Concurrent threats and extinction risk in a long-lived, highly fecund vertebrate with parental care

Detecting declines and quantifying extinction risk of long-lived, highly fecund vertebrates, including fishes, reptiles, and amphibians, can be challenging. In addition to the false notion that large clutches always buffer against population declines, the imperiled status of long-lived species can often be masked by extinction debt, wherein adults persist on the landscape for several years after populations cease to be viable. Here we develop a demographic model for the eastern hellbender (Cryptobranchus alleganiensis), an imperiled aquatic salamander with paternal care. We examined the individual and interactive effects of three of the leading threats hypothesized to contribute to the species' demise: habitat loss due to siltation, high rates of nest failure, and excess adult mortality caused by fishing and harvest. We parameterized the model using data on their life history and reproductive ecology to model the fates of individual nests and address multiple sources of density-dependent mortality under both deterministic and stochastic environmental conditions. Our model suggests that high rates of nest failure observed in the field are sufficient to drive hellbender populations toward a geriatric age distribution and eventually to localized extinction but that this process takes decades. Moreover, the combination of limited nest site availability due to siltation, nest failure, and stochastic adult mortality can interact to increase the likelihood and pace of extinction, which was particularly evident under stochastic scenarios. Density dependence in larval survival and recruitment can severely hamper a population's ability to recover from declines. Our model helps to identify tipping points beyond which extinction becomes certain and management interventions become necessary. Our approach can be generalized to understand the interactive effects of various threats to the extinction risk of other long-lived vertebrates. As we face unprecedented rates of environmental change, holistic approaches incorporating multiple concurrent threats and their impacts on different aspects of life history will be necessary to proactively conserve long-lived species.

The habitat quality paradox: loss of riparian forest cover leads to decreased risk of parasitism and improved body condition in an imperiled amphibian

Amphibian declines are a global phenomenon but responses of populations to specific threats are often context dependent and mediated by individual physiological condition. Habitat degradation due to reduced riparian forest cover and parasitism are two threats facing the hellbender salamander (Cryptobranchus alleganiensis), but their potential to interact in nature remains largely unexplored. We investigated associations between forest cover, parasitic infection and physiology of hellbenders to test the hypotheses that physiological condition responds to infection and/or habitat degradation. We sampled 17 stream reaches in southwest Virginia, USA, on a year-round basis from 2013 to 2016 and recorded 841 captures of 405 unique hellbenders. At each capture we documented prevalence of two blood-associated parasites (a leech and trypanosome) and quantified up to three physiological condition indices (body condition, hematocrit, white blood cell [WBC] differentials). We used generalized linear mixed models to describe spatiotemporal variation in parasitic infection and each condition index. In general, living in the most heavily forested stream reaches, where hellbender density was highest, was associated with the greatest risk of parasitism, elevated neutrophil-to-lymphocyte (N:L) ratios and eosinophils, slightly lower hematocrit and lower mean body condition in hellbenders. All condition indices fluctuated temporally in a manner consistent with seasonal variation in hellbender metabolic demands and breeding phenology and were associated with land use during at least part of the year. Paradoxically, relatively low levels of forest cover appeared to confer a potential advantage to individuals in the form of release from parasites and improved body condition. Despite improved body condition, individuals from less forested areas failed to exhibit fluctuating body condition in response to spawning, which was typical in hellbenders from more forested habitats. We postulate this lack of fluctuation could be due to reduced conspecific competition or reproductive investment and/or high rates of filial cannibalism in response to declining forest cover.

Immune priming prior to pathogen exposure sheds light on the relationship between host, microbiome and pathogen in disease

Dynamic interactions between host, pathogen and host-associated microbiome dictate infection outcomes. Pathogens including Batrachochytrium dendrobatidis (Bd) threaten global biodiversity, but conservation efforts are hindered by limited understanding of amphibian host, Bd and microbiome interactions. We conducted a vaccination and infection experiment using Eastern hellbender salamanders (Cryptobranchus alleganiensis alleganiensis) challenged with Bd to observe infection, skin microbial communities and gene expression of host skin, pathogen and microbiome throughout the experiment. Most animals survived high Bd loads regardless of their vaccination status and vaccination did not affect pathogen load, but host gene expression differed based on vaccination. Oral vaccination (exposure to killed Bd) stimulated immune gene upregulation while topically and sham-vaccinated animals did not significantly upregulate immune genes. In early infection, topically vaccinated animals upregulated immune genes but orally and sham-vaccinated animals downregulated immune genes. Bd increased pathogenicity-associated gene expression in late infection when Bd loads were highest. The microbiome was altered by Bd, but there was no correlation between anti-Bd microbe abundance or richness and pathogen burden. Our observations suggest that hellbenders initially generate a vigorous immune response to Bd, which is ineffective at controlling disease and is subsequently modulated. Interactions with antifungal skin microbiota did not influence disease progression.

A novel bioaugmentation technique effectively increases the skin-associated microbial diversity of captive eastern hellbenders

Captive environments are maintained in hygienic ways that lack free-flowing microbes found in animals' natural environments. As a result, captive animals often have depauperate host-associated microbial communities compared to conspecifics in the wild and may have increased disease susceptibility and reduced immune function. Eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) have suffered precipitous population declines over the past few decades. To bolster populations, eastern hellbenders are reared in captivity before being translocated to the wild. However, the absence of natural microbial reservoirs within the captive environment diminishes the diversity of skin-associated bacteria on hellbender skin and may negatively influence their ability to defend against pathogenic species once they are released into the wild. To prepare hellbenders for natural bacteria found in riverine environments, we devised a novel bioaugmentation method to increase the diversity of skin microbial communities within a captive setting. We exposed juvenile hellbenders to increasing amounts of river water over 5 weeks before translocating them to the river. We genetically identified and phylogenetically compared bacteria collected from skin swabs and river water for alpha (community richness) and beta (community composition) diversity estimates. We found that hellbenders exposed to undiluted river water in captivity had higher alpha diversity and distinct differentiation in the community composition on their skin, compared to hellbenders only exposed to well water. We also found strong evidence that hellbender skin microbiota is host-specific rather than environmentally driven and is colonized by rare environmental operational taxonomic units in river water. This technique may increase hellbender translocation success as increasing microbial diversity is often correlated with elevated disease resistance. Future work is necessary to refine our methods, investigate the relationship between microbial diversity and hellbender health and understand how this bioaugmentation technique influences hellbenders' survival following translocation from captivity into the wild.

The soft-release of captive-born Kaiser’s Mountain Newt Neurergus kaiseri (Amphibia: Caudata) into a highland stream, western Iran

Captive breeding and reintroduction programs are important conservation tools and are used for increasing the number of plant and animal species worldwide.  The endemic Kaiser’s Mountain Newt Neurergus kaiseri is listed as Vulnerable on the Red List by the International Union for Conservation of Nature (IUCN) and is amended to Appendix I of the Convention of International Trade on Endangered Species (CITES).  In the present study, in order to learn about the survival ability of captive-born newts of N. kaiseri, we conducted a trial translocation of 15 two-year-old captive-born N. kaiseri into the highland stream in Sartakht Village, western Iran.  The survival rate of these newts were determined in two stages, involving early acclimatization in mesh bags and direct release in a highland brook.  In 12 surveys to the translocation site, a total of 86 individuals were identified during spring and summer.  The average survival rate during the acclimatizing phase was 98 ± 0.04 %, while an average survival rate of 12 ± 0.04 % was obtained when the newts were released in the brook.  Applying an average diurnal detection probability obtained for the Yellow Spotted Mountain Newt Neurergus derjugini, the overall survival rate in September when newts began the autumn withdrawal was 13%.  These findings demonstrate that captive-born N. kaiseri released into the wild in controlled conditions can survive during spring and summer and provide information for future reintroduction plan of this species.

Survival cost to relocation does not reduce population self-sustainability in an amphibian

Relocations are increasingly popular among wildlife managers despite often low rates of relocation success in vertebrates. In this context, understanding the influence of extrinsic (e.g., relocation design, habitat characteristics) and intrinsic factors (e.g., age and sex) on demographic parameters, such as survival, that regulate the dynamics of relocated populations is critical to improve relocation protocols and better predict relocation success. We investigated survival in naturally established and relocated populations of yellow-bellied toads (Bombina variegata), an amphibian that was nearly extinct in Belgium by the late 1980s. We quantified survival at three ontogenetic stages (juvenile, subadult, and adult) in the relocated population, the source population, and a control population. In the relocated population, we quantified survival in captive bred individuals and their locally born descendants. Then, using simulations, we examined how survival cost to relocation affects the self-sustainability of the relocated population. We showed that survival at juvenile and subadult stages was relatively similar in all populations. In contrast, relocated adult survival was lower than adult survival in the source and control populations. Despite this, offspring of relocated animals (the next generation, regardless of life stage) survived at similar rates to individuals in the source and control populations. Simulations revealed that the relocated population was self-sustaining under different scenarios and that the fate (e.g., stability or increase) of the simulated populations was highly dependent on the fecundity of relocated adults and their offspring. To summarize, our results indicate that survival in relocated individuals is lower than in non-relocated individuals but that this cost (i.e., reduced survival) disappears in the second generation. A finer understanding of how relocation affects demographic processes is an important step in improving relocation success of amphibians and other animals.

Survival cost to relocation does not reduce population self-sustainability in an amphibian

Relocations are increasingly popular among wildlife managers despite often low rates of relocation success in vertebrates. In this context, understanding the influence of extrinsic (e.g., relocation design, habitat characteristics) and intrinsic factors (e.g., age and sex) on demographic parameters, such as survival, that regulate the dynamics of relocated populations is critical to improve relocation protocols and better predict relocation success. We investigated survival in naturally established and relocated populations of yellow-bellied toads (Bombina variegata), an amphibian that was nearly extinct in Belgium by the late 1980s. We quantified survival at three ontogenetic stages (juvenile, subadult, and adult) in the relocated population, the source population, and a control population. In the relocated population, we quantified survival in captive bred individuals and their locally born descendants. Then, using simulations, we examined how survival cost to relocation affects the self-sustainability of the relocated population. We showed that survival at juvenile and subadult stages was relatively similar in all populations. In contrast, relocated adult survival was lower than adult survival in the source and control populations. Despite this, offspring of relocated animals (the next generation, regardless of life stage) survived at similar rates to individuals in the source and control populations. Simulations revealed that the relocated population was self-sustaining under different scenarios and that the fate (e.g., stability or increase) of the simulated populations was highly dependent on the fecundity of relocated adults and their offspring. To summarize, our results indicate that survival in relocated individuals is lower than in non-relocated individuals but that this cost (i.e., reduced survival) disappears in the second generation. A finer understanding of how relocation affects demographic processes is an important step in improving relocation success of amphibians and other animals.

Captivity-Induced Changes in the Skin Microbial Communities of Hellbenders (Cryptobranchus alleganiensis)

Variation in environmental conditions can result in disparate associations between hosts and microbial symbionts. As such, it is imperative to evaluate how environmental variables (e.g., habitat quality) can influence host-associated microbiome composition. Within wildlife conservation programs, captive conditions can negatively influence the establishment and maintenance of "wild-type" microbiotas within a host. Alternative microbial communities can result in the proliferation of disease among captive stock or upon reintroduction. Hellbenders (Cryptobranchus alleganiensis) are a threatened salamander for which extensive captive management is currently employed. Using metabarcoding, we characterized the skin microbiota of wild and captive hellbenders from two subspecies in the state of Missouri, the eastern (C. a. alleganiensis) and the Ozark hellbender (C. a. bishopi). Both subspecies in our study included wild adults and captive juveniles that were collected from the wild as eggs. Our objectives were to investigate differences in the skin microbial communities' richness/diversity, composition, and functional profiles of microbes between wild and captive individuals. Captive eastern hellbenders possessed richer communities than wild cohorts, whereas the opposite pattern was observed within the Ozark subspecies. We found significant microbial community structure between wild and captive populations of both subspecies. Microbiota structure translated into differences in the predicted metagenome of wild and captive individuals as well. As such, we can expect captive hellbenders to experience alternative microbial structure and function upon reintroduction into the wild. Our study provides a baseline for the effect of captivity on the skin microbial communities of hellbenders, and highlights the need to incorporate microbiota management in current captive-rearing programs.

Training for Translocation: Predator Conditioning Induces Behavioral Plasticity and Physiological Changes in Captive Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) (Cryptobranchidae, Amphibia)

Translocations are stressful, especially when captive animals are naïve to natural stimuli. Captive eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) identify predatory fish as threats, but may be more vulnerable to predation and stress because of inexperience with them. We investigated the use of predator conditioning to prepare hellbenders, behaviorally and physiologically, for the presence of a common predator, largemouth bass (Micropterus salmoides). We reared hellbenders for 30 d with and without continuous exposure to largemouth bass kairomones and heterospecific alarm cues and found conditioned hellbenders became less active compared to unconditioned individuals (p = 0.017). After conditioning, we exposed hellbenders to water, a low concentration of kairomones, or a high concentration of kairomones in a closed respirometer system. We measured activity within respirometer chambers and routine metabolic rate. We found unconditioned hellbenders exposed to low and high concentrations of kairomones were 41% and 119% more active than conditioned animals (p = 0.002 and p < 0.001). Moreover, conditioned individuals had on average 6.5% lower metabolic rates across all three kairomone concentrations compared to unconditioned individuals (p = 0.017). Our data suggest that predator conditioning induces behavioral avoidance tactics and physiological changes that could improve future translocation efforts for hellbenders and other imperiled species.

Cutaneous Microbial Community Variation across Populations of Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis)

Multicellular hosts maintain complex associations with microbial communities. While microbial communities often serve important functional roles for their hosts, our understanding of the local and regional processes that structure these communities remains limited. Metacommunity analyses provide a promising tool for investigating mechanisms shaping microbiome heterogeneity, which is essential for predicting functional variation between hosts. Using a metacommunity framework, we examined heterogeneity in the skin microbiome of the eastern hellbender (Cryptobranchus alleganiensis alleganiensis). Hellbenders are broadly distributed throughout river systems in the eastern United States, but are present in specific environmental locations throughout their range. The large range of the species and history of population fragmentation suggest that local and regional processes contribute to the distribution of cutaneous symbiont diversity. Therefore, we characterized the skin and environmental bacterial communities at eight rivers throughout the range of the species. We observed variation among hellbender populations in skin microbial community diversity and proportion of shared operational taxonomic units (OTUs) between animal and river water communities. Among populations sampled, we noted significant clumped OTU turnover (i.e., Clementsian structure) resulting in unique cutaneous communities. In addition, we observed a significant positive correlation between skin community divergence and hellbender population genetic divergence. Host-population skin community dissimilarity did not correlate strongly with distance between sampling locations, indicating a weak spatial effect on the distribution of symbionts. These results suggest that species sorting mechanisms (i.e., local processes) structure local skin microbial communities in hellbenders. The variation in skin community composition observed among host populations foreshadows a similar pattern in important functional characteristics (e.g., resistance to dysbiosis). Future work should focus on investigating forces shaping microbiome structure in eastern hellbenders, examining functional variation among populations, and evaluating effectiveness of microbiome management recommendations.

Characterization of the Cutaneous Bacterial Communities of Two Giant Salamander Subspecies

Pathogens currently threaten the existence of many amphibian species. In efforts to combat global declines, researchers have characterized the amphibian cutaneous microbiome as a resource for disease management. Characterization of microbial communities has become useful in studying the links between organismal health and the host microbiome. Hellbender salamanders (Cryptobranchus alleganiensis) provide an ideal system to explore the cutaneous microbiome as this species requires extensive conservation management across its range. In addition, the Ozark hellbender subspecies (Cryptobranchus alleganiensis bishopi) exhibits chronic wounds hypothesized to be caused by bacterial infections, whereas the eastern hellbender (Cryptobranchus alleganiensis alleganiensis) does not. We assessed the cutaneous bacterial microbiome of both subspecies at two locations in the state of Missouri, USA. Through 16S rRNA gene-based amplicon sequencing, we detected more than 1000 distinct operational taxonomic units (OTUs) in the cutaneous and environmental bacterial microbiome. Phylogenetic and abundance-based dissimilarity matrices identified differences in the bacterial communities between the two subspecies, but only the abundance-based dissimilarity matrix identified differences between wounds and healthy skin on Ozark hellbenders. The higher abundance of OTUs on Ozark wounds suggests that commensal bacteria present on the skin and environment may be opportunistically colonizing the wounds. This brief exploration of the hellbender cutaneous bacterial microbiome provides foundational support for future studies seeking to understand the hellbender cutaneous bacterial microbiome and the role of the bacterial microbiota on chronic wounds of Ozark hellbenders.

Reintroduction and Post-Release Survival of a Living Fossil: The Chinese Giant Salamander

Captive rearing and reintroduction / translocation are increasingly used as tools to supplement wild populations of threatened species. Reintroducing captive-reared Chinese giant salamanders may help to augment the declining wild populations and conserve this critically endangered amphibian. We released 31 captive-reared juvenile giant salamanders implanted with VHF radio transmitters at the Heihe River (n = 15) and the Donghe River (n = 16) in the Qinling Mountains of central China. Salamanders were monitored every day for survival from April 28^th 2013 to September 3^rd 2014. We attempted to recapture all living individuals by the end of the study, measured their body mass and total body length, and checked for abnormalities and presence of external parasites. Two salamanders at the Heihe River and 10 animals at the Donghe River survived through the project timeline. Nine salamanders were confirmed dead, while the status of the other 10 animals was undetermined. The annual survival rate of giant salamanders at the Donghe River (0.702) was 1.7-fold higher than that at the Heihe River (0.405). Survival increased as individuals were held longer following surgery, whereas body mass did not have a significant impact on survival rate. All salamanders recaptured from the Donghe River (n = 8) increased in mass (0.50 ± 0.13 kg) and length (5.5 ± 1.5 cm) after approximately 11 months in the wild, and they were only 7% lighter than wild animals of the same length (mean residual = -0.033 ± 0.025). Our results indicate that captive-reared Chinese giant salamanders can survive in the wild one year after release and adequate surgical recovery time is extremely important to post-release survival. Future projects may reintroduce older juveniles to achieve better survival and longer monitoring duration.

SURGICAL IMPLANTATION OF COELOMIC RADIOTRANSMITTERS AND POSTOPERATIVE SURVIVAL OF CHINESE GIANT SALAMANDERS (ANDRIAS DAVIDIANUS) FOLLOWING REINTRODUCTION

Worldwide, there are only a handful of reintroduction programs for threatened salamander species, and very few have conducted postrelease studies to examine survival, habitat selection, and dispersal. Limitations in postrelease monitoring are primarily due to size constraints of amphibians and to dimensions of the radiotransmitters available for implantation. However, due to the large size of the critically endangered Chinese giant salamander (Andrias davidianus), these animals make optimal candidates for surgical implantation of radiotransmitters prior to reintroduction or translocation. The objective of this study was to develop an anesthetic protocol using tricane methanesulfonate (MS-222) and test a surgical procedure for coelomic implantation of radiotransmitters for this species. A total of 32 Chinese giant salamanders from two age groups (Group A: 4.7 yr old, n = 16; Group B: 2.7 yr old, n = 16) were implanted with 4-g radiotransmitters designed for underwater monitoring of fish. Group A was held 16 wk before release while Group B was held 6 wk before release, and the salamanders' survival and postoperative complications recorded for the first month postrelease. Group A animals took longer to reach a surgical plane of anesthesia than did Group B animals, and this was directly correlated to mass of the animals. Postsurgery, one animal from Group B died of dehiscence before release while 83.9% animals survived after the first month in the wild. All of the animals that died postrelease were from Group B; three animals experienced dehiscence of the suture site and died while another two animals expired from trauma and fungal infection, respectively. Improvements for future studies include use of alternative suture material for closure after implantation and additional healing time of the incision.

Haematological and immunological characteristics of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) infected and co-infected with endo- and ectoparasites

Disease is among the leading causes of the global decline in amphibian populations. In North America, parasites and pathogens are among the factors implicated in precipitous population declines of the giant hellbender salamander (Cryptobranchus alleganiensis), but the incidence of infections and the responses of hellbenders to infections remain poorly studied. Here, we document the prevalence of leech and trypanosome infections in a wild population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) and describe haematological and immunological characteristics of hellbenders harbouring these infections. We hypothesized that hellbenders parasitized by trypanosomes would be anaemic, that individuals infected with either or both parasites would exhibit shifts in white blood cell counts and that hellbenders infected with leeches would exhibit altered plasma bactericidal capacity. We found that 24 and 68% of hellbenders in our sample population were infected with leeches and trypanosomes, respectively, and 20% were co-infected with both parasites. We found no evidence suggestive of anaemia among infected individuals. However, hellbenders infected with either or both parasites exhibited marked shifts in circulating white blood cells that were consistent with predictable responses to parasitic infection. Additionally, we found that hellbenders harbouring leeches had much higher plasma bactericidal capacity than individuals without leeches, and we offer multiple potential mechanistic explanations for this observation. We also found evidence that cellular and serological immune responses to parasites were less robust in juvenile than adult hellbenders. This finding warrants further investigation in light of the demographic characteristics, specifically the scarcity of juvenile age classes, of hellbender populations where disease is a possible contributor to declines. Finally, we describe two methodological advances that will improve future studies seeking to diagnose trypanosome infections and to test the bactericidal capacity of hellbenders and perhaps other amphibians. Our study provides fundamental insights into how hellbenders respond physiologically to endo- and ectoparasites, which could ultimately prove useful for their conservation.

Genetic analysis reveals multiple parentage in captive reared eastern hellbender salamanders (Cryptobranchus alleganiensis)

Information on the parentage of captive reared clutches is vital for conservation head-starting programs. Molecular methods, such as genotyping individuals with hyper-variable markers, can elucidate the genealogical contribution of captive-reared, reintroduced individuals to native populations. In this study, we used 12 polymorphic microsatellite loci to infer parentage of a clutch of 18 eastern hellbenders collected from a single nest from Buffalo Creek, West Virginia, subsequently reared in captivity, and used for translocations in Indiana. Collectively, these markers successfully detected the presence of multiple parentage for this species of conservation concern presently used in captive management programs in zoos across many states. This study highlights the need for genetic analysis of captive reared clutches used in translocations to minimize the loss of genetic diversity and potential for genetic swamping at release sites.

Evidence of ectoparasite-induced endocrine disruption in an imperiled giant salamander, the eastern hellbender (Cryptobranchus alleganiensis)

Parasitic leeches and trypanosomes release chemical signals into their hosts to evade immuno-detection, but it is unknown whether these compounds manipulate host behavior or endocrine physiology. We determined whether parasitic infections with leeches and/or trypanosomes affected the immune and stress response of an imperiled giant species of amphibian, the eastern hellbender (Cryptobranchus alleganiensis Daudin). We monitored corticosterone and white blood cell counts in response to restraint and injection with adrenocorticotropin hormone (ACTH) or saline for up to 50 h. The presence of leeches dampened hellbender corticosterone responses to restraint and reduced diel patterns of plasma corticosterone. Injection with ACTH restored the normal inter-renal responses of hellbenders, suggesting that leeches, possibly through neurotransmitters in leech saliva, cause down-regulation of corticosterone release at the level of the pituitary or hypothalamus. Infection with leeches also increased the relative abundance of eosinophils, white blood cells often recruited into circulation in response to parasitic infection. Lastly, neutrophil to lymphocyte (N:L) ratios increased in all animals after 24 h of capture and remained elevated for up to 50 h, but these temporal dynamics did not differ with parasite infection. Trypanosome infection did not affect any aspect of hellbender physiology that we measured. Our findings reveal a previously undocumented host-parasite dynamic. While the functional significance to the parasite is unclear, the physiological and behavioral implications for the host are great, given the important role of glucocorticoids in regulating physiology and behavior.

Morphological and molecular characterization of a new species of leech (Glossiphoniidae, Hirudinida): Implications for the health of its imperiled amphibian host (Cryptobranchus alleganiensis)

The hellbender (Cryptobranchus alleganiensis) is among the most intriguing and imperiled amphibians in North America. Since the 1970s and 80s, western populations of the Ozark and eastern subspecies in Missouri have declined by nearly 80%. As a result of population declines, the Ozark hellbender was recently federally protected as an endangered species, and the eastern subspecies was granted protection under CITES. Although habitat degradation is probably the biggest threat to hellbender populations, recent evidence suggests that pathogens including chytrid fungus and “flesh-eating” bacteria may also contribute to declines in Ozark hellbenders. Leeches, which are very common on Ozark hellbenders, have recently been implicated as possible vectors of disease among Ozark hellbenders but have not been described in eastern hellbenders or outside of Missouri and Arkansas. We discovered a population of leeches on eastern hellbenders in southwest Virginia and confirmed that the species of leech is within the genus Placobdella, but is morphologically and genetically distinct from all previously described leech species. We named the new species Placobdella appalachiensissp. n. Moser and Hopkins, based on the mountainous region in which it was discovered. Our surveys over a three consecutive year period suggested that this leech species may be patchily distributed and/or have a narrow geographic range. We consistently detected leeches at one site (mean prevalence in 80 hellbenders = 27.5%; median intensity = 3.0 leeches per parasitized hellbender [range 1 – >250 leeches]) during three years of surveys, but we never found leeches in any of our other seven study sites in two streams (mean prevalence in 139 hellbenders = 0%). We found a significant positive relationship between hellbender body size and the intensity of parasitism, and we suggest the possibility that the behavioral ecology of adults leading up to reproduction may increase their encounter rates with parasites. We discuss the potential conservation implications of discovery of leeches in this stream, and make recommendations for future mitigation and monitoring efforts.

Allegheny woodrat (Neotoma magister) captive propagation to promote recovery of declining populations

The Allegheny woodrat (Neotoma magister) is endemic to the eastern United States with local distributions restricted to rocky habitats within deciduous forests. Over the last 40 years, woodrats have declined precipitously due to an array of human-mediated pressures. There is growing interest in the captive propagation of woodrats as a tool to promote in situ conservation, but their solitary social structure, territorial behavior, and low fecundity present challenges for the attainment of levels of ex situ reproduction sufficient to support reintroduction programs. In 2009 we established a captive breeding program with 12 wild-caught individuals (4.8) collected from Indiana and Pennsylvania. Restricting breeding to wild-caught individuals, over 26 months we produced 19 litters comprised of 43 pups (26.17), of which 40 (24.16) survived to weaning. In sum, wild-caught individuals readily habituated to the captive environment and the low fecundity of woodrats was offset by high survival rates for both adults and juveniles. Therefore, when managed appropriately, captive Allegheny woodrat populations should be capable of supporting the release of surplus individuals to augment in situ conservation measures.