Spelling suggestions: "subject:"animals’behavior"" "subject:"animals:behavior""
31 |
Integrating Multiple Technologies to Understand the Foraging Behavior and Habitat Use of Monk Seals in the Main Hawaiian IslandsWilson, Kenady Colleen January 2015 (has links)
<p>Hawaiian monk seal abundance is currently declining by about 4% per year with current population estimates around 1,100 individuals. Although the overall population continues to decline, a small sub-population in the main Hawaiian Islands (MHI) appears to be increasing by roughly 6% per year. Monk seal conservation and recovery efforts in the MHI have been hindered by the perception that seals do not belong there, and that they compete with fisheries and damage coral reefs. Education and outreach efforts describing the actual impact of monk seals in the MHI are currently underway, but we actually know very little about their at-sea behavior, especially in the MHI, even though Hawaiian monk seals have been studied extensively since the 1980s. The central objective of my dissertation was to describe monk seal behavior and develop a baseline for monk seal foraging ecology and habitat use in the MHI. To accomplish this I combined three-axis accelerometers, National Geographic Crittercams, and GPS tags to study monk seal foraging behavior. I instrumented 16 seals between 2010 and 2014 on the islands of Molokai, Kauai, and Oahu and deployed an additional 24 GPS tags without the accelerometer and Crittercam. I recovered each Crittercam/accelerometer package 3-6 days after deployment, resulting in an average of 6.14 hours of video footage per seal. The GPS tags continued to record data for 3-6 months providing long-term summaries of dive and haul-out behavior. Using a Bayesian framework I modeled monk seal behavior and habitat use, and developed a method to identify feeding events from accelerometer data. There was a high level of individual variation in the movements of monk seals, but general descriptions of their behavior were accurate at the population level. On average, foraging trips lasted 0.81 ± 1.38 days and seals traveled 28.45 ± 82.03 km per trip. Most seals began benthic dives shortly after entering the water, with most dives occurring between 20-40 m. I used kernel density estimation to define the 50% (core area) and 95% (home range) utilization distribution for each seal. The median home range and core area size for seals in the MHI was 265.62 km2 and 1,564.56 km2, respectively. The pitch axis of the accelerometer was a reliable metric, with over 70% accuracy, for identifying foraging events for monk seals. Body motion over the course of a dive, and how close the seal was to the seafloor during a dive (dive ratio) were the best predictors of these foraging events. Consequently, dive ratio was used to infer foraging in long-term telemetry records that lacked concurrent accelerometer data. Analysis of these data relative to habitat preferences revealed two distinct movement modes for monk seals in the MHI: near shore and offshore/inter-island. My research developed the first thorough understanding of monk seal movements and habitat use in the MHI and provided insight into the mechanisms contributing to the behavioral variability observed for this species. I hope that a detailed understanding of the foraging behavior of monk seals will provide insight into their true role in the ecosystem and help foster the recovery of this critically endangered species.</p> / Dissertation
|
32 |
Aspects of temperature adaptation in PeromyscusHayward, John Stanley January 1964 (has links)
Six races of Peromyscus, from a variety of habitats, have been studied with respect to factors involved in adaptation to environmental temperature. The central theme of the study was to assess the extent to which metabolic rate is involved in the processes of distribution and speciation in this genus.
A unique, electrolytic respirometer for the accurate measurement of oxygen consumption was constructed and reported in the literature. With this apparatus, the metabolic rate characteristics of the six races were measured over the temperature range 0° to 35°C. After acclimation to standardized laboratory conditions, critical temperatures and metabolic responses to temperatures below thermoneutrality were primarily related to body size. They show, therefore, no evidence of racial metabolic rate adaptation or significant insulative differences. Body weight per se is not correlated with the climate of the respective habitats. A single equation which predicts the metabolic rate of these races at any temperature between 0° and 27°C, from a knowledge of body weight and body temperature, is derived.
When considered as a single group, the basal oxygen consumption of all races varied with body weight 0.69 and was insignificantly different from the accepted interspeciesapproximation. The basal metabolic rates of each race showed no temperature-adaptive differences, especially when considered in relation to body composition. The body composition in terms of water, fat and protein was determined for all individuals. The importance of considering body composition, especially fatness, in comparative studies of metabolic rate is emphasized. It is concluded that metabolic rate is inadaptive to climate in these races of Peromyscus and consequently has played no important role in their distribution and speciation.
It is shown that the major temperature-adaptive feature of these small mammals is the use of a suitable microclimate. Measurements of the ambient temperatures prevailing in the microhabitats of the six races during winter and summer are presented. These data indicate that there is no significant differential selective pressure for temperature adaptation among the six races, and are complementary to the finding that metabolic rate is inadaptive to gross climate in Peromyscus. / Science, Faculty of / Zoology, Department of / Graduate
|
33 |
The effects of infantile handling and sensory deprivation on adult avoidance learning in the ratMarvin, Jeffrey January 1970 (has links)
Two groups of rats, handled on days (1-11) and days (21-32), and a nonhandled group were tested at 75 days of age on a modified two-way shuttle avoidance task. One-half of the animals were light-reared, the other half dark-reared. Measures taken included percentage correct avoidance responses (AR), intertrial interval responses (ITIR), escape response and avoidance response latencies (ERL and ARL), and A-Scores in percentage form (AR - ITIR). No differences in any of these measures except ERL was observed as a result of handling, though rearing in differential environments provided significant differences in AR, A-Scores, and ERL. Results were interpreted in terms of several relevant theories, with Melzack's (1968) hypothesis proving the most parsimonious in accounting for the data. / Arts, Faculty of / Psychology, Department of / Graduate
|
34 |
The effects of social experience on play and agonistic behavior in the golden hamster and the Mongolian gerbilSkirrow, Margaret Helen Wort January 1965 (has links)
To determine the effects of different social conditions on play and agonistic behaviour, 25-day old golden hamsters and Mongolian gerbils were divided into four groups which differed with respect to social experience after weaning. Every day, from 26 to 61 days of age, the young hamsters were observed for numbers and durations of fight-type interactions in a 15-minute period. Every third or sixth day from 27 to 60 days of age, the gerbils were similarly tested.
Seven to 14 percent of play fights between hamsters involved more than two animals simultaneously. Communally reared hamsters mixed with strangers played with strangers 71 percent of the time, while 90 percent of real fights involved strangers. Neither of these measures involved the effects of early social experience.
Isolation causes earlier cessation of play and earlier onset of real fights in golden hamsters. Isolation also leads to a significant increase in the amount of play and real fighting in these animals.
Gerbils raised in isolation with a toy show significantly more play than do gerbils reared under different social conditions. Gerbils reared communally with the mother fight significantly more with strangers than they do with familar animals, and fight significantly more than do animals reared communally with siblings, or in isolation with or without a ping pong ball. / Science, Faculty of / Zoology, Department of / Graduate
|
35 |
The Influence of Demography, Development and Death on Seasonal Labor Allocation in the Florida Harvester Ant (Pogonomyrmex Badius)Unknown Date (has links)
Eusocial insect societies are analogous to organisms in that the demography, development and regulation of workers within are shaped by selection acting on whole colony
characteristics. Just as relative investment varies across the lifetime and reproductive cycle of a traditional organism, adaptive patterns of worker allocation are expected to vary with
colony development and need across each annual cycle. Despite these predictions, adaptive patterns of labor allocation remain un-described for most social insect societies. This dissertation
identifies a seasonal pattern of forager allocation in colonies of the Florida harvester ant (Pogonomyrmex badius) and describes its relationship to colony demography, size, reproduction,
worker development rate, death rate, longevity, and neighborhood dynamics. Aging P. badius workers progress through a sequence of interior labor roles before leaving the nest to forage. By
marking and recapturing foragers, forager population size was estimated and foragers were identified as a discrete, age-correlated labor group that resides only in the top 12cm of nests that
may be more than 200cm deep. Excavation and census of whole colonies revealed that foragers were present in a consistent ratio to the colony's larval population from May through August, but
that forager allocation was not a response to larval presence. Proportional allocation to foraging followed an annual pattern, shaped by the interaction of seasonal phases of colony growth
and worker development rate. Forager allocation began in March or April and increased to a peak of approximately 40% of the colony in June, as colonies provisioned alates for mating flights
in the days surrounding the summer solstice. In spring, proportion foraging increased due to an increase in forager number combined with a reduction in colony size. Beginning in late summer,
proportional allocation to foraging decreased, as colonies grew through new worker birth and forager replacement declined. This annual pattern was shaped by a five-fold difference in the age
of summer and autumn-born workers when they entered the forager population (43 vs. 200+ days). The chronological age of foragers was revealed by collecting whole colonies across two annual
cycles, marking age cohorts with colored wire-belts, releasing each colony into a field nest created from melting buried ice chambers, then monitoring the forager population for the
appearance of each marked cohort. Slow-developing workers, produced from late August until mid-October each year, dominated the forager population the following March through mid-July; while
fast developing workers appeared in early June and developed rapidly to become foragers the following month, overlapping with their older sisters. While wild foragers of both types lived an
average maximum of 27 days after entering the forager population, these same foragers were capable of surviving for hundreds of days in the laboratory. Likewise, restricting the foraging
range of wild foragers increased forager longevity by 57%, demonstrating that foraging carries mortality risks and the observed age at death was not part of a developmental program involving
senescence in P. badius. By removing neighboring colonies, this study also showed that interactions with conspecific neighbors can influence the labor thresholds of individual workers, and
the demographic structure of whole colonies, as neighbors account for 30% of forager mortality in the spring. At the colony level, increased forager longevity suppressed the movement of new
workers into the forager population, increasing their time in earlier labor roles and promoting colony growth. In contrast, both removing 50% of the forager population and doubling the larval
population did not induce forager replacement or increase the daily rate of new foragers added within seven days. Together, these results suggest a unidirectional control of labor allocation
in P. badius, where the forager population size is not maintained by workers detecting colony need and filling vacancies, but by workers developing at a rate selected to allow forager
replacement. In essence, the annual cycle of forager allocation emerges as P. badius workers 'age' into behavioral roles at environmentally appropriate times, in the same proportions, on
nearly the same dates each year and experience a predictable death rate. This process allows colonies to divide a limited number of workers between competing functions without a leader.The
findings of this study reinforce our understanding of the organism-like nature of social insect colonies. Like cells in a body, the thousands of individual insects in a P. badius colony are
organized into functional labor groups, which are responsive to cycles of growth, reproduction and dormancy through self-regulating processes. The emergence of measurable, colony-level traits
from the accumulation of thousands of transient individuals, from multiple generations is one of the most striking feats of social organization across taxa. / A Dissertation submitted to the Department of Biological Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2014. / October 2, 2014. / ant colony behavior, division of labor, Florida harvester ant, Pogonomyrmex badius, labor allocation, social inhibition, superorganism / Includes bibliographical references. / Walter R. Tschinkel, Professor Directing Dissertation; Emily H. DuVal, Committee Member; Lisa C. Lyons, Committee Member; Jeanette L. Wulff, Committee
Member.
|
36 |
Experimental Investigations in Public EconomicsUnknown Date (has links)
There has been an explosion in the use of experimental methods since the 1980s. This dissertation applies those experimental methods to various topics in public economics like tax evasion, crowding-out, labor supply, and cooperation. In chapter one I manipulate tax rates and whether students are capable of tax evasion in the laboratory. In joint provision settings, where public goods are provided through donations and tax revenues, these manipulations provide clean inference about the effects of tax evasion on crowding-out. Moreover, I collect measures of warm glow to estimate its relationship with contribution behavior across evasion settings. I find the usual crowding-out result when there is no tax evasion, however, I find complete crowding-out when tax evasion is possible. The collected measures of warm glow do not explain these results. The second chapter is co-authored with Robert White. In that chapter students complete real effort tasks in the laboratory for a piece-rate payment and we manipulate the shapes of these piece-rate earnings schedules. These shapes are intended to capture different features of the U.S. tax code when the loss of benefits (e.g. SNAP, WIC, Section 8 Housing, and Medicaid) are accounted for. We analyze how the shapes of these piece-rate schedules (as well as other behavioral factors (e.g. loss aversion, overconfidence, etc.) affect labor supply. We find that the piece-rate schedules that imitate ``notches" (or discontinuous jumps in the budget set) do reduce labor supply, however, this behavioral response to taxation is learned across rounds. Chapter three provides the first direct study of the ``restart effect" in public goods games. The restart effect is said to occur when there is an upward pulse in contributions to the public good following a stoppage in game play. I manipulate the language of the experimental instructions as well as the length of time prior to the stoppage in game play to search for facts about what supports the restart effect. I find that language in the instructions about when the stoppages occur promotes the restart effect. Finally, Chapter four presents evidence from a non-experimental project where data problems prevented useful findings about the relationship between competition and public service quality. / A Dissertation submitted to the Department of Economics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2016. / April 21, 2016. / crowding-out, laboratory experiments, labor supply, notches, public goods, taxation / Includes bibliographical references. / Mark Isaac, Professor Directing Dissertation; Charles Barrilleaux, University Representative; David Cooper, Committee Member; Thomas Zuehlke, Committee Member.
|
37 |
Game-Theoretic Models of Animal Behavior Observed in Some Recent ExperimentsUnknown Date (has links)
In this dissertation, we create three theoretical models to answer questions raised by recent experiments that lie beyond the scope of current theory. In the landmark-effect model, we determine size, shape and location for a territory that is optimal in the sense of minimizing defense costs, when a given proportion of the boundary is landmarked and its primary benefit in terms of fitness is greater ease of detecting intruders across it. In the subjective-resource-value model, we develop a game-theoretic model based on the War-of-Attrition game. Our results confirm that allowing players to adapt their subjective resource value based on their experiences can generate strong winner effects with weak or even no loser effects, which is not predicted by other theoretical models. In the rearguard-action model, we develop two versions of a game-theoretic model with different hypotheses on the function of volatile chemical emissions in animal contests, and we compare their results with observations in experiments. The two hypotheses are whether volatile chemicals are released to prevent the winner of the current round of contest from translating its victory into permanent possession of a contested resource, or are used to prevent a winner from inflicting costs on a fleeing loser. / A Dissertation submitted to the Department of Mathematics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2017. / April 10, 2017. / Behaviors, Contest, Game theory, Landmark effect, Subjective resource value, Volatile chemical / Includes bibliographical references. / Mike Mesterton-Gibbons, Professor Directing Dissertation; Fred W. Huffer, University Representative; Monica Hurdal, Committee Member; Alec N. Kercheval, Committee Member; Jack Quine, Committee Member.
|
38 |
The Effects of Child Maltreatment on the Likelihood of Committing Violence in at-Risk Youth: A Family Systems, Trauma Theory, and Need to Belong FrameworkUnknown Date (has links)
One of the most concerning effects of child maltreatment that has been of interest to researchers and practitioners over the past few decades is the documented increased risk of victimized children engaging in violence during childhood and adulthood. Despite the intergenerational transmission of violence being empirically documented in numerous studies, the influence of maltreatment typology on this continuity of violence is still in the early stages of research. Hence, limited information exists as to which types of maltreatment are the most likely to lead to violence and what factors moderate the relationship between childhood victimization and an increased risk of violence and aggressive behavior, that can be modified in treatment programs. Concepts from family systems, trauma, and need to belong theories are integrated to provide a framework explaining why the type of maltreatment and a lack of family belonging may predict the likelihood to engage in violence during childhood. Using a sample of juveniles leaving the Florida department of juvenile justice community supervision program between the years of 2010 and 2011 (n= 6,537), this study examines the effect of four different types of maltreatment on the likelihood of commission of violent behavior. Findings reveal that maltreated children are less likely to have family belonging than non-maltreated children and are more likely to have committed a violent offense. Specifically, children who have experienced sexual abuse in childhood are at the greatest risk for being court ordered to community supervision for a violent offense, followed by children who have experienced multiple types of maltreatment. While children with family belonging are less likely to commit violence, the results do not suggest that family belonging moderates the relationship between maltreatment and the propensity to commit violence. / A Dissertation submitted to the College of Criminology and Criminal Justice in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2018. / July 18, 2018. / at-risk, child maltreatment, family belonging, intergenerational transmission of violence, trauma / Includes bibliographical references. / William Bales, Professor Directing Dissertation; Lenore McWey, University Representative; Eric Stewart, Committee Member; Jillian Turanovic, Committee Member.
|
39 |
The role of prenatal auditory stimulation in the development of filial behaviour in the domestic ducklingDe Wet, John Manning January 1974 (has links)
The aim of the first three experiments was to delineate the physical characteristics of an artificial call for which naive Peking X Aylesbury ducklings show the greatest natural preference. In each experiment SO ducklings were tested at 20 ± 2 hrs. posthatching, for following and approach responses to one of four auditory stimulus conditions or a silent model. The responsiveness of subjects was greatest when the call contained tone frequencies of 500, 800, and 1600Hz and was presented at a repetition rate of 4/second with a note duration of 50 milliseconds (Optimal call). In Experiment 4 Peking X Aylesbury eggs were exposed to intermittent prenatal stimulation with the optimal call and the hatchlings were tested for responsiveness to this call at 20 ± 2 hrs. posthatching. Subjects with prenatal auditory experience of the optimal call showed significantly greater responsiveness to this call than non-stimulated control subjects. The aim of the final experiment was to determine whether the natural auditory stimulus preferences of ducklings could be overridden through sheer prenatal experience of a non-preferred call. Ducklings with prenatal experience of the non-preferred call continued to show as strong a preference for the optimal call as non stimulated control subjects. The responses of both stimulated and non-stimulated subjects to the optimal call were significantly stronger than the responses of stimulated and non-stimulated subjects to the non-preferred call. The responses of stimulated subjects to the non-preferred call were only slightly stronger than responses of non-stimulated subjects to the same call. These results indicate that responsiveness to calls for which naive birds show the greatest preference is enhanced by prenatal experience of the preferred call. This effect is not evident, however, when subjects are stimulated prenatally with a non-preferred call.
|
40 |
The motivation for hoarding behaviour in hooded rats.Daly, Martin, 1944- January 1968 (has links)
No description available.
|
Page generated in 0.0548 seconds