Matching Items (413)
ContributorsWard, Geoffrey Harris (Performer) / ASU Library. Music Library (Publisher)
Created2018-03-18
Description
ABSTRACT 1. Aposematic signals advertise prey distastefulness or metabolic unprofitability to potential predators and have evolved independently in many prey groups over the course of evolutionary history as a means of protection from predation. Most aposematic signals investigated to date exhibit highly chromatic patterning; however, relatives in these toxic groups with patterns of very low chroma have been largely overlooked. 2. We propose that bright displays with low chroma arose in toxic prey species because they were more effective at deterring predation than were their chromatic counterparts, especially when viewed in relatively low light environments such as forest understories. 3. We analyzed the reflectance and radiance of color patches on the wings of 90 tropical butterfly species that belong to groups with documented toxicity that vary in their habitat preferences to test this prediction: Warning signal chroma and perceived chromaticity are expected to be higher and brightness lower in species that fly in open environments when compared to those that fly in forested environments. 4. Analyses of the reflectance and radiance of warning color patches and predator visual modeling support this prediction. Moreover, phylogenetic tests, which correct for statistical non-independence due to phylogenetic relatedness of test species, also support the hypothesis of an evolutionary correlation between perceived chromaticity of aposematic signals and the flight habits of the butterflies that exhibit these signals.
ContributorsDouglas, Jonathan Marion (Author) / Rutowski, Ronald L (Thesis advisor) / Gadau, Juergen (Committee member) / McGraw, Kevin J. (Committee member) / Arizona State University (Publisher)
Created2013
Description
As an evolutionary force, hybridization outcomes include introgression, admixture, speciation, and reproductive isolation. While hybridization has been studied in several primates, the marmoset genus Callithrix is an important, but little studied example of Neotropical hybridization. Varying degrees of reproductive isolation exist between Callithrix species, and hybridization occurs at species borders or regions containing introduced and native species. Interbreeding between Callithrix species carries important implications for biodiversity and genetic integrity within the genus. However, species origins and levels of genetic admixture in marmoset hybrid zones are generally unknown, and few population genetic studies of individual Callithrix species exist. Using the mitochondrial control region and 44 microsatellite markers, this work explored the genetic diversity and species origins of two C. penicillata and C. jacchus hybrid zones, as well as genetic diversity and divergence in the parental species. Both marker types showed that C. penicillata is more genetically diverse than C. jacchus. Based on mtDNA, C. jacchus seems to have experienced a past population expansion and C. penicillata evolved under constant population size. The data revealed the existence of a previously undocumented natural hybrid zone along the São Francisco River in NE Brazil and confirmed species origins of an anthropogenic zone in Rio de Janeiro state. The data also showed much lower levels of admixture and genetic diversity within the natural hybrid zone than in the anthropogenic zone. Further, the data suggested that the São Francisco River is an important geographic barrier to gene flow in the natural hybrid zone. On the other hand, admixture patterns within the anthropogenic hybrid zone suggested collapse of reproductive barriers, and the formation of a hybrid marmoset swarm. Thus, this work suggested different evolutionary dynamics in anthropogenic vs. natural animal hybrid zones. Restriction Associated DNA sequencing (RADseq) identified a large number of single nucleotide polymorphisms within C. jacchus and C. penicillata genomes. These preliminary data were used to measure intraspecific genomic diversity and interspecific divergence. In the future, RADseq will be used to study genus-wide diversity of Callithrix species, examine past and present marmoset demographic history, and applied to the evolutionary study of marmoset hybridization.
ContributorsMalukiewicz, Joanna (Author) / Stone, Anne C. (Thesis advisor) / Nash, Leanne (Committee member) / Rosenberg, Michael (Committee member) / Hedrick, Phil (Committee member) / Ruiz-Miranda, Carlo (Committee member) / Arizona State University (Publisher)
Created2013
Description
Identifying the ecological role, or niche, that a species occupies within their larger community elucidates environmental adaptability and evolutionary success. This dissertation investigates the occupied niche of chimpanzees (Pan troglodytes schweinfurthii) living in an open, dry savanna-woodland environment by examining patterns of resource use and interspecific interactions. Data were collected October 2010--November 2011 at Issa, in the Ugalla region of western Tanzania, which is one of the driest, most open, and seasonal habitats inhabited by chimpanzees. Unlike most primatological studies which employ methods that include focal follows, this study focused instead on observing 'resource patches' for chimpanzees. Patch focals allow for the observation of all animals within a study area; capture resources that are not used by the study species; and are particularly well suited for unhabituated communities. In order to better understand relationships between environment and behavior, data collected at Issa are compared with published data from other chimpanzee populations. Issa chimpanzees were expected to have broader resource use than forest chimpanzees, as well as increased competition with other fauna, due to fewer available resources. However, in contrast to the assumption of food scarcity in dry habitats, dietary resources were available throughout the year. Like other populations, the diet of Issa chimpanzees consisted of mostly fruit, but unlike at other sites, the majority of plants consumed were woodland species. Additionally, although chimpanzees and other fauna shared spatial and dietary resources, there was only nominal overlap. These results point to extremely low levels of indirect competition between chimpanzees and other fauna. Despite extensive study of forest chimpanzees, little is known about their role within their faunal community in open, dry habitats, nor about how greater seasonality affects resource use. This project addresses both of these important issues and fosters novel approaches in anthropological studies, especially in reference to chimpanzee ecology and evolution. Understanding current chimpanzee behavioral relationships with their environments shapes hypotheses about their pasts, and also informs predictions about behaviors of similar taxa in paleo-environments. Lastly, examining the ecological role of chimpanzees within their larger communities will influence the formation of, as well as evaluate, conservation strategies.
ContributorsRussak, Samantha M (Author) / Reed, Kaye E (Thesis advisor) / Nash, Leanne T. (Committee member) / Schwartz, Gary T (Committee member) / Arizona State University (Publisher)
Created2013
Description
Parental care provides many benefits to offspring. One widely realized benefit is enhanced regulation of offspring's thermal environment. The developmental thermal environment during development can be optimized behaviorally through nest site selection and brooding, and it can be further enhanced by physiological heat production. In fact, enhancement of the developmental thermal environment has been proposed as the initial driving force for the evolution of endothermy in bird and mammals. I used pythons (Squamata: Pythonidae) to expand existing knowledge of behavioral and physiological parental tactics used to regulate offspring thermal environment. I first demonstrated that brooding behavior in the Children's python (Antaresia childreni) is largely driven by internal mechanisms, similar to solitary birds, suggesting that the early evolution of the parent-offspring association was probably hormonally driven. Two species of python are known to be facultatively thermogenic (i.e., are endothermic during reproduction). I expand current knowledge of thermogenesis in Burmese pythons (Python molurus) by demonstrating that females use their own body temperature to modulate thermogenesis. Although pythons are commonly cited as thermogenic, the actual extent of thermogenesis within the family Pythonidae is unknown. Thus, I assessed the thermogenic capability of five previously unstudied species of python to aid in understanding phylogenetic, morphological, and distributional influences on thermogenesis in pythons. Results suggest that facultative thermogenesis is likely rare among pythons. To understand why it is rare, I used an artificial model to demonstrate that energetic costs to the female likely outweigh thermal benefits to the clutch in species that do not inhabit cooler latitudes or lack large energy reserves. In combination with other studies, these results show that facultative thermogenesis during brooding in pythons likely requires particular ecological and physiological factors for its evolution.
ContributorsBrashears, Jake (Author) / DeNardo, Dale (Thesis advisor) / Harrison, Jon (Committee member) / Deviche, Pierre (Committee member) / McGraw, Kevin (Committee member) / Smith, Andrew (Committee member) / Arizona State University (Publisher)
Created2012
Description
Social structure affects many aspects of ecology including mating systems, dispersal, and movements. The quality and pattern of associations among individuals can define social structure, thus detailed behavioral observations are vital to understanding species social structure and many other aspects of their ecology. In squamate reptiles (lizards and snakes), detailed observations of associations among individuals have been primarily limited to several lineages of lizards and have revealed a variety of social structures, including polygynous family group-living and monogamous pair-living. Here I describe the social structure of two communities within a population of Arizona black rattlesnakes (Crotalus cerberus) using association indices and social network analysis. I used remote timelapse cameras to semi-continuously sample rattlesnake behavior at communal basking sites during early April through mid-May in 2011 and 2012. I calculated an association index for each dyad (proportion of time they spent together) and used these indices to construct a weighted, undirected social network for each community. I found that individual C. cerberus vary in their tendency to form associations and are selective about with whom they associate. Some individuals preferred to be alone or in small groups while others preferred to be in large groups. Overall, rattlesnakes exhibited non-random association patterns, and this result was mainly driven by association selection of adults. Adults had greater association strengths and were more likely to have limited and selected associates. I identified eight subgroups within the two communities (five in one, three in the other), all of which contained adults and juveniles. My study is the first to show selected associations among individual snakes, but to my knowledge it is also the first to use association indices and social network analysis to examine association patterns among snakes. When these methods are applied to other snake species that aggregate, I anticipate the `discovery' of similar social structures.
ContributorsAmarello, Melissa (Author) / DeNardo, Dale F (Thesis advisor) / Sullivan, Brian K. (Committee member) / Schuett, Gordon W. (Committee member) / Arizona State University (Publisher)
Created2012
Description
Sexual and social signals have long been thought to play an important role in speciation and diversity; hence, investigations of intraspecific communication may lead to important insights regarding key processes of evolution. Though we have learned much about the control, function, and evolution of animal communication by studying several very common signal types, investigating rare classes of signals may provide new information about how and why animals communicate. My dissertation research focused on rapid physiological color change, a rare signal-type used by relatively few taxa. To answer longstanding questions about this rare class of signals, I employed novel methods to measure rapid color change signals of male veiled chameleons Chamaeleo calyptratus in real-time as seen by the intended conspecific receivers, as well as the associated behaviors of signalers and receivers. In the context of agonistic male-male interactions, I found that the brightness achieved by individual males and the speed of color change were the best predictors of aggression and fighting ability. Conversely, I found that rapid skin darkening serves as a signal of submission for male chameleons, reducing aggression from winners when displayed by losers. Additionally, my research revealed that the timing of maximum skin brightness and speed of brightening were the best predictors of maximum bite force and circulating testosterone levels, respectively. Together, these results indicated that different aspects of color change can communicate information about contest strategy, physiology, and performance ability. Lastly, when I experimentally manipulated the external appearance of chameleons, I found that "dishonestly" signaling individuals (i.e. those whose behavior did not match their manipulated color) received higher aggression from unpainted opponents. The increased aggression received by dishonest signalers suggests that social costs play an important role in maintaining the honesty of rapid color change signals in veiled chameleons. Though the color change abilities of chameleons have interested humans since the time of Aristotle, little was previously known about the signal content of such changes. Documenting the behavioral contexts and information content of these signals has provided an important first step in understanding the current function, underlying control mechanisms, and evolutionary origins of this rare signal type.
ContributorsLigon, Russell (Author) / McGraw, Kevin J. (Committee member) / DeNardo, Dale F (Committee member) / Karsten, Kristopher B (Committee member) / Rutowski, Ronald L (Committee member) / Deviche, Pierre (Committee member) / Arizona State University (Publisher)
Created2015
ContributorsBolari, John (Performer) / ASU Library. Music Library (Publisher)
Created2018-10-04
ContributorsOftedahl, Paul (Performer) / ASU Library. Music Library (Publisher)
Created2018-09-29
Description
The truth about animal husbandry is not being explained properly to those who visit zoos, or, more importantly, to those who vehemently oppose zoos and animal captivity. Currently, the quality of modern zoos is communicated from within the zoo, where most animal rights activists would never step foot. I have researched the current influence of animal welfare on the practice of behavioral husbandry in modern institutions. In order to bring benefits of behavioral research to the debate on animal welfare, I have also observed two tigers at the Out of Africa Wildlife Park in Camp Verde, Arizona. The reality is that modern zoos are dedicated to improving the quality of life in captivity for rescued animals and to providing education and genetic diversity for their species. Accreditation standards are constantly evolving with discovery and criticism from professionals in the field of animal husbandry and behavior. Even tigers at the Out of Africa Wildlife Park display minimal stereotypic behaviors compared to other studies of captive tigers, and both of these cats also participate in healthy play and environmental enrichment use. Current advancements in animal welfare, enrichment, and animal husbandry project an excellent outlook for the zoological facilities of the future.
ContributorsSamuelson, Maisy Louise (Author) / Meloy, Elizabeth (Thesis director) / Caron, Martha (Committee member) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12