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Consumers employ a variety of foraging strategies, and oftentimes the foraging strategy employed is related to resource availability. As consumers acquire resources, they may interact with their resource base in mutualistic or antagonistic ways—falling along a mutualism‐antagonism continuum—with implications for ecological processes such as seed dispersal. However, patterns of resource use vary temporally, and textbook herbivores may switch foraging tactics to become more frugivorous in periods of greater fleshy fruit availability. In this study, we investigated how fleshy fruit consumption of a generalist herbivore—the gopher tortoise (Gopherus polyphemus)—shifts intra‐annually following seasonal precipitation and subsequently examined how this shift toward increased frugivory influences the suite of plant syndromes dispersed. We noted a clear intra‐annual shift toward a more frugivorous diet which coincided with seasonal precipitation and subsequently observed a marked shift in the plant syndromes dispersed with increasing frugivory. We found that as this generalist herbivore became more frugivorous, it dispersed a greater variety of plant syndromes at low levels of frugivory. However, when the gopher tortoise exhibited high levels of frugivory, the seed load was dominated by those exhibiting the endozoochory syndrome. This study illustrates a functional shift in a seed‐dispersing herbivore toward that of a classical frugivore, suggesting that temporal variation in foraging strategy and the temporal scale in which foraging habits and seed dispersal interactions are quantified have implications for the suite of plant syndromes species disperse. Furthermore, trade‐offs may exist that provide plants with the endozoochory syndrome with a competitive advantage over seeds with contrasting traits, such as the foliage is the fruit syndrome which is expected to experience greater dispersal by classical herbivores. [ABSTRACT FROM AUTHOR]

Globally, vector‐borne diseases are increasing in distribution and frequency, affecting humans, domestic animals, and wildlife. Science‐based management and prevention of these diseases requires a sound understanding of the distribution and environmental requirements of the vectors and hosts involved in disease transmission. Integrated Species Distribution Models (ISDM) account for diverse data types through hierarchical modeling and represent a significant advancement in species distribution modeling. We assessed the distribution of the soft tick subspecies Ornithodoros turicata americanus. This tick species is a potential vector of African swine fever virus (ASFV), a pathogen responsible for an ongoing global epizootic that threatens agroindustry worldwide. Given the novelty of this method, we compared the results to a conventional Maxent SDM and validated the results through data partitioning. Our input for the model consisted of systematically collected detection data from 591 sampled field sites and 12 historical species records, as well as four variables describing climatic and soil characteristics. We found that a combination of climatic variables describing seasonality and temperature extremes, along with the amount of sand in the soil, determined the predicted intensity of occurrence of this tick species. When projected in geographic space, this distribution model predicted 62% of Florida as suitable habitat for this tick species. The ISDM presented a higher TSS and AUC than the Maxent conventional model, while sensitivity was similar between both models. Our case example shows the utility of ISDMs in disease ecology studies and highlights the broad range of geographic suitability for this important disease vector. These results provide important foundational information to inform future risk assessment work for tick‐borne relapsing fever surveillance and potential ASF introduction and maintenance in the United States. [ABSTRACT FROM AUTHOR]

Human‐mediated animal movement can expose wildlife populations to novel environments. Phenotypic plasticity can buffer against the challenges presented by novel environments, while adaptation to local ecosystems may limit resilience in novel ecosystems. Outbreeding depression during the mixing of disparate gene pools can also reduce reproductive success after long‐distance movement. Here, we use a ‘common‐garden’ population of gopher tortoises (Gopherus polyphemus), translocated from numerous sites across the state of Florida, USA, to a mitigation site in the north‐west (panhandle) region to assess whether geographic origin, outbreeding effects, and behavioral plasticity influence reproductive success in this threatened keystone species. We found that females from north‐east Florida produced clutches with lower hatching success than females from other regions. We detected regional differentiation in nest site selection behavior in the common environment of the translocation site, though these differences did not mediate the regional effect on hatching success. We also found evidence for outbreeding depression: hatching success declined with increasing parental geographic and genetic distances, dropping from 93% to 67% across the range of observed parental genetic distances. Together, these results suggest that newly admixed populations may suffer reproductive costs due to historical population differentiation, and that undetected outbreeding depression could significantly hamper conservation efforts for this species and others undergoing a variety of human‐mediated movements. [ABSTRACT FROM AUTHOR]

Line‐transect distance sampling (LTDS) surveys are commonly used to estimate abundance of animals or objects. In terrestrial LTDS surveys of gopher tortoise (Gopherus polyphemus) burrows, the presence of ground‐level vegetation substantially decreases detection of burrows of all sizes, but no field or analytical methods exist to control for spatially heterogeneous vegetation obstruction as a source of variation in detection. We propose the addition of a simple measurement of ground‐level vegetation that serves as a covariate for the detection function. We present a Bayesian hierarchical model in which covariates burrow width and nearby vegetation height help to account for detection bias and improve precision of estimated density. We investigate the performance of this covariate by simulation and by using real LTDS data collected before and after application of prescribed fire. We collected data in 2018 at the Jones Center at Ichauway in Newton, Georgia, USA. Across all simulations, our model including both covariates produced the most accurate density point estimates of any of the models tested. For our case study, our Bayesian model with vegetation covariates tended to produce similar estimates of density before and after burns. Our study indicates that any level of spatial variation in vegetation obstruction decreases detection of burrows and may lead to underestimation in population size (≤68%) and proportion of individuals with small burrow sizes (≤32%) when not considered during analysis. Our work is extensible to other terrestrial sampling efforts where systematic measurement of a spatially distributed obstructing feature is feasible during the LTDS survey. [ABSTRACT FROM AUTHOR]

Long‐term datasets are required to understand the response of long‐lived organisms (e.g., gopher tortoises [Gopherus polyphemus]) to management actions, such as prescribed burns. Our objective was to estimate the effects of prescribed burning on gopher tortoise population dynamics over decadal time frames at Fort Stewart Army Reserve, southeastern Georgia, USA. We captured and marked adult tortoises from 1994–2020. In addition, since the early 1990s, managers at Fort Stewart collected spatial records of prescribed burns; thus, we could compare demography of the population to prescribed burning. We used a Bayesian hierarchical model (open population Jolly‐Seber model) to estimate population parameters (emigration and survival, immigration and recruitment, and adult abundance) and their relationships with years since burn. We observed opposing responses to years since burn at 2 sites: abundance and the probability of staying (survival plus not emigrating) increased within 1 site when it had been more recently burned (F zones), but abundance and probability of staying in a second site increased when it had been longer since the site was burned (E zones). Some of these effects were weak but indicative of different responses to burning between the sites. Although the sites experienced similar burning regimes, they differed substantially in other habitat features: the F zones had almost twice the tree cover and lower soil sand composition, indicating that tortoise population responses to burning depend on habitat context. We inferred that the primary mechanism for demographic responses to years since burn was likely emigrating adults, which indicates the need for more detailed movement data. Our results demonstrate that gopher tortoise population responses to prescribed burning are complex, context dependent, and primarily influenced by tortoise movements. Therefore, prescribed burn plans may best accommodate spatially dynamic tortoise populations when they create spatial heterogeneity in burn ages within the range of typical tortoise movements. © 2021 The Wildlife Society. Gopher tortoises at 2 sites exhibited opposing population responses to prescribed burning, with differences likely attributable to habitat differences between the 2 sites. Tortoise populations likely responded to burning through increases or decreases in emigration; therefore, prescribed burn plans should be designed to accommodate spatially dynamic tortoise populations, allowing tortoises to select burn ages that are the most beneficial given other habitat conditions. [ABSTRACT FROM AUTHOR]

Gopher tortoises (Gopherus polyphemus) are among the most commonly translocated reptiles. Waif tortoises are animals frequently of unknown origin that have been displaced from the wild and often held in human possession for various reasons and durations. Although there are risks associated with any translocation, waif tortoises are generally excluded from translocation projects because of heightened concerns of introducing pathogens and uncertainty about the post‐release survival of these individuals. If these risks could be managed, waif tortoises could have conservation value because they can provide the needed numbers to stabilize populations. In the early 1990s, the discovery of an isolated population of gopher tortoises (≤15 individuals) near Aiken, South Carolina, USA, prioritized establishment of the Aiken Gopher Tortoise Heritage Preserve (AGTHP). Because of the population's need for augmentation and the site's isolation from other tortoise populations, the AGTHP provided the opportunity to evaluate the post‐release survival of translocated waif tortoises without compromising a viable population. Since 2006, >260 waif tortoises have been introduced to the preserve. Using a Cormack‐Jolly‐Seber modeling framework to analyze release records and capture histories from trapping efforts in 2017 and 2018, we estimated the long‐term apparent survival and site fidelity of this population composed largely of waif tortoises. We estimated annual apparent survival probabilities to be high (≥0.90) for subadult, adult male, and adult female tortoises, and these rates were similar to those reported for wild‐to‐wild translocated gopher tortoises and those from unmanipulated populations. Of the tortoises recaptured within the boundaries of the preserve, 75% were located within 400 m of their release location. These results suggest that waif tortoises could be an important resource in reducing the extirpation risk of isolated populations. © 2021 The Wildlife Society. Released waif gopher tortoises—formerly captive individuals or those of unknown provenance—exhibited high long‐term site fidelity and annual apparent survival rates similar to survival reported for unmanipulated populations and wild‐to‐wild translocated tortoises. Provided that risks can be managed, waif gopher tortoises can contribute to recovery of isolated populations in need of augmentation. [ABSTRACT FROM AUTHOR]

Population manipulations such as translocation and head‐starting are increasingly used as recovery tools for chelonians. But evaluating success of individual projects can require decades of monitoring to detect population trends in these long‐lived species. Furthermore, there are often few benchmarks from stable, unmanipulated populations against which to compare demographic rates, particularly for the immature stages. We used 8 years of mark‐recapture data to estimate apparent survival of immature gopher tortoises (Gopherus polyphemus) recruited into an introduced population of gopher tortoises first established on St. Catherines Island, Georgia, USA, in 1987. During 2006–2013, we conducted targeted trapping of immature gopher tortoises and compared survival of the hatchling, juvenile and subadult stages among treatments: individuals released shortly after hatching from eggs obtained from gravid female founders (direct releases), individuals reared in captivity for 6–9 months following hatching (head‐starts), and individuals first encountered as free‐ranging, wild‐recruited offspring (wild recruits). Among the candidate models we examined, the best fit model included additive effects of tortoise stage and treatment; however, overlapping 95% credible intervals among treatments (CrI) suggested that survival did not vary significantly among treatments. Annual apparent survival increased over the immature period, highlighting the importance of calculating separate estimates for the different immature stages. Across all treatments, the additive model estimated annual apparent survival probability to be 0.37 (CrI = 0.25–0.48) for hatchlings, 0.71 (CrI = 0.61–0.81) for juveniles, and 0.83 (CrI = 0.74–0.94) for subadults. Our study, in combination with previous monitoring efforts at St. Catherines Island, provides strong evidence that the translocation and subsequent population augmentation efforts have been successful in establishing a robust population of gopher tortoises. Additionally, our results provide estimates of demographic rates for life stages that are poorly understood but critical to understanding population dynamics of this imperiled species. © 2020 The Wildlife Society. Eight years of mark‐recapture targeting immature life stages provided survival estimates for hatchling, juvenile, and subadult gopher tortoises recruited following translocation. These results, in combination with other monitoring of the population, provide strong evidence that the translocation and subsequent population augmentation efforts have been successful in establishing a robust population of gopher tortoises. [ABSTRACT FROM AUTHOR]

Gopherus polyphemus populations are diminishing throughout their range due to urbanization, fragmentation, and poor habitat management. Increased population densities, poor habitat quality, and lack of fire may influence disease transmission. Parasite roles within wild tortoise populations are largely unknown; despite evidence these pathogens may pose significant health risks. This study provides a baseline of gopher tortoise intestinal parasites across South Florida and reports on how varying environmental and tortoise characteristics may affect intestinal parasite species prevalence and approximate loads. Tortoise fecal samples were taken from six tortoise populations across five South Florida sites. Seven species of intestinal parasites were discovered from 123 tortoises. Identified parasites include endohelminths such as cyathostomes, pinworms, ascarids, flukes, and protozoans including Eimeria, Cryptosporidium, and Amoeba species. Significant differences in parasite prevalence and loads were seen between sites, while parasitism among sex, size class, and habitat type remained relatively ubiquitous. [ABSTRACT FROM AUTHOR]

ABSTRACT: Gopher tortoise (Gopherus polyphemus) populations are declining throughout their range and recovery requires management intervention to alleviate losses. Population augmentation strategies may prove useful in recovery of depleted populations once threats are mitigated. We head‐started and soft‐released hatchlings produced from robust donor populations and evaluated their post‐release survivorship and movement for the first year following their release. During 2014 and 2015, we head‐started and released 145 tortoises, of which we radio‐tracked a subset of 41 individuals, from 2 cohorts at 2 release areas within Yuchi Wildlife Management Area in Burke County, Georgia, USA. Movement and mortality of gopher tortoises was highest in the first month after release but declined soon after. Estimated annual survivorship of our first cohort was 60.6%. Annual survivorship of our second cohort was low (7.1%) at the southeast release area but much higher (75.0%) at the northwest release area because of spatial variation in predation. Although survivorship was variable, site fidelity remained high throughout the study and no tortoise moved >122.0 m from its release location. Initial results suggest that head‐starting could prove effective as a population recovery tool, but that release strategy and predator mitigation, especially within the first month, are critical to success. © 2018 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Ectotherms frequently thermoregulate behaviorally to improve physiological processes such as digestion and growth, but basking and other thermoregulatory activities can also increase predation risk. Organismal and environmental characteristics can, in some species, influence predation risk associated with thermoregulation and thereby relax or tighten constraints on thermoregulatory behavior, physiological performance, and, ultimately, life history traits. Providing one of the first such investigations in turtles, we examine whether behavior and thermal environment modulate a thermoregulation-predation risk trade-off in juvenile gopher tortoises ( Gopherus polyphemus). Young gopher tortoises experience very high predation pressure, and their declining species faces many challenges, including human-induced increased shading of its environment. We hypothesized that in response to simulated predator approach, basking hatchling and juvenile tortoises would: (i) hide inside burrows; (ii) hide for shorter durations in cooler burrows presumably due to greater constraints on physiological performance; and (iii) spend greater time at the surface following disturbance in cool environments because individuals would need to bask more to maintain preferred body temperatures. Basking tortoises always hid inside burrows when approached and exhibited very long flight initiation distances ( [ABSTRACT FROM AUTHOR]

ABSTRACT Sea-level rise due to climate change is a major threat to coastal ecosystems worldwide. Current management to reduce beach erosion often focuses on protecting human structures and research on effects on wildlife is lacking. Using a combination of hierarchical models and generalized linear models, we evaluated how the gopher tortoise ( Gopherus polyphemus) colonized constructed dunes along coastal scrub at the Merritt Island National Wildlife Refuge, central Florida, USA. Over 2 years, we surveyed tortoise populations along natural dunes and 2 constructed dunes (completed in 2012 and in 2014) and estimated tortoise density each summer and winter. Our models indicated that tortoise density along the 2014 dune was comparable to that of natural dunes ( [ABSTRACT FROM AUTHOR]

Single nucleotide polymorphisms ( SNPs) are replacing microsatellites for population genetic analyses, but it is not apparent how many SNPs are needed or how well SNPs correlate with microsatellites. We used data from the gopher tortoise, Gopherus polyphemus-a species with small populations, to compare SNPs and microsatellites to estimate population genetic parameters. Specifically, we compared one SNP data set (16 tortoises from four populations sequenced at 17 901 SNPs) to two microsatellite data sets, a full data set of 101 tortoises and a partial data set of 16 tortoises previously genotyped at 10 microsatellites. For the full microsatellite data set, observed heterozygosity, expected heterozygosity and FST were correlated between SNPs and microsatellites; however, allelic richness was not. The same was true for the partial microsatellite data set, except that allelic richness, but not observed heterozygosity, was correlated. The number of clusters estimated by structure differed for each data set ( SNPs = 2; partial microsatellite = 3; full microsatellite = 4). Principle component analyses ( PCA) showed four clusters for all data sets. More than 800 SNPs were needed to correlate with allelic richness, observed heterozygosity and expected heterozygosity, but only 100 were needed for FST. The number of SNPs typically obtained from next-generation sequencing ( NGS) far exceeds the number needed to correlate with microsatellite parameter estimates. Our study illustrates that diversity, FST and PCA results from microsatellites can mirror those obtained with SNPs. These results may be generally applicable to small populations, a defining feature of endangered and threatened species, because theory predicts that genetic drift will tend to outweigh selection in small populations. [ABSTRACT FROM AUTHOR]

ABSTRACT Gopher tortoise ( Gopherus polyphemus) populations are declining range-wide primarily because of habitat loss, fragmentation, and degradation, but low recruitment due to nest predation also may be contributing to this decline. The relationship of nest location and nest survival is unknown. Therefore, our objective was to determine whether nest location influenced depredation risk and potential recruitment success. Between 30 May 2013 and 3 September 2014, we constructed and monitored 105 artificial gopher tortoise nests (45 in 2013 and 60 in 2014) with 35 nests at each of 3 classifications of nest sites: within active burrow aprons (i.e., the mound of sand at the burrow entrance), inactive burrow aprons, and open sandy sites. Using the artificial nests, we investigated the influence of nest site classification, distance to road, and prescribed fire frequency (<1 year and 1 year since burn) on gopher tortoise nest survival. Additionally, we monitored 21 natural nests at burrow aprons to assess predation patterns as compared to artificial nests. Seventy-two (57%) of 126 nests were fully depredated during the study, and predation rates at artificial and natural nests were similar. We identified predators at 48 nests using trail cameras; the nine-banded armadillo ( Dasypus novemcinctus) was the primary nest predator (69%). Nests in open sandy areas away from burrows exhibited greater daily survival rates (DSR; 0.991 ± 0.005 SE) compared to nests in burrow aprons (active burrow aprons: 0.967 ± 0.018; inactive burrow aprons: 0.949 ± 0.027). Additionally, nests at locations burned the year of the study had a lower chance of survival (DSR: 0.959 ± 0.022) than nests at locations burned the previous year (DSR: 0.991 ± 0.005). Management practices that maintain open sandy areas (e.g., prescribed fire) away from burrows may increase tortoise nest survival. Fire return intervals of >1 year that are implemented frequently enough to maintain open sandy areas would be beneficial to nesting tortoises. © 2016 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Herbivorous vertebrates rely on complex communities of mutualistic gut bacteria to facilitate the digestion of celluloses and hemicelluloses. Gut microbes are often convergent based on diet and gut morphology across a phylogenetically diverse group of mammals. However, little is known about microbial communities of herbivorous hindgut-fermenting reptiles. Here, we investigate how factors at the individual level might constrain the composition of gut microbes in an obligate herbivorous reptile. Using multiplexed 16S rRNA gene sequencing, we characterized the faecal microbial community of a population of gopher tortoises ( Gopherus polyphemus) and examined how age, genetic diversity, spatial structure and kinship influence differences among individuals. We recovered phylotypes associated with known cellulolytic function, including candidate phylum Termite Group 3, suggesting their importance for gopher tortoise digestion. Although host genetic structure did not explain variation in microbial composition and community structure, we found that fine-scale spatial structure, inbreeding, degree of relatedness and possibly ontogeny shaped patterns of diversity in faecal microbiomes of gopher tortoises. Our findings corroborate widespread convergence of faecal-associated microbes based on gut morphology and diet and demonstrate the role of spatial and demographic structure in driving differentiation of gut microbiota in natural populations. [ABSTRACT FROM AUTHOR]

ABSTRACT Gopher tortoises ( Gopherus polyphemus) are among the most frequently translocated herpetofauna; yet, determining translocation success is difficult because tortoises are slow-growing, long-lived organisms with low reproductive potential. Comparing behavioral traits of translocated individuals with those of sympatric or nearby resident individuals can provide an ecologically relevant baseline to determine if translocated individuals show behavioral traits consistent with those of long-term residents. We used radio telemetry to concurrently monitor 21 translocated and 15 resident gopher tortoises across 2 sites in southern Georgia and compared movement patterns, body weights, and multi-scale habitat selection between treatments. Translocated tortoises moved farther and had larger home ranges than resident tortoises but showed similar patterns of site fidelity. We observed no differences in body weight change between treatments. Patterns of habitat selection were similar between treatments in that tortoises selected structurally open habitats at all scales. Our study suggests that more extensive post-release movements compared to resident individuals may not necessarily lead to lower site fidelity in translocated individuals. We suspect that the presence of structurally suitable habitat within the release area and retaining translocated individuals within a pre-release enclosure for 10 months contributed to high site fidelity. Although comparing translocated and resident individuals can help inform translocation efforts, we caution that using resident individuals from ecological sinks may lead to misleading results. © 2014 The Wildlife Society. [ABSTRACT FROM AUTHOR]

ABSTRACT Recovery or sustainable management of wildlife populations often entails management of habitat on which they depend. In this regard, turtles pose unique conservation challenges because of their life histories. The combination of late maturity, low survival when young, and dependence on high adult survival suggests they may be slow to respond demographically to conventional habitat management. Thus, long-term studies are necessary to understand population dynamics and recovery potential in these species. We used 5-11 years of mark-recapture data from 3 populations to evaluate survivorship, demography, and somatic growth of gopher tortoises ( Gopherus polyphemus). Green Grove and Wade Tract (southwest GA) are ecological reserves with a history of land management compatible with tortoises. In contrast, Conecuh National Forest (south-central AL) is a closed-canopy pine plantation with prior intensive site preparation but where management intervention improved habitat for tortoises during the study. Apparent survival was high for mature tortoises (87-98%) compared to immature tortoises (70-82%). Adults comprised 57-79% of individuals captured, with Green Grove and Wade Tract populations dominated by larger individuals but Conecuh having a more uniform size distribution. The largest adults captured at Conecuh (297 mm maximum carapace length [CL]) were smaller than the largest adults from Green Grove (337 mm CL) or Wade Tract (341 mm CL), although characteristic growth constants from von Bertalanffy models were similar among sites. We suggest these results indicate a recovering population at Conecuh, where habitat conditions for gopher tortoises have improved despite a legacy of intense predation by humans and reduced habitat quality at the inception of this national forest. Further, we recommend using a combination of short-term and long-term monitoring metrics to assess population recovery in such long-lived species. © 2014 The Wildlife Society. [ABSTRACT FROM AUTHOR]

ABSTRACT The federally threatened eastern indigo snake ( Drymarchon couperi), native to the southeastern Coastal Plain of the United States, has experienced population declines caused primarily by habitat loss, degradation, and fragmentation. To examine spatial and habitat use requirements of the species, we radiotracked 32 eastern indigo snakes from 2002 to 2004 on Fort Stewart Military Installation and adjacent private lands in Georgia. We estimated annual and seasonal home ranges and evaluated a priori hypotheses examining morphometric and ecological factors (sex, body size, location) associated with intraspecific differences in home range size. We analyzed habitat use hierarchically by examining use across the study area and within home ranges. Annual home range size varied from 33 ha to 1,528 ha (average minimum convex polygon: [ABSTRACT FROM AUTHOR]

Ecosystem engineers play fundamental ecological roles by modifying habitats in ways that affect a multitude of other species and by creating refugia with novel microclimates. We hypothesize that burrow-creating organisms may facilitate climate change adaptation by providing refugia from extreme and fluctuating temperatures found aboveground. We support this hypothesis by showing that large burrow-dwelling tortoises, Gopherus polyphemus, likely depend upon burrows for thermoregulation. By exploiting the varied thermal conditions within burrows, tortoises avoided lethal temperatures and extreme fluctuations in body temperature, maintained moderate and stable body temperatures on hot days, and maintained relatively warm temperatures overnight. Climate change is predicted to increase maximum air temperatures throughout the geographic range of this species, with impacts most severe in Florida, US, where the range of future conditions could be above that of current maxima. This implies that environmental temperatures will be above lethal thermal limits more often, highlighting the importance of refugia from extreme conditions. Large burrowing animals (e.g. aardvarks, pocket gophers, rabbits, seabirds, tortoises, wombats) are widely distributed globally and could provide similar thermal refugia for countless commensal taxa. Burrows and the animals that create them are in urgent need of conservation, which will help ensure the widespread availability of refugia that offer protection from extreme temperatures under climate change. [ABSTRACT FROM AUTHOR]

Engaging private landowners in conservation activities for imperiled species is critical to maintaining and enhancing biodiversity. Market-based approaches can incentivize conservation behaviors on private lands by shifting the benefit-cost ratio of engaging in activities that result in net conservation benefits for target species. In the United States and elsewhere, voluntary conservation agreements with financial incentives are becoming an increasingly common strategy. While the influence of program design and delivery of voluntary conservation programs is often overlooked, these aspects are critical to achieving the necessary participation to attain landscape-scale outcomes. Using a sample of familyforest landowners in the southeast United States, we show how preferences for participation in a conservation program to protect an at-risk species, the gopher tortoise (Gopherus polyphemus), are related to program structure, delivery, and perceived efficacy. Landowners were most sensitive to programs that are highly controlling, require permanent conservation easements, and put landowners at risk for future regulation. Programs designed with greater levels of compensation and that support landowners' autonomy to make land management decisions can increase participation and increase landowner acceptance of program components that are generally unfavorable, like long-term contracts and permanent easements. There is an inherent trade-off between maximizing participation and maximizing the conservation benefits when designing a conservation incentive program. For conservation programs targeting private lands to achieve landscape-level benefits, they must attract a critical level of participation that creates a connected mosaic of conservation benefits. Yet, programs with attributes that strive to maximize conservation benefits within a single agreement (and reduce risks of failure) are likely to have lower participation, and thus lower landscape benefits. Achieving levels of landowner participation in conservation agreement programs that deliver lasting, landscape-level benefits requires careful attention not only to how the program structure influences potential conservation benefits, but also how it influences landowners and their potential to participate. [ABSTRACT FROM AUTHOR]

Gopher tortoise ( Gopherus polyphemus) populations are declining throughout the Southeast, and high levels of predation on nests and juveniles have been suggested as a potential contributor to this decline. Therefore, we documented gopher tortoise nest success and hatchling survival relative to mammalian predator control. We used 4, large (approx. 40-ha) fenced, predator exclosures to exclude mid-sized mammalian predators: bobcat ( Lynx rufus), raccoon ( Procyon lotor), Virginia opossum ( Didelphis virginianus), fox ( Urocyon cinereoargenteus and Vulpes vulpes), coyote ( Canis latrans), nine-banded armadillo ( Dasypus novemcinctus), and skunk ( Mephitis mephitis); 4 unfenced plots served as controls. We monitored nests for survival through hatching and used radio-telemetry to examine hatchling survival. We radio-tracked 40 hatchlings for up to 329 days, but we were only able to track 8 individuals from a single nest at an unfenced plot because of high nest predation. Mean nest survival was greater at exclosures than at unfenced controls ( F1, 2 = 45.80, P = 0.0001). Hatchling survival differed ( χ2 = 5.839, P = 0.016) between unfenced plots (37.5%) and exclosures (74.4%), suggesting that mammals also were significant predators of hatchlings. The number of juvenile (<13 cm in diameter) and subadult tortoise burrows (13-21.9 cm) increased over a 6-year period in exclosures, providing further support for an effect of excluding mammalian predators on nest and juvenile tortoise survival. © 2012 The Wildlife Society. [ABSTRACT FROM AUTHOR]

The progressive loss and fragmentation of longleaf pine forests throughout the southeastern United States has led to severe declines in habitat specialists such as the federally listed gopher tortoise Gopherus polyphemus. However, little is known of the range-wide historical genetic structure of this species or how habitat loss may have impacted the genetic diversity of this species over time. As genetic data are lacking in many parts of the gopher tortoise range, management of federally listed populations in Louisiana and Mississippi have been based on conservation units delineated by rivers. However, this current management strategy has been formulated without any knowledge of how riverine barriers might relate to genetic population structure. Here, we examine variability of mitochondrial and nuclear microsatellite markers in gopher tortoise populations across their natural range in the southeastern United States. Results from the mitochondrial data showed a historical phylogenetic break that is coincident with the Apalachicola River and a novel population assemblage located within western Georgia. Genetic structure based on microsatellite loci revealed high levels of genetic differentiation in some regions and a pattern of isolation by distance at two spatial scales. We also find that rivers across the federally listed portion of the range, do not significantly influence gene flow. Coalescent analyses of population demographic change in gopher tortoises indicate evidence of an ancient and severe population decline at sites across the range. Findings from this study provide important information that will aid in the identification of distinct population units for management and in the formulation of recommendations for the future maintenance of genetic diversity in this species. [ABSTRACT FROM AUTHOR]

Despite a heightened interest regarding the role of infectious diseases in wildlife conservation, few studies have explicitly addressed the impacts of chronic, persistent diseases on long-term host population dynamics. Using mycoplasmal upper respiratory tract disease (URTD) within natural gopher tortoise Gopherus polyphemus populations as a model system, we investigated the influence of chronic recurring disease epizootics on host population dynamics and persistence using matrix population models and Markov chain models for temporally autocorrelated environments. By treating epizootics as a form of environmental stochasticity, we evaluated host population dynamics across varying levels of outbreak duration (ρ), outbreak recurrence ( f), and disease-induced mortality (μ). Baseline results indicated a declining growth rate (λ) for populations under unexposed or enzootic conditions (λEnzootic= 0.903, 95% CI: 0.765-1.04), and a median time to quasi-extinction of 29 years (range: 28-30 years). Under recurring epizootics, stochastic growth rates overlapped with baseline growth rates, and ranged between 0.838-0.902. Median quasi-extinction times under recurring epizootics also overlapped for most scenarios with those of baseline conditions, and ranged between 18-29 years, with both metrics decreasing as a function of f and μ. Overall, baseline (enzootic) conditions had a greater impact on λ than epizootic conditions, and demographic vital rates were proportionately more influential on λ than disease- or outbreak-associated parameters. Lower-level elasticities revealed that, among disease- and outbreak-associated parameters, increases in μ, force of infection (φ), and f negatively influenced λ. The impact of disease on host population dynamics depended primarily on how often a population underwent an epizootic state, rather than how long the epizootic persisted within the exposed population. The modeling framework presented in this paper could be widely applied to a range of wildlife disease systems in which hosts suffer from persistent recurring diseases. [ABSTRACT FROM AUTHOR]

Status and trends of gopher tortoise (Gopherus polyphemus) populations are a critical information need for natural resource managers, researchers, and policy makers. Many tortoise populations are small and isolated, which can present challenges for deriving population estimates. Our objective was to compare abundance and density estimates for a small tortoise population derived using a total burrow count versus estimates obtained with line transect distance sampling (LTDS) using repeated surveys. We also compared results of the 2 survey methods using standard burrow-to-tortoise correction factors versus assessing occupancy of all burrows with a camera scope. In addition, we compared LTDS data obtained using a compass and measuring tape to define transects to those obtained using a Global Positioning System (GPS) and Personal Data Assistant (PDA) field computer to navigate transects. Line transect distance sampling with repeated surveys (both with a measuring tape and compass and with a GPS-PDA) yielded sufficient observations of tortoises to calculate population estimates. From 18% to 31% of burrows were occupied by tortoises as determined with the burrow camera. We found 25 burrows during the LTDS survey that we did not find in the total count survey, which demonstrated that the assumption of 100% detection for the total count was not met; hence, density or abundance measurements derived with this method were underestimates. We recommend using GPS-PDA technology, scoping all burrows detected, and using LTDS with repeated surveys to estimate abundance and density for small gopher tortoise populations. [ABSTRACT FROM AUTHOR]

The article provides information on the force of infection issue of the upper respiratory tract disease (URTD) and its impact to the gopher tortoises' survivability. It mentions the morbid impact of the URTD to the population of wild animals, particularly the gopher tortoises. Researchers have determined that the force of infection and its impact to these creatures remained uncertain. In addition, the researchers have found out that the seropositivity of these tortoises have higher chance to survive from the URTD compared to the tortoise with no seropositivity.

As gopher tortoises (Gopherus polyphemus) increasingly become threatened throughout their range in Florida, USA, the need for management and conservation will intensify. Here we evaluate the forensic applicability of genetic assignment tests based on microsatellite genotypic data to 1) accurately assign individuals in our genetic database to the sample location or population of origin and 2) determine the origin of 6 confiscated tortoises. Overall, we could correctly assign 90% of the individuals in the database to their population of origin, but we were unable to determine the source of the confiscated tortoises. However, these individuals are unlikely to have come from any of our sampled sites and all 6 may have come from the same population. This approach can be used by law enforcement personnel to identify the origin of confiscated tortoises as well as by developers and wildlife managers to determine the genetic appropriateness of potential recipient populations when it is necessary to relocate individuals. [ABSTRACT FROM AUTHOR]

Relocations of gopher tortoises (Gopherus polyphemus) in Florida, USA, are frequently employed as mitigation tools when tortoises occupy land desired for development. Here we present information about retention and health of a relocated population of gopher tortoises 17 years after relocation. We combine our 17-year postrelocation data with earlier surveys 1 year and 2 years postrelocation to examine whether retention rates change over time. We also evaluate whether retention rates vary by age and gender. Of 74 gopher tortoises relocated in 1985, 31 were present in 2002. We found a 1-year retention rate of 42%, with retention rates of 100% each year thereafter, when we used the percentage of relocated individuals captured at each survey. We found a 1-year retention rate of 73%, a retention rate of 92% from year 1 to year 2, and an overall retention rate of 98.5% from year 2 through year 17, based on the assumption that all individuals present in later surveys were present in earlier surveys. We found no significant difference in retention rate over the 17-year period for adults and juveniles and for adult males and females. Relocated gopher tortoises showed natural growth patterns, indicating good health, but 35% of these gopher tortoises had ≥1 symptom of upper respiratory tract disease, a disease associated elsewhere with population declines of tortoises. Thus, retention rates of relocated gopher tortoises change over time, with relatively low retention during the first year postrelocation but nearly 100% retention in subsequent years. In general, our study shows that relocations can successfully lead to long-term retention of gopher tortoises, but we predict that without management (e.g., fire management and predator control) this relocated population is not viable. [ABSTRACT FROM AUTHOR]

Minimum patch size for a viable population can be estimated in several ways. The density—area method estimates minimum patch size as the smallest area in which no new individuals are encountered as one extends the arbitrary boundaries of a study area outward. The density—area method eliminates the assumption of no variation in density with size of habitat area that accompanies other methods, but it is untested in situations in which habitat loss has confined populations to small areas. We used a variant of the density—area method to study the minimum patch size for the gopher tortoise (Gopherus polyphemus) in Florida, USA, where this keystone species is being confined to ever smaller habitat fragments. The variant was based on the premise that individuals within populations are likely to occur at unusually high densities when confined to small areas, and it estimated minimum patch size as the smallest area beyond which density plateaus. The data for our study came from detailed surveys of 38 populations of the tortoise. For all 38 populations, the areas occupied were determined empirically, and for 19 of them, duplicate surveys were undertaken about a decade apart. We found that a consistent inverse density—area relationship was present over smaller areas. The minimum patch size estimated from the density-area relationship was at least 100 ha, which is substantially larger than previous estimates. The relative abundance of juveniles was inversely related to population density for sites with relatively poor habitat quality, indicating that the estimated minimum patch size could represent an extinction threshold. We concluded that a negative density—area relationship may be an inevitable consequence of excessive habitat loss. We also concluded that any detrimental effects of an inverse density—area relationship may be exacerbated by the deterioration in habitat quality that often accompanies habitat loss. Finally, we concluded that the value of any estimate of minimum patch size as a conservation tool is compromised by excessive habitat loss. [ABSTRACT FROM AUTHOR]

As quality of forested habitat declines from altered fire regimes, gopher tortoises (Gopherus polyphemus) often move into ruderal areas to the detriment of the animal and land manager. We evaluated effects of a dormant-and-growing-season prescribed fire on habitat and gopher tortoise use of degraded longleaf pine (Pinus palustris) forests surrounding military training areas. We burned 4 of 8 sites in winter 2001-2002 and again in April 2003. Changes in vegetation measured during 2001-2004 indicated that burn treatments did not increase herbaceous vegetation. Similarly, movement patterns, burrow usage, and home range of tortoises radiotracked from 2002-2004 did not differ between treatments. Woody cover initially was reduced in the forests postburn, and we found more new burrows in burned forest sites. Once shrub cover was reduced, tortoises started using forested habitat that had become overgrown. However, shrub reduction may be temporary, as woody stem densities increased postburn. Thus, the one-time use of fire to manage tortoise habitat may not rapidly restore the open canopy, sparse woody midstory, and abundant herbaceous vegetation that this species requires. Repeated prescribed fires or additional management techniques may be needed for complete restoration. [ABSTRACT FROM AUTHOR]

Focuses on the efforts of the Florida Fish and Wildlife Conservation Commission to identify the vulnerability of red-cockaded woodpecker and gopher tortoise for the purpose of conservation and management. Factors that influence conservation and management alerts based on population trends; Reclassification of red-cockaded woodpecker and gopher tortoise; Importance of analyzing the ecological role of species in evaluating conservation alerts.

The western population of the gopher tortoise (Copherus polyphemus) was listed as threatened under the Endangered Species Act in 1987 due to extensive population declines. Declines have been linked to site conversion of native pine (Pinus spp.) forests for urban development, agriculture, and commercial forest management. We conducted surveys to detect tortoise burrows on corporate timberlands in southern Mississippi and southwestern Alabama during summer 1994. We surveyed 2,759 0.5-ha strip transects on soil types of 9 different suitability categories for gopher tortoises. We found 460 active and 264 abandoned burrows on the 1,380 ha surveyed. Edaphic and vegetative conditions, such as sandy soils and total and midstory canopy coverage, influenced gopher tortoise occurrence. Logistic regression analyses revealed that active burrow occurrence was related positively to deep, sandy soils and related negatively to total canopy closure and fine loam soils with limited sand content. Abandoned burrow occurrence was related positively to increasing midstory canopy closure and selected soil types. Sandy soils and open overstory canopy that created favorable burrowing, nesting, and foraging conditions were important influences in active burrow occurrence. Vegetation management techniques, such as prescribed fire, midstory control, and intermediate forest stand thinning, are recommended on gopher tortoise conservation areas and connective corridor habitats on commercial timberlands. We theorize that restoration of longleaf pine (P. palustris) forests on sandy ridges can produce desirable core habitats and dispersal corridors for gopher tortoises in landscapes dominated by intensively managed pine plantations. [ABSTRACT FROM AUTHOR]

Presents a study that examined a method for monitoring gopher tortoise burrows in Eglin Air Force Base, Florida. Use of infrared triggers for monitoring temporal activity data on gopher tortoises and commensal species; Remote monitoring results on mammals; Advantages of using the monitoring technique for animal activities.

Presents information on a study which investigated burrow dynamics and the factors associated with the abandonment of burrows by gopher tortoises in slash pine plantations of the Conecuh National Forests in Alabama. Study area; Methods used; Results and discussion; Management implications.

The slow rate of mtDNA evolution in turtles poses a limitation on the levels of intraspecific variation detectable by conventional restriction fragment surveys. We examined mtDNA variation in the gopher tortoise (Gopherus polyphemus) using an alternative restriction assay, one in which PCR-amplified segments of the mitochondrial genome were digested with tetranucleotide-site endonucleases. Restriction fragment polymorphism representing four amplified regions were analysed to evaluate population genetic structure among 112 tortoises throughout the species' range. Thirty-six haplotypes were identified, and three major geographical assemblages (Eastern, Western, and Mid-Florida) were resolved by UPGMA and parsimony analyses. Eastern and Western assemblages abut near the Apalachicola drainage, whereas the Mid-Florida assemblage appears restricted to the Brooksville Ridge. The Eastern/Western assemblage boundary is remarkably congruent with phylogeographic profiles for eight additional species from the southeastern U.S., representing both freshwater and terrestrial realms. [ABSTRACT FROM AUTHOR]

1. Light microscopical histological and histochemical methods were used to examine the epidermis of the Gopher tortoise Testudo polyphemus. 2. The living germinative epidermis did not develop a granular layer and it was only a few cells in depth but the overlying stratum corneum was about twenty cells deep. The mature keratinized cells were extremely flattened and solid in structure but all nuclear basophilic staining was lost. The small horny scales in the neck skin were intermediate in appearance between the loose hinge horny layer and the larger compact scales of the legs. In the narrow hinge regions between the leg scales and also in the wider hinge zones in the neck epidermis, the stratum corneum was made up of layer upon layer of loosely arranged, separate keratinized lamellae. These were formed of horny cells joined at their lateral edges but free on their upper and lower surfaces. 3, The loose hinge horny layer contained some cystine but there was a much stronger reaction in the leg horny scales. Cysteine showed a reversed distribution with a greater concentration in the lunge horny layer and little in tile leg scales. 4. Protein-bound phospholipids were found in the epidermis and were also strongly present in the hinge horny layer and in the neck scales, but the compact leg scales showed only a very weak reaction. There was a similar distribution of protein-bound calcium in the stratum corneum. Nucleic acids were not found in the keratinized cells. 5. Growth rings showed sites of retention in the stratum corneum of old horny cells of previous years. These occurred on the leg scales as well as on the carapace. 6. The stratum corneum of the tortoise appears similar in structure throughout its depth in contrast to the Squamata where differences occur through the thickness of the horny layer. These differences are discussed in relation to keratinization and sloughing. It is suggested that the tortoise horny layer is more homogeneous than in snakes and lizards because keratinization is probably a continuous process in contrast to the cycles of the Squarnata. [ABSTRACT FROM AUTHOR]