This thesis examines how Eastern grey squirrels, Sciurus carolinensis, modify their foraging and hoarding behaviour in relation to different risks, particularly those which involve a trade-off between securing food resources and avoiding a negative outcome with a competitor. While foraging for food to eat and hoard, squirrels must compete with conspecifics and heterospecifics for access to resources, and they must ensure the safety of their food hoards from onlookers or opportunistic pilferers. While engaging in these behaviours in the most efficient way, they must also avoid being predated upon. Five studies were conducted to further understanding of grey squirrel foraging, hoarding and pilferage behaviours, and how they are affected by different risk factors. The data in this thesis provide experimental evidence that grey squirrels respond directly to conspecific presence as a cue of pilferage risk and adjust their behaviour in ways that may help to reduce cache theft. The data also support the view that conspecific and heterospecific competitors pose risks to foraging and caching, with squirrels modifying their behaviour in ways that serve to avoid negative competitive interactions. Predation risk was found to be particularly disruptive to foraging behaviour, and it also had a seasonal effect upon pilferage rates of experimenter-made caches. A variety of strategies that squirrels might use to pilfer caches were investigated, however, the data did not provide a clear indication of pilferage strategy used by squirrels; they did not seem to use observational spatial memory, and they did not simply pilfer in profitable foraging locations. This thesis raises questions about the mechanisms grey squirrels use to assess pilferage risk and how they engage in pilferage in comparison to other caching species; the studies conducted illustrate different methods that future research could use to investigate food hoarding and pilfering behaviour in wild and captive squirrels.

This thesis considers the importance of adding stochasticity to models of optimal foraging behaviour. The problem is divided into two elements, risk and information, which are treated separately. Part One: Risk. The theoretical and empirical results concerning animal preferences in risky situations are reviewed. Animals are known to show both risk-averse and risk-prone preferences over food reward. It is shown, theoretically, that a simple optimality model mimimizing the probability of death due to starvation accounts for at least some of the observed patterns of preference. The model is generalized to consider preference from arbitrary combinations of mean and variance. Three limitations of the model are treated in detail, that is the importance of starvation by "ruin", mind-changing about risk preferences, and energetic carry-over are discussed. The implications and limitations of these models are outlined. Part Two: Information. The theoretical literature is reviewed, and the problem of information is divided into three elements. A simple model of environmental tracking is studied. The model suggests that there is a trade-off between sensitivity to change and the costs of sampling. The model is tested using great tits (Parus major) foraging in an aviary. The trend in sampling was as predicted, but the birds were less sensitive to change than predicted. The problem of patch sampling is critically discussed. The value of sampling is defined, and this definition is used to compare the assumptions of previous models. Three such problems are treated: the importance of variance in the mixing distribution of patch sub-types; the importance of alternative and unambiguous patch types; and the importance of patch depression. It is concluded that previous models have often over-valued sampling. A simple and natural model of partial patch recognition is considered, and is shown to have empirical support. Implications and limitations of these models of information are discussed.

Supplementary food is less variable than natural food. While feeding from constant food sources tends to be preferred by animals they must sometimes forage from more variable resources. However, the ways in which animals deal with the temporal and spatial variability of more natural food is not entirely understood. I investigated the decisions free-living rufous hummingbirds made when foraging from variable resources, where variability was encountered over time or within a bout via four field experiments. In addition, I investigated their use of wild flowers and differences in the use of supplementary food by these birds in different regions using surveys and by manipulating the distribution of feeders at feeding sites. I investigated the possibility of a genetic explanation for any differences in feeder use between regions using analysis of microsatellite DNA and banding data. Hummingbirds seemed to prefer to make foraging decisions based on past behaviour or post-ingestive feedback rather than on sensory information such as taste, which may be harder to assess accurately. Birds choosing between constant and variable rewards with equal means preferred the constant rewards when variability was high but tended to prefer the variable reward when variability was low. This seems to be a result of hidden time and other costs associated with foraging on highly variable resource but not on less variable ones, combined with potential benefits of information seeking from less variable resources. In addition, these preferences between constant and variable resources were affected by preceding foraging conditions. The number of birds using feeders was affected by population density and air temperature. Microsatellite data showed the rufous hummingbird population to have a fairly panmictic population structure. Investigating influences on foraging decisions at a large scale (population density) and small scale (resource variability) has provided a much wider understanding of their foraging behaviour than either could alone.

Seabirds are vulnerable to a wide range of impacts at sea and function as important indicators of ocean health. A detailed understanding of their movements and distributions at sea, as well as the types of behaviour in which they engage and the extent to which those activities make them vulnerable to different impacts is critical in effective conservation planning. But their elusive lifestyles and mobility have hampered studies of their at-sea behaviour. Using miniature data loggers deployed on Manx shearwaters Puffinus puffinus this thesis explores the movements, distribution and behaviour of a small-medium pelagic, procellariiform seabird during foraging trips at sea. Foraging distributions were most variable during the pre-laying period when females departed the colony to build their egg. Females foraged close to the colony when local resources were adequate, but more typically foraged in distant shelf edge waters. Males returned frequently to the colony during this period and typically foraged close by, but also in shelf edge waters when local resources were poor. During incubation and chick-rearing the foraging movements of birds tracked from up to four colonies showed considerable inter-annual variability, but were largely constrained to the Irish and Celtic Seas and the inshore waters of west Scotland. Birds from each of the colonies foraged in waters local to their own colony, but also in more distant locations, including the productive Western Irish Sea and Western Irish Sea Front where birds from multiple colonies co-foraged, presumably at high densities. At-sea behaviour was organized into three principal activities representing: (1) sustained direct flight, (2) sitting on the sea surface, and (3) foraging, comprising tortuous flight interspersed with periods of immersion and diving in pursuit of prey. Foraging was highly constrained to daylight hours during which birds engaged in bouts of diving separated by periods of flight or rest on the surface. Most dives were up to 6 m deep, lasting up to 13 s, but some much deeper dives (maximum 55.5 m) were also made. During chick-rearing the use of short and long duration trips may allow parents to control provisioning effort and their own body condition. However, reducing parents’ requirement to provision their chick (by supplemental chick feeding) did not appear to alter the at-sea movements and behaviour of parents, suggesting that at-sea behaviour probably is controlled more by foraging conditions and prey distributions than by the nutritional demands of the chick.

Doctor of Philosophy / Department of Psychological Sciences / Gary L. Brase / Risky decision making occurs in both humans and non-human animals. For a large portion of the history of scientific investigation into human judgment and decision making, risky behavior has been viewed as flawed and irrational. However, the past several decades have seen advances in the view of human rationality. Scientists have suggested that, rather than using probability theory as the metric by which humans are judged as rational or irrational, human minds should be evaluated with respect to specific ecologies (e.g., Gigerenzer & Selten, 2001) with some scientists going further and specifying the ecologies as those which our ancestors evolved; essentially, our minds and their decision processes are adapted to solve specific recurring problems, and to solve those problems in specific environments. Within the domain of risky decision making there are a number of theories and models which are consistent with the hypothesis that human (and non-human) minds are molded for specific behavioral patterns based on environmental cues. One example is the priority heuristic. The priority heuristic is based in the ecological rationality approach—that heuristics are designed for specific ecologies. However, the ecological rationality of the priority heuristic is underspecified. Studies One and Two of the present dissertation compared predictions made by two models of risk-taking from evolutionary biology and behavioral ecology (dominance theory and risk-sensitive foraging) with a variety of predictions made by the priority heuristic. Data clearly showed that risk-sensitive foraging outperforms the priority heuristic (Study One) and that the priority heuristic cannot account for the motivation to acquire a minimum number of resources. Study Two showed mixed results for the priority heuristic when compared to dominance theory. Specifically, choice patterns were consistent with the priority heuristic, but process data in the form of decision times were not consistent with the priority heuristic. Also, the data pointed to a strong effect for desiring higher status when competing against others of varying status. Study Three compared four potential models of risky decision making in an attempt to extend the pattern of results from Studies One and Two showing general risk-sensitivity when attempting to achieve a specified need level (Money for Study One; Status for Study Two). Also, Study Three attempted to clarify the scope of the pattern of general risk-sensitivity by examining differential patterns of results based on whether the models predicted motivations to achieve need levels for money, status, or both. Results from Study Three were consistent with a general model of risk-sensitivity which operated on both monetary need levels and status need levels. This effect was additionally ubiquitous for males and females, contrary to predictions by dominance theory. The data from three studies showed support for a general model of risk-sensitivity consistent with those proposed by others (Mishra, 2010). The concept and implications of this general risk-sensitivity model are discussed, as well as future directions to understand the finer details and potential scope of this particular general risk-sensitivity model.

Student Number : 9613963J - PhD thesis - School of Animal, Plant and Environmental Sciences - Faculty of Science / Animals living in cold environments show physiological, morphological and behavioural adaptations to low temperatures. The African ice rat, Otomys sloggetti robertsi, which is endemic to the southern African Drakensberg and Maluti mountains above 2000m, is an interesting exception since, unlike most alpine small mammals, it does not hibernate or display torpor and is physiologically poorly adapted to low temperatures. It is a strict herbivore, feeding on a low quality diet. Ice rats do show some morphological (e.g. short tails) and behavioural (e.g. communal huddling; constructing underground burrows) adaptations, but little else is known about their biology, particularly how they maximise energy gain to meet thermoregulatory requirements, especially during cold periods. Since feeding represents the primary method of energy gain in endotherms, I studied aspects of the foraging biology of ice rats, including gut structure, foraging patterns and habitat choice. The gut structure of O. s. robertsi is well adapted for a high fibre, herbivorous diet and shows broad similarities with those of its mesic- and arid-occurring relatives. However, O. s. robertsi showed increased dimensions of several foregut organs which may be adaptations for increased energy uptake and/or poor diet quality in alpine environments. Furthermore, females had a larger stomach as well as a longer caecum, small and large intestine in summer than in winter but the gut of males was unaffected; such sexual asymmetry may be related to increased energy requirements of females during pregnancy and lactation. Environmental influences on the aboveground behaviour of O. s. robertsi were investigated by recording the duration of behaviours as well as sequential transitions among behaviours. Ice rats spent most of their day foraging and basking, and much time was spent in their underground burrows. Seasonal comparisons revealed that ice rats spent significantly more time acquiring energy through foraging in winter, whereas they remained below ground for longer periods of time during the middle of the day in summer to escape extreme heat and solar radiation. To understand how low temperatures and predation influenced foraging patterns, the behaviour of ice rats was studied in summer and winter in a population where predators were minimal and in another population which experienced higher levels of predation. Ice rats are central place foragers that travel short distances to forage and display significant seasonal variation in their foraging patterns. In the absence of predation risk, ice rats generally returned to a central place with forage, even though returning to a burrow after foraging in winter was energetically costly. However, these costs must be weighed against the benefits of avoiding exposure to low temperatures by feeding under cover as well as the loss of collected food and possible injury associated with aggressive interactions with conspecifics. Under moderate predation pressure in both seasons, ice rats followed a central place foraging strategy to minimise predation risk, always returning to a burrow entrance with forage collected elsewhere. However, when no perceivable threat was observed, ice rats displayed ‘optimal’ foraging patterns in summer similar to those recorded in the absence of predation pressure and only returned to a burrow with forage as distance from that burrow increased, suggesting that ice rats display facultative foraging decision making in response to multiple environmental cues. The distribution of occupied ice rat burrows was correlated against several environmental factors to determine microhabitat requirements. Ice rat burrows were situated in close proximity to herbaceous and wetland plants, but away from woody vegetation, suggesting that habitat choice is related to the presence of food plants and reduction of shade, facilitating short travel distances during foraging as well as promoting basking. Despite the physiological shortcomings of ice rats, the gut structure, foraging behaviour, and habitat choice of the taxon are adapted for life in cold alpine habitats, most likely by maximising energy intake. Similarities in foraging behaviour and habitat use between O. s. robertsi with its closely-related arid-occurring relative Parotomys spp. suggest phylogenetic influences, but it is possibly more a reflection of similar phenotypic responses to the extreme habitats inhabited by these otomyines.

Este trabalho foi dividido em dois capítulos em formato de artigo científico, que fornecem informações sobre diversidade e ecologia de vespas sociais (Polistinae) em três áreas de floresta amazônica no estado de Rondônia. No primeiro capítulo comparamos índices de diversidade de áreas com diferentes níveis de interferência antrópica e apresentamos uma lista de espécies para a região. No segundo observamos a relação de alguns fatores ambientais abióticos (temperatura, umidade relativa do ar e intensidade luminosa) com o forrageio das vespas sociais durante a fotofase (06:00 18:00 h). Foram realizadas 42 coletas ativas com auxílio de solução atrativa (água, sal, açúcar), totalizando 504 horas de coleta de dados. Foram coletadas 2983 espécimes de vespas sociais, distribuídas em 76 espécies de Polistinae, sendo um dos trabalhos com maior diversidade de vespas sociais coletadas no Brasil. As vespas mais abundantes foram Agelaia Lepeletier e com maior riqueza de espécies Polybia Lepeletier. A área com maior interferência antrópica teve os índices de diversidade similares aos da área com menor interferência, com isto, concluímos que a diversidade de vespas sociais (Polistinae) não é um bom parâmetro para indicar o nível de preservação ambiental de fragmentos de floresta, uma vez que estes resultados já foram observados em áreas de Mata Atlântica. Quanto aos fatores abióticos, apenas a temperatura foi significante (P<0.05) e observamos que as atividades de forrageio de Polistinae ocorrem durante todo o período da fotofase, não priorizando horários específicos. / This study was divided into two chapters in format of scientific papers, which provide information about ecology and diversity of social wasps (Polistinae) in three areas of Amazon rainforest in state of Rondônia. In the first chapter we compare diversity indices of areas with different levels of human interference as well show a list of species for the region. In the second we present the relation between the abiotic environmental factors (temperature, relative humidity and light intensity) during the photophase (06:00 to 18:00 h) with the foraging of social wasps through statistical analysis. This study was conducted using active collection with an attractive solution (water, salt, sugar) in 42 collections, totaling 504 hours of data collection. We collected 2983 specimens of social wasps, distributed in 76 species of Polistine, being a survey with the greatest diversity of wasps collected in Brazil. The more abundant wasps were Agelaia Lepeletier and the greater richness was Polybia Lepeletier. Samples were taken in the area with the highest anthropogenic interference had diversity indexes near the area with less interference, it concluded with the diversity of social wasps (Polistine) is not a good parameter to indicate the level of environmental preservation of forest fragments, as well has been observed in surveys in the Atlantic forest. Regarding abiotic factors only temperature was significant (P<0.05), and we observed that the activities of Polistine occur throughout the entire photophase period do not prioritizing any specific times.

The migratory behavior of North Atlantic leatherback turtles (Dermochelys coriacea) has been documented in the Wider Caribbean, but the migratory movements of leatherbacks nesting in South Florida are relatively understudied. Our knowledge of their migrations is currently limited to ten nesting females tracked from the east coast of Florida that either moved north to the Northern Atlantic or east to the coast of Western Africa. These results bring to light the need for further investigation and larger sample sizes to identify and determine the relative importance of the different foraging areas for the leatherbacks nesting in South Florida. Here, I analyzed stable carbon (δ13C) and stable nitrogen (δ15N) values in whole blood and skin of leatherbacks nesting in South Florida between 2014 and 2017 to estimate the putative foraging origins of these nesters prior to coming to South Florida to nest. This study provides some of the first stable isotope inferences and insights into the variable pre-nesting foraging habitat locations of Florida’s leatherback population. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Uma população do opilião Serracutisoma pseudovarium utiliza a Pousada Esquilo do Parque Estadual Intervales (PEI), São Paulo, Brasil, como abrigo. Os animais se escondem em frestas na edificação e saem à noite para forragear, principalmente pelas paredes da construção. Essa situação constituiu uma oportunidade única de se realizar um estudo detalhado de forrageio e uso do espaço por opiliões, sendo este o primeiro objetivo deste trabalho. Além deste local, também foram acompanhados mensalmente, ao longo de 15 meses, outros quatro locais do PEI: Pousada Onça-Pintada, Castelinho, Toca dos Meninos e Gruta Detrás. Em cada um destes locais (com exceção do Castelinho), os animais foram marcados individualmente e foram realizadas medidas corpóreas. Desta forma, foi possível efetuar também um estudo populacional, que constituiu o segundo objetivo deste trabalho. Para analisar o forrageio em detalhes, um croquis da edificação foi elaborado, no qual os animais foram anotados de hora em hora, ao longo de uma noite, em cada um dos meses de coleta. Além do posicionamento do animal, também foram registrados sua marca e o comportamento exibido no momento da observação. Assim, o terceiro objetivo foi realizar um estudo comportamental através de um etograma com dados obtidos em campo, ao longo do ano inteiro. No total, 380 indivíduos foram marcados, sendo 192 na Pousada Esquilo, população foco do estudo. Destes, 71 foram fêmeas, 71 foram machos e 50 foram jovens. O tamanho estimado da população, pelos modelos de Fisher-Ford e Jolly, variou de 36 a 95 indivíduos. A análise dos deslocamentos ao longo do forrageio mostrou que os animais mesclam uma estratégia de emboscada com períodos de deslocamento, em que podem encontrar ativamente uma presa. Não foram encontradas relações entre a frequência de utilização destas estratégias e o sexo, idade ou estado nutritivo/reprodutivo dos animais. Porém, o mesmo indivíduo tendeu a repetir a mesma estratégia em diferentes noites de forrageio. Da mesma forma, a direção do deslocamento tendeu a ser repetida, embora os animais não utilizem trilhas marcadas individualmente ou coletivamente. Etogramas obtidos com dados de campo são raros, e possuem a vantagem de não serem influenciados por fatores como maior densidade de animais e disponibilidade de alimento, comuns em estudos em cativeiro. A comparação de etogramas de machos, fêmeas e jovens não mostrou grandes diferenças de comportamento entre os grupos / A population of the harvestman Serracutisoma pseudovarium uses a building (Pousada Esquilo in the Intervales State Park) as a shelter. The animals hide in crevices of the building during the day and leave at night to forage, walking mainly on the walls of the same building, which is situated inside the forest. This situation appeared to be an unique opportunity to perform a detailed study of foraging dynamics and use of space by harvestmen, which constituted the first objective of this study. In addition to Pousada Esquilo, four other places of the Park were monthly monitored during 15 months, namely: Pousada Onça-Pintada, Castelinho, Toca dos Meninos cave and Detrás cave. In each of these places (except Castelinho) the animals were marked individually and body measurements were taken. This also allowed the conduction of a population study, as the second objective of this study. In order to examine the foraging dynamics in detail, we made a croquis of the building, in which the animals were recorded hourly during one night of each sampling event. In addition to the position of the animal, its individual mark and behavior at the moment of the observation were also recorded. This behavioral study led to the third objective, which was the construction of an ethogram based on the field data collected throughout the year. A total of 380 individuals were marked. In Pousada Esquilo, the target population of the study, 192 animals were marked, being 71 females, 71 males, and 50 juveniles. The size of the population estimated by both Fisher-Ford and Jolly models varied from 36 to 95 individuals. The study of displacement during foraging showed that the animals combine an ambush strategy with periods of walking, when they might actively find a prey. No relation was found between the frequency of usage of each strategy and sex, age or nutritional/reproductive condition of the animals. However, the same individual tended to repeat a strategy in different nights. In a similar way, the direction of the movement tended to be repeated, although the animals did not use individually or collectively marked trails. Ethograms elaborated with field data are rare in the literature, and they have the advantage of not being influenced by factors as higher animal density and food availability, which are common in studies made in captivity. The comparison among ethograms of males, females and juveniles did not show great behavioral differences between the groups

Many canids live within hierarchical social systems that could promote differences in learning or in behavior between ranked individuals. Differences in foraging and territorial behavior have been observed between ranked coyotes (Canis latrans), yet effects of learning and social status on coyote behavior are not thoroughly understood. I explored a) coyote response to an artificial scent boundary and whether response differed by status, b) how foraging coyotes tracked temporal resource change, and c) how coyotes find spatially distributed food, and the effect of dominance on foraging behavior. I used male/female pairs of captive coyotes at the National Wildlife Research Center Predator Research Facility in Utah. Prior to testing, I identified social rank within pairs by testing for food dominance. In study 1, I laid a scent boundary and monitored space use with GPS and observed behavioral responses directly. All coyotes investigated and crossed the boundary, but were repelled more by human presence. Subordinates investigated and marked the boundary more than dominants. Further investigation is needed to mimic natural boundaries for management purposes. In study 2, I gave eight individual coyotes an operant test with concurrent variable interval (VI) schedules. I varied the ratio of resources and measured the time spent on two choices, then fitted the generalized matching equation to the data. I found that all coyotes efficiently tracked changes in resource ratios and matched their relative rate of foraging time to relative rate of resources. Matching theory provides an effective methodology to explore foraging strategies and behavioral flexibility in coyotes. In study 3, I tested 16 coyotes in a spatial foraging task. Coyotes searched for food in eight potential locations, and were tested individually and in respective pairs. I recorded the area and number of locations searched, approach time, and frequency of marking by dominant and subordinate coyotes. Results showed individual subordinates increased efficiency by relocating, but their efficiency decreased when foraging in pairs. Dominant coyotes did not increase efficiency in company by following subordinates. Coyotes marked the correct feeder more than incorrect feeders. Results suggest coyotes use memory and odor (scent marks) to find food, but that social status overrules information use.