<p> Like many imperiled fishes, the endangered Pahrump Poolfish (<i> Empetrichthys latos latos</i>) is managed in <i>ex situ</i> refuges. I investigated life history characteristics of females from two such populations at Lake Harriet and Shoshone Stock Pond. Lake Harriet is a relatively large lake with low fish densities located at relatively low elevation and low latitude, while Shoshone Stock is a small pond with high fish densities at a higher elevation and latitude. Females from the Lake Harriet population were larger, and had greater fat content, reproductive allocation, and &lsquo;clutch&rsquo; size than females from the Shoshone Pond population. This divergence, which occurred in three decades, may result in a phenotypic mismatch if the fish are used as a source for restocking their native habitat or stocking new refuges. </p><p> Poolfish conservation may require establishing new populations; however, many sites are inhabited by non-native fish and/or other protected fish species. Thus, managers may wish to consider establishing multi-species refuges that may even already include undesirable species. I established experimental communities that included allopatric and sympatric communities of Poolfish, Amargosa Pupfish (<i>Cyprinodon nevadensis</i>), and invasive Western Mosquitofish (<i>Gambusia affinis</i>). Pupfish persisted in sympatry with both poolfish and mosquitofish, but had higher juvenile production when maintained in allopatry. By contrast, poolfish juvenile production was high in allopatry, but virtually absent in the presence of other species. </p><p> To evaluate the generality of these findings, I established experimental allopatric and sympatric communities of poolfish or pupfish with mosquitofish from two populations that differed in body size: Garrett mosquitofish were approximately twice the mass of Wabuska mosquitofish. Poolfish juveniles had high survival in allopatry, but produced virtually no juveniles when sympatric with either of the two mosquitofish populations. Pupfish juvenile survival was higher in allopatry than sympatric with Garrett mosquitofish, which in turn was higher than sympatric with Wabuska mosquitofish. These results were consistent with the earlier experiment suggesting that poolfish were functionally extirpated but pupfish maintained substantial production in the presence of mosquitofish. These findings suggest that poolfish should be maintained in single species refuges, but that multi-species refuges may protect imperiled pupfish species.</p>

<p> The white shrimp <i>Litopenaeus setiferus</i> is harvested throughout its range in the western Atlantic Ocean and is particularly important in supporting a commercial fishery in the northern Gulf of Mexico (nGoM) concentrated in Texas and Louisiana. Mortality rates of young (juvenile) white shrimp in estuarine nursery areas may have a large effect on the adult population. Understanding the temporal and spatial variation in mortality rates and other population parameters (i.e., density, growth rate, and secondary production) is important for the management of white shrimp in determining how estuaries function as nursery areas and can also be useful in identifying coastal habitats that best support white shrimp populations. My objective was to examine and describe the population dynamics, with a focus on mortality, of juvenile white shrimp populations in Sabine Lake, an estuary of the nGoM. I estimated density, growth, mortality, and secondary production in three areas along the estuarine salinity gradient. Most of these metrics were generally higher in areas of high salinity and total secondary production was relatively high in all three areas. Approximately half of the potential fish predators collected in my study area had preyed upon juvenile penaeid shrimps based on an examination of fish gut contents. Given their abundance within estuaries of the nGoM, these fish predators may have a large impact on populations of juvenile white shrimp. Mortality rates of juvenile white shrimp estimated with mark-recapture and length-frequency data were relatively similar to each other and within the range of the few values previously reported. Two commonly used age-based mortality estimators originally developed for fishes provided reasonably unbiased mortality rates for juvenile penaeid shrimps, although both estimators provided relatively high biased estimates at the lowest mortality rates considered. </p>

<p> Animals that live in groups face a dual challenge of effectively exploiting their environment while at the same time maintaining cohesion with other group members. Maintaining cohesion requires group members to come to consensus about when and where to move, despite the fact that they may not always agree. In this thesis, I investigate how individuals in groups make movement decisions, and how these individual decisions scale up to group-level properties. Using a laboratory experiment with golden shiners (<i>Notemigonus crysoleucas </i>), I first investigate the interaction network over which information spreads, finding that decisions are better predicted by whom individuals can see rather than whom they are close to, with potential consequences for the global spread of information (Chapter 2). I then investigate collective movement behavior in the wild using high-resolution GPS data from members of a troop of olive baboons (<i>Papio anubis</i>). I first show that baboons are consistent in the spatial positions they occupy within the group, and that the observed patterns may be understood based on a very simple mechanism by which individuals maintain cohesion with different numbers of their neighbors (Chapter 3). By quantifying how group members move relative to one another, I then show that baboon movement decisions are consistent with a shared decision-making process, rather than despotic leadership by dominant individuals, and that the patterns of decision-making are consistent with simple models of collective motion (Chapter 4). Finally, by incorporating a fine-scale, three-dimensional reconstruction of the habitat through which the baboons move, I show that habitat structure, in addition to social factors, also exerts an important influence on individual movement decisions, resulting in changes in the emergent structure and movement of the group (Chapter 5). Taken together, these results highlight that by combining high-resolution animal tracking, remote sensing, and analytical methods, we can begin to extend our understanding of collective animal movement from laboratory studies to complex animal societies living in the wild.</p>

<p> Community ecology investigates questions related to the density, growth/decline and movements of species over time in given geographical regions. This study investigated similar questions regarding communities of endemic bat species in Connecticut. White-nose syndrome (WNS) has recently killed millions of bats in New England, yet few large-scale conservation efforts have occurred in Connecticut and few data have been published on the status of Connecticut bats post-WNS. This study aimed to: 1) survey bats persisting in WNS regions to document whether changes have occurred in species biodiversity, richness, distribution and habitat use; and 2) measure seasonality effects from summer through pre-hibernal months. Bat presence and activity were recorded using bat detectors set in grassland and forested habitats, near bodies of water and near anthropormorphic and geologic structures across Connecticut. Bioacoustics data have been analyzed by using Sonobat^&copy; software. Combined, these data show that bat activity varies significantly across habitat type (p = 0.02) and over seasons (p = 0.05). Additionally, these data provide insight regarding relationships between individual species, and clumped species groups, with habitat types and across seasons. Ultimately, these data show how bat communities have changed over time in a post-WNS environment. Combined, these data can help drive future wildlife conservation, outreach, education and management practices.</p><p>

<p> Prey species defend themselves behaviorally and morphologically, and often utilize varied antipredator strategies against dissimilar predator types (i.e. terrestrial vs. aerial). Striped skunks <i>(Mephitis mephitis) </i> spray noxious secretions at predators and advertise this danger with deterrent behaviors and black-and-white aposematic coloration. Evidence suggests skunks are effective at deterring terrestrial mammalian predators but are vulnerable to aerial predators; how skunks assess the risk posed by different predator types, however, has not been examined empirically. I recorded the behavioral responses of skunks to audio playbacks of coyotes and great horned owls (the primary terrestrial and aerial predators of skunks, respectively), and peregrine falcons and white noise as controls, as well as to a visual remote controlled model. Skunks engaged in vigilance and running away more often in response to owl vocalizations, suggesting skunks perceive owls as more threatening relative to coyotes. Skunks were more likely to foot stomp and run away in response to the remote controlled model compared with coyote vocalizations, implying visual cues were perceived as more risky than audio cues. This study elucidates how a well-defended mammal can determine which perceived threat is most risky and alter its behavior when its main defense strategy is not successful against all predator types.</p><p>

<p> This thesis qualifies functional and ecological aspects of mucus trails deposited by <i>Elimia potosiensis</i> collected from the Meramec River. Freshwater snails are most often recognized for their significant role in river and stream ecosystem function as primary consumers and prey items. However, their form of locomotion is the most energetically expensive found in the animal kingdom. Found in large numbers and densities, <i> E. potosiensis</i> is capable of coating large swaths of substratum with carbohydrate- and protein-rich mucus. This has the potential to affect ecosystem function at the most basal trophic level both energetically, by contributing nutrients and energy to the surrounding water body, and functionally, as a sticky substance to which microheterotrophs become adhered. </p><p> In marine studies, researchers have found that bacteria can readily degrade gastropod mucus and that it can act as the basis for biofilm formation. There have also been studies that show unique employment of energy saving strategies by snails that use their trails to capture food items and to reduce production needs by following trails laid by conspecifics. Very little research has been conducted on freshwater gastropods. This study is the first to focus solely on the ecological and functional aspects of freshwater snail mucus. </p><p> For this study, collections of <i>E. potosiensis</i> were made from a single site along the Meramec River to qualify the effect deposited mucus has on the adherence of microalgae and its potential for formation of biofilms. Overall, mucus-coated surfaces significantly more particles in flow than non-coated surfaces. The water velocity at which a trail is laid was not found to have an affect on the thickness, adhesive ability or persistence of a trail. However, the water velocity in which a trail is incubated in stream does have effect on the adherence rate of a trail. In this study, it was found that this was most likely due to the fact that trails in high water velocity come into contact with more particles during a given period of time due, in part, to its higher carrying capacity.</p>

New Caledonian crows (NC crows; Corvus moneduloides) are the most prolific avian tool-users and crafters, using up to three unique tool types derived from numerous plant materials. Since the discovery that wild populations of NC crows use and manufacture different tools in different locations with no measured environmental correlates to these distributions, the process by which NC crows acquire their tool-oriented behavior has been investigated. Two major findings were discovered in 2005: NC crows have a genetic predisposition to manipulate stick like objects, and they increase their rate of manipulation when exposed to social influences. Since then, much of the research into the sociality of wild NC crows has focused on direct social influences, especially the parent-juvenile relationship, yet no social network of wild NC crows has been described. In my thesis, I characterized a new proximity-logging device, Encounternet, and outline a four-step plan to assess error in animal borne devices; uncovered drivers, such as relatedness, space-use, and environmental factors, of wild NC crow sociality, and experimentally manipulated the social network, revealing immediate changes to the number of day-time and roosting partners, the breakdown of first-order relatedness driving sociality, and an increase in the amount of time NC crows associate; and revealed an indirect pathway via tools left behind by conspecifics allowing for the transmission of tool-properties between unrelated NC crows. Altogether, I furthered our understanding of wild NC crow sociality through the use of an animal-borne device, experimental manipulation in the wild measuring the response of the NC crow social network, and demonstrated the utility of animal-borne devices in mapping the network of a population of wild birds.