In this study, I describe the seasonality of reproduction in bottlenose dolphins by examining data from stranded animals, photographic surveys and focal follows. I examined inter-birth intervals from focal follows of known female dolphins. I found bottlenose dolphins that frequent the coastal waters of North Carolina to be comprised of at least two populations; one with a primarily spring birthing peak and a presumed second (or second and third) with two smaller birthing peaks in the fall and winter. These animals are reproducing at 2-3 year inter-birth intervals, which are shorter than bottlenose dolphin inter-birth intervals in the Moray Firth, Scotland, Shark Bay, Australia, or Sarasota Bay, FL. A decrease in reproductive intervals can indicate a density-dependent response to an anthropogenic disturbance or a natural change. Association patterns between and among these known females revealed relationships that have persisted for more than a decade. Most association patterns of the female dolphins in this area are long-term casual acquaintances which are evident in the fission-fusion grouping pattern, and individuals are not highly gregarious. Females appear to associate with most other females in the local area and do not form bands, as defined by researchers in Sarasota, FL (Wells et al. 1987). However, females do exhibit preferred associates, with whom they associate, regardless of reproductive state. Associations of females with young of the year were slightly stronger than associations between females with different aged calves, except for preferred associates. Future work will include genetic research on some of these known females, and continued study of the life and reproductive histories of these known females and their offspring. / Dissertation

<p>The pace of life history is highly variable across mammals, and several evolutionary biologists have theorized that the tempo of a species' life history is set by external factors. These factors, such as food availability and predation pressure, determine mortality rates. In turn, mortality rate determines the age at maturity. High mortality rate results in early age at maturity; individuals must grow and reproduce quickly because of the high risk of death. Conversely, a low mortality rate is allows individuals to prolong their growth period and reproduce slowly. This theory assumes that growth rates are constant across species, and thus body size is determined by mortality rates.</p><p>This project posits that the intrinsic characteristics of species set the pace of life history. Among anthropoids, there is a great deal of variation in growth rates and the pace of life history relative to body size. The hypotheses proposed by this project state that the degree of encephalization in a species determines the growth rates, the length of the growth period, and the adult lifespan. Growing a large brain is costly and requires a prolonged period of development. However, a large brain has the benefit of reducing mortality by facilitating cognitive strategies for food procurement and predator avoidance. This cost/benefit balance results in the pattern of life-history variation in which mortality rates are correlated with the length of the growth period. However, the causal arrows are reversed; instead of the mortality rate determining the age at maturity and consequently the size of the species, the relative brain size of the anthropoid determines the mortality rate and the age maturity.</p><p>These hypotheses were tested by determining the body and brain growth trajectories of thirteen anthropoids, and compiling life-history data from long-term studies of these species in the wild. Multi-variate analyses demonstrated that extensive brain growth, whether through prolonged duration or rapid growth rates, results in slow body-growth rates during the juvenile period and delayed age at maturity. In addition, encephalization results in longer adult lifespan. Therefore, this project demonstrated that intrinsic characteristics of anthropoid species determine the pace of their life histories.</p> / Dissertation

<p>Abstract</p> <p>Risky foraging is a male reproductive tactic in most polygynous mammals. It is speculated to result from intense intra-sexual reproductive competition. Consequently this behavior has been speculated to increase a male's reproductive competitiveness. However, individual males may differ in their propensity to take foraging risks. </p> <p>We therefore conducted a study on crop raiding behavior (a risky foraging strategy) in African elephants from the greater Amboseli ecosystem, in southern Kenya. We specifically examined the population sizes, gender and patterns of raiding elephants and investigated the effect of crop-raiding and genetic heterozygosity on male body size. We also examined the influence of age and genetic relatedness on observed patterns of association. Finally, we examined the role of life history milestones, association patterns and social structure on the acquisition of crop raiding behavior among wild free ranging male African elephants. With regard to the influence of association patterns on crop raiding behavior, we were specifically interested in understanding the mechanisms by which social learning might occur among male elephants.</p> <p>Our results showed that 241elephants from different populations in the ecosystem converged to raid farms. Approximately 35% of raiders were from Amboseli National Park, and the rest were other populations in the ecosystem. We observed only post-pubertal males but not females to raid. About one third of post-pubertal males from the Amboseli population were raiders. We found evidence of habitual raiding by some individuals. Crop raiding predicted post-pubertal male size, with raiders being larger than non-raiders. This result suggests that taking risks pays off for males. Our results also showed that other variables known to influence growth like genetic heterozygosity had no effect on size-for-age in male elephants, because low-heterozygosity males were rare. The probability that an individual male is a crop raider was greater for older individuals than young males. The probability that a male is a raider was greater when his two closest associates were raiders versus when they were not raiders and when a male's second closest associate was older, versus when his second closest associate was of similar age or younger. These results suggest that increasing energetic demands associated with life history milestones and social learning play a significant role in the initiation of crop raiding behavior. Raiders did not cluster into separate social units from non-raiders, probably due to the nature of social learning exhibited by this species and due to the diffuse nature of male elephant social units.</p> <p>These results have implications for understanding the evolution of risky foraging behavior in males, and for understanding the role of kin selection, dominance hierarchies and social learning in male elephant social systems. Results also have implications for understanding the spread of adaptive complex behavior in natural populations.</p> / Dissertation

Sailfish, Istiophorus platypterus, are commonly taken by the recreational and commercial fisheries in the Gulf of Mexico (Gulf) and larvae are frequently reported in the region, indicating the Gulf's potential role as spawning and/or nursery ground of sailfish. Five ichthyoplankton surveys were conducted in shelf and slope waters of the northern Gulf during the summers of 2005 (May, July, September) and 2006 (June, August). Surveys were conducted off the Texas and Louisiana coasts from 27 - 28N and 88 - 94W. During the two year study, 2,426 sailfish larvae were collected, ranging in size from 2.0 - 24.3 mm standard length (SL). Sailfish larvae were collected in 45.0% of collections with a peak density ranging of 51.5 larvae per 1000 m-2 of water sampled, and the highest larval abundances were observed within frontal features of the Loop Current. Sagittal otoliths were extracted from 1,236 larvae, and otolith microstructure analysis indicated sailfish ranged in age from 5 - 25 days post-hatch. Hatch-date distributions indicated fish were from early May to mid September spawning and/or hatching events. Instantaneous growth coefficients (g) ranged from 0.113 to 0.127 with intra- and inter-annual variations in growth observed. Growth coefficients correspond to a 10.7 - 11.9% increase in length per day. Instantaneous daily mortality rates (Z) were estimated from regressions of the decline in loge-transformed abundance on age and ranged from 20.4% to 29.2% per day suggesting large losses during the early life interval. Instantaneous weight-specific growth coefficients (G) ranged from 41.5% to 45.9% per day and were indexed to daily mortality to assess intra- and inter-annual variation in recruitment potential. Recruitment indices > 1.0 were observed during all surveys, suggesting cohort biomass was increasing and that conditions were favorable for growth, survival and recruitment. The results of this study indicate that the northern Gulf represents viable spawning and nursery habitat of sailfish and the sustainability of Atlantic sailfish populations may be linked to spawning in the Gulf.

The salamander family Sirenidae is composed of two extant genera, Siren and Pseudobranchus, each with two known species. Several questions regarding Sirenidae life history persist, and much of the available life history data for Pseudobranchus are attributed to studies of P. axanthus in northern Florida. Information on the reproductive biology of P. axanthus is limited, and historical references often suggest contradictory results. This study was undertaken to clarify information and expand on the limited data regarding P. axanthus reproductive biology, specifically for southern Florida populations. The study population was most likely the P. a. belli subspecies. P. axanthus in southern Florida exhibited year round, continuous reproduction with oviposition documented in nine months. Potential clutch size was positively correlated to female size. The largest observed potential clutch was a female with 58 pre-ovulatory oocytes. The largest observed bout was a female with 15 oviductal eggs. Female P. axanthus in southern Florida oviposited eggs singly and at total densities of 3-4 eggs/m2. Developmental time to egg hatching lasted about 30 days, larvae hatched at 16mm TL, and minimum size at female sexual maturity was 115mm TL and 72mm SVL. The reproductive biology of P. axanthus was distinctly contrasting to other members of the family Sirenidae, S. intermedia and S. lacertina, that occupy the same habitat at the same study location.

My dissertation study is two-year interdisciplinary project that combined case study and oral history methods to craft the life history of West Middle School. The goal of this project is to gain knowledge of how a school's identity, image and culture are shaped by outside forces such as education policy and demographic shifts over time. To this end, I ask teacher participants to narrate the life history of West Middle School, while paying particular attention to shifts in educational policy, to a changing student population and to citizenship education. The aim of exploring these issues is to present a holistic view of schooling. My theoretical framework draws upon the theories of figured worlds, hidden curriculum and social reproduction as entry points for understanding the complex world of West Middle School. I use case study methods such as observation along with oral history interviews and archival data to construct West's life history. The data sources include teacher interviews, an extensive yearbook archive, district school board meeting minutes, and school district boundary maps. The findings of the study are presented in two chapters. Chapter five presents key themes from the teachers' interviews describing the cultural environment and public image of West Middle School. Teachers characterize the school's image and reputation in terms of exceptionalism and the school's identity in terms of family and guardianship. Chapter six discusses citizenship education at West. The main themes in this chapter draw attention to teachers' understanding of good citizenship in pointed terms of respect, responsibility and civic duty. Central conclusions include a nuanced understanding of contradictions within the West Middle School community, the ways in which diversity is simultaneously valued and assimilated, and the ways in which West's positive reputation acts as social and cultural capital. Implications for teacher education include creating spaces where pre-service teachers can engage in deeper learning about school communities and coming to see teaching as a political rather than passive act. Finally, implications for research call for expanding methodological frameworks to include bending and combining methods toward gaining a rich understanding of the complexities of schools. / text

This thesis investigates the impact of avian malaria (Haemosporidia) parasites on the outcome of interspecific competition between two closely related bird species, pied (Ficedula hypoleuca) and collared (F. albicollis) flycatchers. I further investigated how variation in timing of breeding, life history strategies and immune competence genes (MHC genes) modulate the fitness effects of malaria parasites in one of the two species i.e. collared flycatchers. Collared flycatchers colonized the Baltic island Öland in the late 1950-ties and has since then been expanding their breeding range while competitively excluding pied flycatchers from the favourable habitats (deciduous forests). I investigated the underlying mechanisms behind this exclusion by combining detailed long-term breeding data with modern molecular genetic techniques identifying both the presence/absence and lineage specificity of haemosporidian blood parasites. I found that the rapid decline of pied flycatchers can be explained by the combined effects of competition over nestling sites, hybridization and haemosporidian infections. Haemosporidian infections have a negative impact on survival of pied flycatcher females but no detectable effect on collared flycatchers’ longevity or reproductive success. This may be due to the fact that collared flycatchers carry (and are potentially exposed to) a higher diversity of parasites than pied flycatchers, which in turn may select for a higher diversity of MHC genes and hence a better overall protection from the negative impact of parasites. Indeed, functional MHC diversity correlates negatively with malaria prevalence among collared flycatchers from Gotland. Moreover, I found that both, malaria infection intensity and immunoglobulin level influences how infected collared flycatchers respond to increased nestling food-demands. The latter results mean that there is variation in allocation strategies (i.e. in resource allocation between reproductive effort and immune competence) within the collared flycatcher population. Hence, this population has the ability to respond to novel selection pressures in terms of optimal allocation of resources into immune functions. In summary, my results show that local parasites may facilitate the expansion of a new colonizer. This is important in the context of global climate change that will probably increase the colonization rate of southern species and lead to novel host-parasite interactions.

Between individual behavioral variation has been described in nearly every animal taxa where it has been measured. Often, these behavioral variations correlate across contexts, forming a behavioral syndrome. Despite a recent push to better understand the origins and consequences of behavioral syndromes, there still is no cohesive framework that describes this phenomenon. Here, I develop a social insect species into a model for measuring and testing behavioral syndromes at a new level of biological organization; the colony. This builds upon the rich literature describing between-colony variation in behavior and provides novel insights into the evolution of behavioral syndromes. In my first chapter I show that colonies do not vary from one another in foraging distance, nor is foraging distance directly associated with colony size. This was my first step in demonstrating that colony behavioral variation is not simply a byproduct of colony size. In chapter two, I expanded upon this finding by testing colonies both in the lab and in the field for a variety of ecologically relevant behaviors. Here, I found that there was a behavioral syndrome that reflected foraging distance, foraging effort to novel and familiar resources, response to threat and aggression. While there is a gradient of phenotypes, some colonies either travel farther to forage for food and respond more aggressively when confronted with a conspecific invader, but appear to invest less in each given incident or food source. I consider this to be more risk-tolerant; they increase their risk of external mortality for potentially larger pay-offs. On the other hand, risk-averse colonies deploy more foragers to exploit closer resources, increase their overall activity in the response to threat, but avoid travelling farther distances or aggressively engaging invaders. Additionally, there is between population variations in risk-taking phenotype. Across the western United States, colonies at more northern latitudes are more risk-tolerant than colonies at more southern latitudes. In chapter 3, I expand upon this latitudinal gradient in behavioral phenotype by investigating what ecological factors predict a colonies level of risk-tolerance. Specifically, I focused on ecological traits that reflected predation, competition, food resource availability and abiotic stress. I found that competition for nest sites and spatial clustering predicted behavioral type; colonies at high levels of nest site competition or spatial clustering were more risk-tolerant than colonies at lower levels of competition or were more spatially dispersed. In chapter 4, I used a common garden and brood transfer experiment to investigate if the relationship between the ecological environment and behavior was the result of phenotypic plasticity or local adaptation. I show that local adaptation is the most likely explanation, as colonies with more workers from the donor colony are more, behaviorally, like the donor colony than colonies with fewer donor workers. In chapter 5 I test if the risk-taking behavioral syndrome is the result of life history strategy variation. I test the growth rate and energy allocation towards either somatic effort or reproductive effort. I found that colonies which are risk-tolerant also grow faster and dedicate more energy towards reproductive effort, which is consistent with predictions built from life history theory. This body of work shows that behavioral syndromes can exist at a new level of organization, the colony, and that variation in behavioral type is the result of differential selection pressure between populations. This directly connects behavioral syndrome research to life history strategy research. As life history strategy theory is a well-understood field, this represents a true advancement in the field of behavioral syndromes.

Despite the association of the first pottery with food production and sedentism, case studies show hunter gatherers with different degrees of sedentism commonly adopted ceramics. Monagrillo ware (∼ 4500-3200 BP), central Panama, early in Central America, was made by egalitarian slash and burn farmers, cultivating domesticated seed and root crops. People occupied inland rockshelters and coastal shell middens. Their degree of sedentism is debated. It is unclear whether they were sedentary both in the inland and the coast exchanging resources or whether inland people visited the coast during dry periods. Their pottery functions are not well understood. I provenanced and studied production processes and diagenesis of Monagrillo pottery combining life history approach and archaeometric methods. I assessed the degree of sedentism of people and inferred vessel functions producers expected. I studied diagenesis because it probably affects analytical results. My study showed that pottery was produced and used in the foothills and on the coast, possibly, in the plains, of the seasonally dry Pacific side of Panama. This suggested that people were sedentary in areas surrounding Parita Bay. Vessels from the Pacific foothills were transported to perennially wet Caribbean slopes; where production was difficult due to precipitation. According to technical choices made, I infer that potters in the Pacific foothills opted for useful and dependable designs, for cooking. Transportability and resistance to weathering were also important. Pacific coastal producers may have chosen designs for cooking-related attributes, but not transportation. Finally, a Pacific plains intermediate site had a high proportion of vessels from both the Pacific foothills and the coast and had a high proportion of decorated sherds. This site may have had special functions such as for meeting, feasting, and exchange. All producers shared manufacturing techniques indicating relatedness. Sherds excavated from the Caribbean zone and the Pacific coast had different diagenetic patterns suggesting climatic differences; this identification helped source pottery. My work contributes to knowledge about pottery origins and degrees of sedentism, technical choices made to reach functional needs, and climatic impact on production and post-depositional changes.

No description available.