter the seasonal/daily physiological rhythms or behaviors of animals. There has been considerable interest in the impacts of ALAN on health in humans and lab animals, but most such work has centered on adults and we know comparatively little about effects on young animals. We exposed 3-week-old king quail (Excalfactoria chinensis) to a constant overnight blue-light regime for 6 weeks and assessed weekly bactericidal activity of plasma against Escherichia coli - a commonly employed metric of innate immunity in animals. We found that chronic ALAN exposure significantly increased immune function, and that this elevation in immune performance manifested at different developmental time points in males and females. These results counter the pervasive notion that overnight light exposure is universally physiologically harmful to diurnal organisms and indicate that ALAN can provide sex-specific, short-term immunological boosts to developing animals.
ContributorsSaini, Chandan (Author) / McGraw, Kevin (Thesis director) / Hutton, Pierce (Committee member) / Sweazea, Karen (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Obesity and related health disparities including type 2 diabetes disproportionately impact Latino youth. These health disparities may be the result of gene-environment interactions, but limited research has examined these interactions in the pediatric age group. Lifestyle intervention is the cornerstone for preventing diabetes among high-risk populations and epigenetic and genetic factors may help explain the biological mechanisms underlying diabetes risk reduction following lifestyle changes. MicroRNAs (miRNAs) are small, non-coding RNA’s that regulate gene expression and have emerged as potential biomarkers for predicting type 2 diabetes risk in adults but have yet to be applied to youth. Therefore, the purpose of this study was to identify changes in miRNA expression among Latino youth with prediabetes (4 female/2 male, ages 14-16, BMI percentile 99 ±.2) who participated in a 12-week lifestyle intervention focused on increasing physical activity and improving nutrition-related behaviors.
ContributorsKarch, Jamie (Co-author) / Day, Samantha (Co-author) / Shaibi, Gabriel (Thesis director) / Coletta, Dawn (Committee member) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Reproduction is energetically costly and seasonal breeding has evolved to capitalize on predictable increases in food availability. The synchronization of breeding with periods of peak food availability is especially important for small birds, most of which do not store an extensive amount of energy. The annual change in photoperiod is the primary environmental cue regulating reproductive development, but must be integrated with supplementary cues relating to local energetic conditions. Photoperiodic regulation of the reproductive neuroendocrine system is well described in seasonally breeding birds, but the mechanisms that these animals use to integrate supplementary cues remain unclear. I hypothesized that (a) environmental cues that negatively affect energy balance inhibit reproductive development by acting at multiple levels along the reproductive endocrine axis including the hypothalamus (b) that the availability of metabolic fuels conveys alterations in energy balance to the reproductive system. I investigated these hypotheses in male house finches, Haemorhous mexicanus, caught in the wild and brought into captivity. I first experimentally reduced body condition through food restriction and found that gonadal development and function are inhibited and these changes are associated with changes in hypothalamic gonadotropin-releasing hormone (GnRH). I then investigated this neuroendocrine integration and found that finches maintain reproductive flexibility through modifying the release of accumulated GnRH stores in response to energetic conditions. Lastly, I investigated the role of metabolic fuels in coordinating reproductive responses under two different models of negative energy balance, decreased energy intake (food restriction) and increased energy expenditure (high temperatures). Exposure to high temperatures lowered body condition and reduced food intake. Reproductive development was inhibited under both energy challenges, and occurred with decreased gonadal gene expression of enzymes involved in steroid synthesis. Minor changes in fuel utilization occurred under food restriction but not high temperatures. My results support the hypothesis that negative energy balance inhibits reproductive development through multilevel effects on the hypothalamus and gonads. These studies are among the first to demonstrate a negative effect of high temperatures on reproductive development in a wild bird. Overall, the above findings provide important foundations for investigations into adaptive responses of breeding in energetically variable environments.
ContributorsValle, Shelley (Author) / Deviche, Pierre (Thesis advisor) / McGraw, Kevin (Committee member) / Orchinik, Miles (Committee member) / Propper, Catherine (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2018