<p> The bog turtle (<i>Glyptemys muhlenbergii</i>) is listed as threatened under the U.S. Endangered Species Act primarily because of the loss and degradation of its specialized wetland habitat. Adequate nesting habitat may be a limiting factor for bog turtle recovery, and nesting habitat creation or expansion may be an effective conservation tool but only if managers understand nesting behaviors, habitat requirements, and threats to nest success. The objective of this study was to understand the nesting ecology of the bog turtle and to use this information to suggest improvements to bog turtle management. I used radio telemetry to locate nesting females. I then used nest location and maternal genetic microsatellite data to investigate nest-site fidelity and natal homing. I collected microhabitat data at each nest and random points in both spring and fall at three spatial scales to understand nest-site selection. I also studied nest success with and without predator excluder cages to determine if predator excluders reduced predation or altered nest conditions. I found evidence that females display nest-site fidelity to nest-site areas but no evidence for natal homing. Bog turtles nested in relatively small patches of habitat in close proximity to water or saturated soil with low densities of woody stems and low percent cover of woody vegetation, forbs, and ferns. Predator excluders reduced predation by &sim;40% while having no effect on nest temperatures, incubation periods, or underlying (disregarding predation) nest success. Given the results of this research, I conclude that the creation of new nesting areas could be a viable conservation tool, as females do not always return to the same nest-site area. Managers should create or maintain small patches of open-canopy habitat with reduced woody vegetation in areas that have consistent moisture from spring to fall. Increasing the availability of nesting areas may eventually lead to increases in recruitment, but if predation pressures are high, managers should also deploy predator excluders. This is the first study to examine the behavioral drivers of bog turtle nest-site selection and the efficacy of predator excluders on bog turtle nests.</p>

<p> Effective conservation strategies for imperiled species require an understanding of processes that influence fitness throughout the organism's life cycle and across the range of habitats needed to complete that cycle. I evaluated factors that affect population viability of bull trout <i>Salvelinus confluentus, </i> a threatened freshwater char species, throughout individual life stages and over the entire life cycle. </p><p> I assessed the relationship between bull trout egg incubation success and environmental variables. Egg survival was negatively related to the percent of fine sediment in redds and positively related to hydraulic conductivity and the strength of downwelling. Next, I quantified juvenile bull trout survival rates and described movement patterns for this life stage. Juvenile bull trout emigrated from natal headwaters into larger rivers throughout the entire year and across a range of sizes. Estimates of juvenile survival rates improved dramatically when emigration was incorporated into the analysis. </p><p> I integrated my observations of bull trout survival, growth, and movement to create a life-cycle model, which I used to better understand how populations respond to changes in specific demographic rates. Bull trout populations were particularly sensitive to changes in juvenile growth and survival. The relative effect of changes to fertility rates and adult survival varied depending upon whether a population was composed primarily of large, migratory, or smaller, resident individuals. Dispersal helped to lower the probability of extinction for small or declining populations when neighboring populations were stable. </p><p> My research demonstrates that bull trout require access to habitats throughout entire watersheds to maintain population viability. My results suggest that limiting anthropogenic sources of fine sediment and maintaining areas of channel complexity that promote downwelling can be important for bull trout embryo survival. Management decisions should also consider the diverse behavior of juvenile bull trout and the wide range of habitat they use. Additionally, connectivity between populations is likely to be important for declining populations to persist. The diversity of life-history strategies expressed by bull trout helps maintain demographic stability within and among populations. As such, preservation of habitat integrity and full life-history diversity is imperative for conservation and recovery of bull trout populations range-wide.</p>

<p> South Florida's loggerhead (<i>Caretta caretta</i>), green (<i>Chelonia mydas</i>) and leatherback (<i>Dermochelys coriacea </i>) sea turtles hatchling have environmentally determined sex. The <i> in situ</i> nest mean hatchling sex ratios (SR) were highly femalebiased: loggerhead <i>F</i>=0.89) and green turtle <i>F</i>=0.81; leatherback's SR was nearly balanced (0.55<i>F</i>). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were estimated within biological limitations by both 50-65% of incubation and mean middle 1/3 temperature. The maximum middle 1/3 temperature was the best-fit predictor for green turtles. No best-fit sex ratio-temperature response could be identified for leatherbacks. Clutches incubating under natural conditions can vary greatly in SR; TRT differences may account for differences among species' sex ratios.</p>

<p>The translocation of organisms is becoming a frequently used tool in conservation biology. There are, however, a disproportionate number of unsuccessful attempts translocating populations of herpetofauna. Logistical and temporal limits of monitoring, combined with ambiguous metrics concerning &ldquo;success,&rdquo; have led to few advances regarding reptile translocations. Successfully established and persistent populations are those in which both the founding population and subsequent generations show consistent or positive levels of survival and reproduction. A small population of the threatened Florida Sand Skink (<i>Plestiodon reynoldsi</i>) was translocated in 2007. Data collected from 2007 to 2009 confirmed survival and reproduction among the founding individuals, but the sampling did not include a long enough period to allow for the evaluation of the survival and reproduction of individuals born on the site. In this study, individuals were collected during two separate sampling events, one during the third spring and one during the sixth spring after the translocation occurred. Survival estimates, reproduction, population size and generation structure were calculated by combining and analyzing data from all years post-translocation. The numbers of both total and new individuals captured in the sixth year exceeded captures from every prior sampling event since monitoring began in 2008. Founding individuals represented only 14% of the total individuals captured, while the number of individuals born on site continued to increase. The proportion of recruits and increased number of hatchlings despite the loss of founders shows that the filial generations are producing offspring. The methods utilized in assessing this translocation effort will further the understanding of the population dynamics of the Florida Sand Skink and allow for more informed decisions in future management studies of this threatened species. </p>

<p> Increased agriculture and urbanization in southwestern Illinois have severely fragmented the forests of the region. Habitat fragmentation may cause lower species richness, population declines, or extirpation due to phenomena such as edge effects, inbreeding depression, and stochasticity. The effects of habitat fragmentation on suburban wildlife are poorly understood, especially for small mammals such as the Southern Flying Squirrel (<i>Glaucomys volans</i>). Flying squirrels are arboreal rodents whose presence in a forest is indicative of habitat quality, as this species prefers mature and relatively open forest stands. Flying squirrels can be found in the forested areas of the Southern Illinois University Edwardsville (SIUE) campus. Demographic features of this population and habitat use among forest patches were unknown. Artificial nest boxes were utilized to perform a mark-recapture study of the flying squirrel population as well as examine habitat use. Objectives were to obtain demographic information, and to create a predictive habitat model relating habitat characteristics to presence or absence of nest box materials using logistic regression. Study sites consisted of 145 randomized plots in three forest patches located within the SIUE campus, which were monitored November 2013 through October 2014. A model was generated for combined activity (nesting or feeding materials were present) at plots, which contained forest age, dominance of hard mast at a plot, tree density, topographic position, richness of the shrub layer, and the 90th percentile diameter at breast height. Habitat models were also generated for specified response variables of feeding material presence and nesting material presence. The top model for predicting feeding material presence in a nest box contained dominance of hard mast on a plot, richness of the shrub layer, and basal area of logs. The top model for predicting nesting material presence in a nest box contained the shrub layer stem count, roughness of the nest box tree bark, proximity to edge, cavity count, and the average hard mast dominance in the area surrounding the plot. Models tended to include characteristics regarding hard mast dominance and refugia, suggesting nest box use was influenced by avoidance of predation and food resource availability.</p>

<p> Knowledge of species distribution and habitat associations are essential for conservation measures. Such information is lacking for many marine species due to their occupancy of broad and ephemeral habitats that are difficult to access for study. Sea turtles, specifically the surface&minus;pelagic juvenile stage of some species, are a group for which significant knowledge gaps remain surrounding their distribution and habitat use. Recent research has confirmed the long&minus;standing hypothesis that the surface&minus;pelagic juvenile stage occurs within surface&minus;pelagic drift communities (SPDC). Within the North Atlantic and surrounding basins, the holopelagic macroalgae <i> Sargassum</i> spp. dominates SPDC and serves as a remotely&minus;detectable indicator of SPDC. The present study focuses on surface&minus;pelagic habitats of four sea turtle species and addresses knowledge gaps using two approaches: habitat mapping and behavioral examination. Remote sensing techniques were used to identify SPDC, and satellite telemetry to examine behavior. This work was conducted in three parts and is presented in three chapters. </p><p> Imagery collected from the Landsat satellites (5 and 7) was used to quantify the area of SPDC (km²). Approximately 1,800 Landsat images collected from 2003&ndash;2011 were examined for SPDC. The first chapter discusses the abundance, seasonality, and distribution of SPDC within the eastern Gulf of Mexico waters where surface&minus;pelagic green, hawksbill, Kemp&rsquo;s ridley, and loggerhead turtles are known to occur. SPDC was found year&minus;round within the eastern Gulf of Mexico, and the amount of habitat peaked during summer months. The amount of SPDC within the eastern Gulf of Mexico varied annually with peaks in 2005, 2009, and 2011. High concentrations of SPDC were discovered within offshore waters of the northeastern Gulf of Mexico and southern West Florida Shelf. </p><p> Within the second chapter, the behavior of 10 surface&minus;pelagic juvenile Kemp&rsquo;s ridleys was examined using satellite telemetry. Using remotely&minus;sensed imagery, the sea surface habitats used by tracked turtles were examined. Surface&minus;pelagic juveniles are hypothesized to be principally passive drifters. The behavior of tracked turtles was examined to determine if they exhibited periods of active and passive behavior, which may indicate periods of swim and drift. The proximity of tracked turtles to remotely&minus;detected SPDC was examined when coincident Landsat imagery was available (within one day of the turtle&rsquo;s position). Turtles were tracked for 36.5 days (mean) and exhibited primarily passive behavior during the tracking period. The satellite transmitters messaged frequently and reported temperatures significantly higher than sea surface temperatures. Landsat imagery was available coincident to the tracks of nine individuals. SPDC was present within 74% of images, and the mean distance between tracked turtles and SPDC was 54 km. Close associations between tracked turtles and SPDC were documented for four individuals. Results suggest that the tracked turtles spent a majority of the time drifting within SPDC. </p><p> The final chapter discusses the density of SPDC within northern and western Gulf of Mexico waters from 2009&ndash;2011. Seasonal abundance peaks occurred throughout the study area, but the timing varied. SPDC peaked earlier (late spring) within the northwestern Gulf of Mexico. Moving eastward, the timing of seasonal peaks shifted progressively later during the year. Within the western portions of the study area, SPDC was found to be significantly higher than in the eastern Gulf of Mexico. </p><p> The eastern Gulf of Mexico may provide critical developmental habitats for several North Atlantic sea turtle species. Additional study is necessary to determine if portions of the western Gulf of Mexico could serve in a similar capacity. SPDC is extremely vulnerable to anthropogenic impacts, specifically oil spills and the occurrence of persistent marine debris. Conservation of SPDC may be challenged by its ephemeral nature; however, the results presented herein could advise conservation efforts (e.g., delineation of critical habitat). The present study described spatial patterns of SPDC occurrence, regions of high abundance, and seasonality. The description of the behavior surface&minus;pelagic sea turtles offers refinements to the spatial distribution of this life stage. These results, coupled with information on circulation patterns and the distribution of sea turtle nesting beaches, can be used to better predict when and where sea turtles and SPDC may be found. For example, the year&minus;round persistence of SPDC within the eastern Gulf of Mexico and the location of major nesting beaches located upstream support the area&rsquo;s designation as critical habitat for surface&minus;pelagic green, hawksbill, Kemp&rsquo;s ridley, and loggerhead turtles.</p>

<p> Reliable estimates of species abundance, distribution, and population trajectories are critical in conservation and management. However, for many tropical species that information is missing. We conducted Sharp-shinned Hawk (SSHA) searches during the breeding seasons of 2013, 2014, and 2016 in eight montane forest reserves and their adjacent private lands of Puerto Rico. Further, we developed a maximum entropy model (MaxEnt) of the SSHA&rsquo;s potential distribution using the following environmental variables: aspect, canopy closure, elevation, rainfall, slope, and terrain roughness. Elevation accounted for 89.8% of model fit, predicting the greatest probability of occurrence (> 60%) at elevations above 900 m. The model estimated 0.6%Puerto Rico (56.1 km²) has the greatest probability of occurrence. We developed a periodic population matrix model to describe the influence of early life stages on population growth of the Red-tailed Hawk (RTHA) in eastern Puerto Rico. Our results suggest that the RTHA population has an average annual population increase of 5%, with rates differing between highlands (&lambda;_h = 1.05) and 27% lowlands (&lambda;_l = 1.27). Adult survival was the most important population growth parameter, with more effect in highlands (elasticity = 0.86) than in lowlands (elasticity = 0.53). Sensitivity of &lambda; to changes in nestling survival was greater than for other life-stages (sensitivity lowlands = 0.46, sensitivity highlands = 0.48). I developed an open population N-mixture model to estimate abundance, availability, and detection probability of RTHA in the Luquillo Mountains and western Cordillera Central. The abundance estimates were 0.05 RTHA/ha, with an availability of (&phis;) = ~1 RTHA/per survey point and a detection probability (r) = ~0.25. In Luquillo Mountains, abundance was positively influenced by slope and elevation. In the western Cordillera Central, abundance of RTHA was constant across elevation, slope, and canopy closure. Detection probability decreased with increasing slope and wind conditions and showed a gradual small negative decrease with slope with reduced winds conditions. My findings are a contribution to our knowledge of how population traits and ecological constraints imposed by insular environments are influencing distribution, abundance, and population dynamics of raptors to propose management or conservation schemes.</p><p>

<p> Conservationists have detailed the potential impacts of the Border Wall on wildlife. The issue with this assertion is that little direct measurements of such impacts have been actually made. To determine the current state of the Wall&rsquo;s impacts, if any, I have used phenomenology to ascertain the structure and apparent impacts of the Wall. My measurements of the elements of the Wall&rsquo;s security footprint seem to indicate a potential for impacting wildlife and their habitats, especially if it is to be expanded beyond its current deployment. What I did discover is the full human impacts of the Wall, and these may supersede wildlife impacts and render conservation efforts moot. Conservation of wildlife will need to address the human ecology of the Wall in order to build truly sustainable successes in preservation and restoration projects.</p><p>

abstract: Small-scale fisheries are globally ubiquitous, employing more than 99% of the world’s fishers and providing over half of the world’s seafood. However, small-scale fisheries face many management challenges including declining catches, inadequate resources and infrastructure, and overcapacity. Baja California Sur, Mexico (BCS) is a region with diverse small-scale fisheries; these fisheries are intense, poorly regulated, and overlap with foraging hot spots of endangered sea turtles. In partnership with researchers, fishers, managers, and practitioners from Mexico and the United States, I documented bycatch rates of loggerhead turtles at BCS that represent the highest known megafauna bycatch rates worldwide. Concurrently, I conducted a literature review that determined gear modifications were generally more successful than other commonly used fisheries management strategies for mitigating bycatch of vulnerable megafauna including seabirds, marine mammals, and sea turtles. I then applied these results by partnering with researchers, local fishers, and Mexico’s federal fisheries science agency to develop and test two gear modifications (i.e. buoyless and illuminated nets) in operating net fisheries at BCS as potential solutions to reduce bycatch of endangered sea turtles, improve fisheries sustainability, and maintain fisher livelihoods. I found that buoyless nets significantly reduced mean turtle bycatch rates by 68% while maintaining target catch rates and composition. By contrast, illuminated nets did not significantly reduce turtle bycatch rates across day-night periods, although they reduced mean turtle bycatch rates by 50% at night. Illuminated nets, however, significantly reduced mean rates of total bycatch biomass by 34% across day-night periods while maintaining target fish catch and market value. I conclude with a policy analysis of the unilateral identification of Mexico by the U.S. State Department under section 610 of the Magnusson-Stevens Fishery Conservation and Management Act for failure to manage bycatch of loggerhead turtles at BCS. Taken together, the gear modifications developed and tested here represent promising bycatch mitigation solutions with strong potential for commercial adoption, but fleet-wide conversion to more selective and turtle-friendly gear (e.g. hook and line and/or traps) at BCS, coupled with coordinated international conservation action, is ultimately needed to eliminate sea turtle bycatch and further improve fisheries sustainability. / Dissertation/Thesis / Doctoral Dissertation Biology 2015

<p> Coral reefs on Florida&rsquo;s Reef Tract (FRT) are susceptible to many anthropogenic influences including controlled freshwater discharges and agricultural runoff as well as high natural environmental variability from seasonal rainfall, runoff and upwelling. To better understand coral population structure and responses to sublethal stressors, populations of the scleractinian coral <i> Montastraea cavernosa</i> in the northern FRT were examined using a combination of genomic and transcriptomic techniques. Microsatellite genetic markers identified high local retention among sites and a slight southward gene flow. An _in-situ temporal gene expression analysis utilizing a tag-based sequencing transcriptomic approach was used to analyze baseline coral health at St. Lucie Reef (SLR), off Stuart, FL. Temporal variation had the greatest influence of differential gene expression among <i>M. cavernosa</i> at SLR. Results will be shared with local resource managers and coupled with a complementary <i> ex-situ</i> experimental trial.</p><p>