<p>Sea turtles are long lived marine species that are currently endangered because their life history and population dynamics hinder them from withstanding modern anthropogenic threats. Worldwide, fisheries bycatch in on the major threats to the survival of sea turtles and that is also the case in the Eastern Pacific. To establish regional conservation priorities for the mitigation of bycatch, it is essential to first obtain a comprehensive picture of the regional sea turtle bycatch situation. This comprehensive analysis was lacking for the Eastern Pacific; therefore one component of this dissertation (the first chapter) is focused on delivering a regional bycatch analysis for the Eastern Pacific. A literature review was conducted to obtain numbers of turtles captured, frequencies, bycatch and mortality rates per species and country in trawl, longline, and gillnet fisheries, and to compile results of mitigation measures. Moreover, estimates for current annual capture rates in trawl fisheries were obtained and compared with population numbers. </p><p>This regional bycatch used all the information compiled and synthesized to give conservation priorities at the regional level. The review underlines the high bycatch rates in trawls for Costa Rica, Guatemala, and El Salvador and the detrimental impact that these captures could have specially for hawksbill Eretmochelys imbricata due to its reduced population numbers and for green turtle Chelonia mydas due to its highest mortality rate. It also emphasizes the continuous lack of use of TEDs as a bycatch mitigation measure. In longline fisheries, the review identifies the high bycatch rates in pelagic longline fisheries of Costa Rica, Ecuador, and Nicaragua in a global context but given that olive ridley Lepidochelys olivacea is the most common species captured in these countries, it highlights the capture of loggerhead Caretta caretta and leatherback Dermochelys coriacea off Peru and Chile due to their small population numbers. Bottom longlines have high mortality rates compared with pelagic longlines in the region and the review identifies a need for further research in this area due to the scarce information but high mortality rates. The review also noted that some mitigation measures for pelagic longlines like circle hooks and hooks with appendages could bring improvements in the mitigation of bycatch in longline fisheries in the region, there is still considerable work to be done in technology transfer, sea turtle handling, and estimates of post-release mortality rates. </p><p>For gillnet fisheries, the most important highlight is how little information exists for the region given the high rates of bycatch for sea turtles in this gear. However, the difficulties of studying bycatch in highly dynamic and artisanal fisheries are recognized as the major impediment for this situation. Nevertheless, the high bycatch rates in areas where sea turtles congregate in high numbers like in foraging grounds for loggerhead in Baja California, Mexico and for greens in Paracas and Sechura, Peru, calls for either gear modifications (which has not been that successful), change of gear, or areas closed for gillnets. </p><p>The second half of the dissertation is focused on foraging ecology of oceanic sea turtles in the Southeast Pacific Ocean. Sea turtles in the oceanic stage are the least known stage due to the difficulty of accessing these individuals. However, it is a very important stage in the life cycle and can be critical for the population dynamics of sea turtles as some population models have shown. Therefore, this dissertation is filling a gap in the life cycle of sea turtle populations in the Eastern Pacific. </p><p>To study foraging ecology, we used Stable Isotope Analysis (SIA) of turtle tissues as well as potential prey items from the oceanic realm. SIA is a great tool because it gives an integrated view, from days to weeks, of prey from a consumer tissue. SIA also can be used to link consumers to habitats when elements that have spatial trends are used. In chapter two, we investigate the foraging ecology of three species of sea turtles to compare trophic status and to observe if spatial patterns were shown in the SIA signatures of sea turtles. To our knowledge this is the first study employing SIA to research the ecology of three species of sea turtles from the same time and space. Our results show that spatial patterns in delta15N and delta13C were observed in sea turtle's tissues as correlations with latitude. We also found that loggerhead's signatures differed significantly from green and olive ridleys, especially in terms of delta15N. Loggerheads had higher values of delta15N and also a wider nitrogen trophic niche. Greens and olive ridleys were similar in isotopic nitrogen values but they were significantly different in carbon. When analyzing a smaller group of animals captured in a more restricted area, nitrogen differences were not found which suggests that latitudinal spatial patterns play an important role in the nitrogen signature. On the contrary, carbon signatures still differed among turtles in the restricted area which suggest that the inshore-offshore trend is strong and made us conclude that loggerheads are restricted to oceanic areas but that greens and olive ridleys could be using both coastal and oceanic areas.</p><p>In chapter three, we conduct a mixing model analysis using the Bayesian program SIAR to identify the most important prey items for green, olive ridley, and loggerhead off Peru. Also, we wanted to identify the contribution of longline baits in the diet of oceanic turtles. The analysis was restricted to the central zone of our study area to avoid spatial trends in nitrogen. To use as sources in the model, we collected potential prey items offshore Peru during trips on longline fishing vessels and obtained their stable isotope signatures. Results from our mixing models show that for greens and olive ridleys, crustaceans, mollusks, and coastal Ulva (indicator of coastal prey) were the only important food items. In the case of greens, crustaceans had a very high proportional contribution and due to the fact that nitrogen values of crustaceans were the lowest ones among the sources it seems that greens would be eating in a lower trophic level. The importance of coastal Ulva for greens and olive ridleys is a confirmation of our findings from chapter two where we suggest that these two species could be using oceanic as well as coastal areas. </p><p>Results for loggerheads showed cnidarians, mollusks, mackerel and squid bait as foraging items and highlights the differences among this species and the other two. The lack of importance of coastal Ulva again suggests that loggerheads remain only in oceanic areas off Peru. Moreover, the importance of mackerel and squid, the most common longline baits, suggests this species is the one interacting the most with longline fisheries and that cumulative effect of multiple interactions could have a detrimental effect in this population.</p> / Dissertation

Northern bobwhites (Colinus virginianus) are a valued game species that have seen massive population declines in the last few decades. This decline has been attributed to many factors including predation, the topic of this study. I examined the habitat selection, nocturnal movement and potential rate of encounter with quail nesting locations by coyotes (Canis latrans), bobcats (Lynx rufus), and raccoons (Procyon lotor) at the Rolling Plains Quail Research Ranch, a private 19 km2 ranch in the Rolling Plains ecoregion of west Texas. My study had 2 objectives: (1) to compare the habitat use of mesopredators in the Rolling Plains to the nesting habitat of bobwhites, and (2) to characterize the nocturnal paths of these mesopredators and measure their overlap with quail nesting locations. I placed GPS collars on 4 bobcats, 7 coyotes and 11 raccoons during the quail nesting seasons of 2009-2011. I used the chi-square test as well as a modified version of the Ivlev’s Electivity Index (1961) to calculate habitat selectivity. I also measured the proximity of the mesopredators and quail nesting locations to roads, water and quail feeders on the ranch. I used fractal analysis to calculate length and tortuosity of nocturnal paths and assessed potential risk to quail nests by determining the intersection rates of mesopredator paths with quail nesting locations. I found that a large difference existed in selectivity of habitat between bobwhite nesting locations and the bobcats and raccoons. Bobwhites selected for the upland grasslands and shrubs and against rocky ridges. Bobcats selected for riparian zones, while raccoons selected for both riparian zones and rocky ridges, neither of which were selected for by nesting quail. Bobcats and male raccoons additionally showed a propensity for road travel, which quail often nested close to. Coyotes selected strongly for grasslands, utilized their home ranges comprehensively and showed a preference for road usage, and thus had the greatest potential encounter rate with quail nest sites. However, coyotes also showed the most linear and direct movement pattern, potentially reducing their efficiency in finding quail nests. This study indicates that coyotes potentially present the largest threat to the nests of quail and female raccoons the least. Management decisions such as the levels of management needed for the 3 species of mesopredators are discussed.

Effective population management of green sea turtles (Chelonia mydas) necessitates understanding the temporal variation in foraging grounds used in ontogenetic stages, and the effect that the assimilated diet within those habitats has on nutritional gain, growth and eventual reproductive output. Texas coastal waters provide foraging grounds critical to meeting the nutritional needs of green turtles during early life history. To characterize temporal shifts in foraging strategy stomach contents combined with stable carbon (delta13C) and nitrogen (delta15N) isotopes of scute tissue were examined across size classes of stranded juvenile green turtles from the middle and lower Texas coast during 2007-2010. Findings from dietary analysis generally corroborated those from stable isotopes in scute samples. Results indicate green sea turtles exhibit multiple shifts in diet and habitat along the Texas coast. Although isotope values in the tissues of some <25 cm SCL turtles signified recent recruitment to jetty habitat, most in this size class exhibited depleted delta13C and enriched delta15N values indicative of oceanic life. Reinforcing oceanic occupancy from stable isotope results was forage material dominated by oceanic items such as Sargassum spp., Scyphozoa spp., and plastic debris. Diet analysis of 25-34.9 cm SCL turtles implied regional differences existed in macroalgae and seagrass consumption. Enriched delta13C and delta15N values in newest scute suggest most turtles inhabited the jetty environment, where macroalgae is the most available forage. A definitive shift by >35 cm SCL turtles to inshore seagrass habitat was revealed by a diet of seagrasses and tissue enriched in delta13C and depleted in delta15N. This is the first study to integrate stomach contents of several green turtle size classes with tissue analysis of stable isotopes. The combination of these techniques provided an assessment of the effectiveness of stable isotope analyses in documenting diet and habitat shifts. Stomach content examination determined the most recent diet consumed within the habitat occupied, whereas stable isotope analysis provided a time-integrated synopsis of diet and habitat shifts. Findings indicate integration of stomach content and stable isotope analysis is highly effective for characterizing habitat use and foraging strategy of ontogenetic-stage green sea turtles.

The current application of low persistence pesticides is unreliable for protecting wooden structures from termite attack. These applications may also pose an environmental and public health risk. Consequently, there is a need for the development of alternative systems to protect wooden structures from termites. Investigated here is the interaction between Australian termites, Coptotermes acinaciformis Froggatt, and to a lesser extent, Mastotermes darwiniensis Froggatt and Schedorhinotermes seclusus Hill, and a barrier system for protection of wooden structures. The aim was to develop an improved barrier for the protection of wooden structures that maximizes protection and minimizes environmental and health risks. Specifically, the performance of a barrier to protect wood against termite attack that incorporates a synthetic pyrethroid into polyurethane formulations is investigated. This research was conducted in parallel with other project contributors focusing on material science aspects of the research goals. A fundamental problem in assessing the value of termite barrier strategies lies in developing and interpreting laboratory assays that can deliver reasonable predictions of performance in the field. This is particularly the case with respect to the behaviour of termites over much longer periods in the field than can be undertaken in the laboratory. The approach to laboratory trials presented here is to define individual termite capabilities and, in combination with behavioural studies, to develop an understanding of factors which affect termite performance. The key experimental approach involved various laboratory based assays to evaluate termite foraging behaviour and performance against a range of barrier materials, progressing to field trials with the best performing material. Various species of termites; M. darwiniensis (Mastotermitidae), Cryptotermes primus (Hill) (Kalotermitidae), C. acinaciformis , Coptotermes frenchi Hill and S. seclusus (Rhinotermitidae), Microcerotermes serratus (Froggatt), Microcerotermes turneri (Froggatt) and Nasutitermes walkeri (Hill) (Termitidae) and Porotermes adamsoni (Froggatt) (Termopsidae); were investigated to determine the force that they can develop at their mandible tips. Larger termites can generate higher pressures on their mandible tips than smaller termites. By quantifying the mandible strength of a termite it was possible to contrast the capabilities of various economic termite species. Damage caused by an individual termite biting on synthetic materials was measured using electron microscope generated three dimensional models of indentations caused to the material. This was successful in quantifying the immediate capabilities of individual termites of different species. Most species were found to inflict a similar amount of damage to high density polyethylene. However M. darwiniensis caused much more damage than other species examined. Micro hardness testing was utilized to determine the relative hardness of pest termite mandibles. Termites were found to have mandibles much harder than any tested synthetic material. It was therefore found to be unrealistic to aim to develop barrier technology based on “harder than termite mandible material”. Trials using groups of termites in the laboratory demonstrated large differences in the performance of termites against various synthetic materials. There was a tendency for harder materials to suffer less damage. Mechanical properties of the barrier alone were found to be insufficient to stop termite damage. The resistance of polyurethane formulations incorporating insecticides to termite attack in the laboratory demonstrated a potential suitability for termite barrier technology. In behaviour trials, persistence of termite attack at the barrier face was found to be due not only to deterrent chemicals, but also to physical characteristics. Softer materials are not only easier for termites to remove but termites attack softer materials with greater tenacity, more termites spend more time attacking softer materials. Laboratory toxicity trials confirmed the bioavailability of Bifenthrin when incorporated within the barrier material and enabled the establishment of expected concentrations for effective protection. Termites were found to require direct contact with the barrier for mortality to occur. Trials designed to quantify repellence of the Bifenthrin in the barrier found that termites did not escape mortality by avoiding contact with the barrier material. As such pure Bifenthrin is shown to protect the barrier material directly by causing mortality rather than by repelling live termites away from the barrier. Field trials were conducted in northern Queensland where colonies of economic termites could be directly targeted. Wooden blocks were coated in polyurethane containing a range of Bifenthrin concentrations and trialed over an eight month period. Combination of the pyrethroid Bifenthrin in a polyurethane barrier at concentrations as low as 0.07% proved successful in preventing damage by the economically important termites M. darwiniensis and C. acinaciformis under high pressure field conditions. Only very small amounts of Bifenthrin migrated into adjacent soil, concentrations reached were in the order of 100 µg/kg of soil. For comparison the MLR for Bifenthrin in bananas for human consumption is 100 µg/kg. Bifenthrin in a polyurethane barrier could be used for the protection of houses and other wooden structures in the same manner as existing barrier film technology in order to minimise environmental and health risks associated with direct pesticide application techniques.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.

Meerkats are known to strongly rely on chemical communication in social contexts. However, little is known about their use of the sense of smell in food detection and selection. The aim of the present study was therefore to assess whether meerkats are able to (1) detect hidden food using olfactory cues, (2) distinguish the odour of real food from a single food odour component, and (3) build an association between the odour of real food and a novel odour. I employed the buried food test, widely used with rodents to assess basic olfactory abilities, designed to take advantage of the propensity of meerkats to dig. I found that the meerkats were clearly able to find all four food types tested (mouse, chicken, mealworm, banana) using olfactory cues alone and that they successfully discriminated between the odour of real food and a food odour component. In both tasks, the animals dug in the food-bearing corner of the test arena as the first one significantly more often than in the other three corners, suggesting development of an efficient foraging strategy. No significant association-building between a food odour and a novel odour was found within the 60 trials performed per animal. I conclude that meerkats are able to use olfactory cues when foraging and that their sense of smell is well-adapted for recognizing specific odours of behavioural relevance. To the best of my knowledge, this is the first study to successfully employ the buried food test with a carnivore species.

I investigated the differences in male and female foraging behavior of the african carpenter bee Xylocopa flavescens (Hymenoptera: Apidae). This species is important big pollinator in study area as observed. The pollen loads from the 20 male and 20 female bees were compared for the analysis of the foraging pattern. The principal differences and trends were found for the range of flowers visited by each sex.

Charnov's (1976) marginal value theorem has had success in predicting that animals will optimize net rate of gain when foraging in a patchy environment. The present study attempts to apply the marginal value theorem (MVT) to human behavior in a business setting in 3 Experiments. Businesses also attempt to optimize net rate of gain when choosing to discontinue one product in lieu of another using a product life cycle (PLC). Experiments 1 & 2 attempted to assess human behavior in a business context by varying time necessary to retool and monetary cost of retooling respectively. Experiment 3 attempted to add ecological validity by introducing variability to the PLC. The results of Experiments 1, 2, & 3 indicate that the MVT does not accurately predict human behavior in a business context, though methodological issues may have affected these results. Future research must be conducted in this area.

Doctor of Philosophy / Division of Biology / John M. Briggs / Anthony Joern / Foraging decisions by native grazers in fire-dependent landscapes reflect fire-grazing interactions. I assessed behavioral responses associated with the attraction of grazers to recently burned areas at multiple spatial scales. (a) I focused on feeding in the area between steps in a foraging bout – the feeding station – where forage quality and vegetation architecture underlie these fine-scale decisions. The ‘forage maturation hypothesis’ (FMH) predicts the distribution of large herbivores based on the temporal dynamics of forage quality and quantity, but does not address herbivore responses to inter-patch variation caused by fire-induced increases of forage quality. The ‘transient maxima hypothesis’ (TMH) also predicts variable forage quality and quantity, but in response to intermittent disturbance from fire. I described the effects of variable spring burn history to bison foraging and their spatio-temporal distribution at Konza Prairie. Forage attributes met predictions of the TMH to explain how forage maturation affects foraging behavior across watersheds with varying burn frequency. At sites burned in the spring after several years without burning, intake rate increased with increasing vegetation biomass at a greater rate during the early growing season than during the transitional mid-summer period. This foraging behavior occurred in response to a non-equilibrial pulse of high quality resource that set the stage in the burned area, and was then retained by repeated grazing over the growing season. Thus, bison responded increased forage resource availability resulting from transient maxima in infrequently-burned watersheds burned that spring and they intensely used these areas until forage availability and forage regrowth was not possible. (b) At the patch scale, bison selected areas of low-to-moderate grass cover in which to feed and avoided areas of high forb cover in the growing season. During the dormant season, however, bison selected feeding-sites with uniformly high canopy cover in watersheds that were not burned. (c) At the landscape-scale, infrequently burned watersheds (compared to watersheds that were not burned) provided the strongest significant predictor of bison space use in all early growing- and transitional-season months. (d) The probability of habitat selection was driven by availability of high foliar, protein and low-to-intermediate herbaceous biomass throughout the growing season. These results explain the hierarchy of foraging by a dominant consumer in an experimental landscape by linking two prominent hypotheses, TMH-FMH, proposed to explain spatial variation in forage quality and quantity at local and landscape scales.

Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-09-21T14:21:34Z No. of bitstreams: 1 DissAFB.pdf: 1628382 bytes, checksum: e0460959802ab641c95a2b8bfcc864c4 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-21T18:36:52Z (GMT) No. of bitstreams: 1 DissAFB.pdf: 1628382 bytes, checksum: e0460959802ab641c95a2b8bfcc864c4 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-21T18:37:08Z (GMT) No. of bitstreams: 1 DissAFB.pdf: 1628382 bytes, checksum: e0460959802ab641c95a2b8bfcc864c4 (MD5) / Made available in DSpace on 2016-09-21T18:37:15Z (GMT). No. of bitstreams: 1 DissAFB.pdf: 1628382 bytes, checksum: e0460959802ab641c95a2b8bfcc864c4 (MD5) Previous issue date: 2015-12-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Through the last decades, forest remnants were widely converted in crops and pastures, but the reintroduction of native trees offers the perspective of forests ecosystems restoration. This study aimed to investigate the recolonization by birds in riparian restored and reference sites, evaluating the effects of vegetation structure on avifaunal functional categories. We estimated vegetation structure by grass cover, tree density, total basal area, crown depth, height and diameter at breast height of each individual. We classified bird species by diet, foraging strata, nest height, dependence of cavities for nesting and forest dependence. To assess which characteristics were influenced by vegetation structure, we conducted canonical correspondence analysis, using as independent variables the three first axis of principal component analysis of vegetation variables, respectively related to canopy height, crown depth and stratification. We recorded 53 bird species in 326 registers. The avifauna of reference sites were richest and more diverse in all bird taxonomic descriptors. Canopy height influenced avifauna in relation to diet, foraging strata and forest dependence, and combinations of these functional traits also were affected by canopy height and crown depth. Species related to most open sites were granivorous or generalists with low forest dependence. Understory bird species occurred mainly in intermediate stages of vegetation growth, presenting middle forest dependence and more restrict diet. Insetivorous birds with high forest dependence characterized reference sites, with tallest vegetation. Our results emphasized the importance of considering functional traits of bird species on planning and evaluating recolonization of restored sites by birds. Considering the effects of riparian vegetation structure on bird assemblages, we suggest that reintroduction of plant life-forms other than trees for restoration purposes can accelerate both bird taxonomic and functional diversity across recolonization process. / Ao longo das últimas décadas, a cobertura por vegetação natural foi amplamente substituída pela agropecuária, mas a reintrodução de árvores nativas oferece a expectativa de restauração de ecossistemas florestais. Este estudo avaliou a colonização de áreas ripárias em restauração pelas aves, em relação a áreas de referência, testando a influência da estrutura da vegetação nas categorias funcionais da avifauna. Estimamos a estrutura da vegetação pela cobertura por gramíneas, densidade de indivíduos, área basal total, altura, profundidade da copa e diâmetro à altura do peito de cada indivíduo. Categorizamos as espécies de aves quanto à dieta, ao estrato de forrageio, à altura do ninho, à dependência de cavidades para reprodução e à dependência florestal. Para testar quais dessas características eram afetadas pela estrutura da vegetação, usamos a Análise de Correspondência Canônica, utilizando como variáveis independentes os três primeiros eixos da Análise de Componentes Principais da vegetação, respectivamente correlacionados com a altura do dossel, a profundidade de copa e a estratificação. Foram documentadas 53 espécies de aves em 326 registros. As áreas de referência foram as mais ricas e diversas em todos os descritores taxonômicos das aves. A altura do dossel influenciou apenas o tipo de dieta, o estrato de forrageio e o grau de dependência florestal. As combinações dessas três características também responderam à altura do dossel e à profundidade de copa. As espécies associadas às áreas mais abertas foram as granívoras e as generalistas de baixa dependência florestal. As aves do sub-bosque ocorreram principalmente em estágios intermediários de crescimento da vegetação, apresentando média dependência florestal e dietas mais especializadas. Espécies insetívoras de alta dependência florestal caracterizaram as áreas de referência, de maior altura de vegetação. Este estudo ressaltou a importância de considerar os aspectos funcionais das espécies e analisar conjuntamente vários deles no planejamento e na avaliação da recolonização de áreas restauradas pela avifauna. Considerando a influência da estrutura da vegetação ripária sobre a avifauna, nós sugerimos que a reintrodução de outras formas de vida na comunidade vegetal além do estrato arbóreo em ações de restauração pode acelerar o aumento da diversidade funcional da avifauna durante o processo de recolonização.