Woodrat Populations Research Articles

A RANGE-WIDE ECTOPARASITE SURVEY FOR ALLEGHENY WOODRATS (NEOTOMA MAGISTER).

Allegheny woodrats (Neotoma magister) are karst-specializing rodents that are rare or in conservation need in many states within their current range. Parasitism and habitat fragmentation have been suggested as primary reasons for declining populations. The presence, prevalence, and impact of ectoparasites, including fleas, ticks, and bots, is not fully understood rangewide. We collected Allegheny woodrat ectoparasites across 8 states in their range, identifying parasites via morphological and genetic means. Across contributions from 8 states, we discovered 2 woodrat-specific fleas parasitizing Allegheny woodrats: Orchopeas pennsylvanicus (all contributing states, n = 228) and Epitedia cavernicola (Indiana only, n = 9). The former was a new state record in New Jersey and Ohio. Woodrat specialists Ixodes woodi were morphologically identified as the dominant tick species (n = 38), and our contributions to genetic databases may ease confusion in future efforts. Three generalist species of ticks representing 8 individuals were identified as Dermacentor variabilis, Amblyomma americanum, and Ixodes scapularis. Only 2 bot fly species were recognized in Allegheny woodrats: 1 squirrel bot (Cuterebra emasculator) and 10 individuals of Cuterebra sp. not genetically conspecific to any known eastern U.S. rodent bot. The host specificity for fleas is not surprising, given that previous small-scale surveys and ticks primarily appear to be a mix of genus-specific (Ixodes woodi) and generalist species. There remains uncertainty with bots via morphological and genetic analyses. Our survey presents a wide-ranging baseline survey for Allegheny woodrats across their range, emphasizing the diversity (or specificity) of parasite groups for this species. An understanding of Allegheny woodrats and the health impact of ectoparasites is imperative because they face myriad challenges rangewide, especially considering the bot-driven demise of 1 woodrat in our study. Ectoparasites can have a marked impact on already-declining woodrat populations across their range and should not be overlooked in future surveys.

Raccoon Roundworm (Baylisascaris procyonis) Undetected in Endangered Key Largo Woodrat (Neotoma floridana smalli) Endemic Range.

Raccoon roundworm (Baylisascaris procyonis) negatively affects woodrat (Neotoma spp.) populations but is not known to occur in the endemic range of endangered Key Largo woodrats (Neotoma floridana smalli). Rectal swabs from 23 raccoons (Procyon lotor) in Key Largo were screened for raccoon roundworm by PCR. All tests were negative, suggesting continued absence.

Observation of an Interaction between an Allegheny Woodrat (Neotoma magister) and a Timber Rattlesnake (Crotalus horridus) in Pennsylvania

Neotoma magister (Allegheny Woodrat) is a threatened species in Pennsylvania and listed as Endangered in 4 of 5 bordering states. Declining food resources, genetic isolation, habitat fragmentation, disease, and increasing predator populations are considered the primary threats to Allegheny Woodrat populations. Herein, we share an observation captured on a wildlife camera of an adult woodrat displaying agonistic behavior toward a small Crotalus horridus (Timber Rattlesnake).

Activity Patterns of Allegheny Woodrats (Neotoma magister) and Two Potential Competitors in Virginia

Neotoma magister (Allegheny Woodrat) is a nocturnal, emergent rock-habitat specialist (i.e., inhabits rocky outcrops, boulderfields, and caves). Woodrat populations have declined range-wide due to habitat fragmentation, endoparasites, and interspecific competition. We estimated the diel activity curves of Allegheny Woodrats and assessed the effects of habitat type (exposed rock habitat/cave-exterior vs. cave-interior) and season (spring, summer, and fall) on curve shape. We also investigated the effect of 2 granivorous competitors' presence and activity curves (Peromyscus spp. and Tamias striatus [Eastern Chipmunk]) on woodrat activity. Additionally, we investigated whether the presence or absence of Procyon lotor (Raccoon), a primary carrier of Baylisascaris procyonis (Raccoon Roundworm), significantly affects the presence or absence of Allegheny Woodrats. We used remote-detecting cameras to document the diel cycles of Allegheny Woodrats and 2 competitors across 83 sites in western Virginia and 2 sites in West Virginia from 2017 to 2022. For 13,002 recorded events, we detected woodrats at 36 of 85 sites (3778 camera events). We observed a higher proportion of daytime activity by woodrats within cave interiors than cave exteriors. Allegheny Woodrat activity curves differed among seasons, with the greatest differences observed between summer and fall and with ∼80% activity overlap. These activity curves differed significantly when co-occurring with versus not co-occurring with a competitor. Additionally, Allegheny Woodrats showed an inverse activity rate with Peromyscus spp. Thus, our results suggest that competition avoidance via temporal partitioning occurs between these species. Allegheny Woodrats and Raccoons occurred together more often than expected suggesting the presence of woodrats is currently not reduced by the presence of Raccoons. Our remote-detecting camera data help elucidate relationships of Allegheny Woodrats with presumptive competitors, and open avenues for further investigation in Virginia.

A novel SNP assay reveals increased genetic variability and abundance following translocations to a remnant Allegheny woodrat population

BackgroundAllegheny woodrats (Neotoma magister) are found in metapopulations distributed throughout the Interior Highlands and Appalachia. Historically these metapopulations persisted as relatively fluid networks, enabling gene flow between subpopulations and recolonization of formerly extirpated regions. However, over the past 45 years, the abundance of Allegheny woodrats has declined throughout the species’ range due to a combination of habitat destruction, declining hard mast availability, and roundworm parasitism. In an effort to initiate genetic rescue of a small, genetically depauperate subpopulation in New Jersey, woodrats were translocated from a genetically robust population in Pennsylvania (PA) in 2015, 2016 and 2017. Herein, we assess the efficacy of these translocations to restore genetic diversity within the recipient population.ResultsWe designed a novel 134 single nucleotide polymorphism panel, which was used to genotype the six woodrats translocated from PA and 82 individuals from the NJ population captured before and after the translocation events. These data indicated that a minimum of two translocated individuals successfully produced at least 13 offspring, who reproduced as well. Further, population-wide observed heterozygosity rose substantially following the first set of translocations, reached levels comparable to that of populations in Indiana and Ohio, and remained elevated over the subsequent years. Abundance also increased during the monitoring period, suggesting Pennsylvania translocations initiated genetic rescue of the New Jersey population.ConclusionsOur results indicate, encouragingly, that very small numbers of translocated individuals can successfully restore the genetic diversity of a threatened population. Our work also highlights the challenges of managing very small populations, such as when translocated individuals have greater reproductive success relative to residents. Finally, we note that ongoing work with Allegheny woodrats may broadly shape our understanding of genetic rescue within metapopulations and across heterogeneous landscapes.

Toxin tolerance across landscapes: Ecological exposure not a prerequisite.

Little is known about the tolerances of mammalian herbivores to plant specialized metabolites across landscapes.We investigated the tolerances of two species of herbivorous woodrats, Neotoma lepida (desert woodrat) and Neotoma bryanti (Bryant's woodrat) to creosote bush (Larrea tridentata), a widely distributed shrub with a highly toxic resin. Woodrats were sampled from 13 locations both with and without creosote bush across a 900 km transect in the US southwest. We tested whether these woodrat populations consume creosote bush using plant metabarcoding of feces and quantified their tolerance to creosote bush through feeding trials using chow amended with creosote resin.Toxin tolerance was analyzed in the context of population structure across collection sites with microsatellite analyses. Genetic differentiation among woodrats collected from different locations was minimal within either species. Tolerance differed substantially between the two species, with N. lepida persisting 20% longer than N. bryanti in feeding trials with creosote resin. Furthermore, in both species, tolerance to creosote resin was similar among woodrats near or within creosote bush habitat. In both species, woodrats collected greater than 25 km from creosote had markedly lower tolerances to creosote resin compared to animals from within the range of creosote bush.The results imply that mammalian herbivores are adapted to the specialized metabolites of plants in their diet, and that this tolerance can extend several kilometers outside of the range of dietary items. That is, direct ecological exposure to the specialized chemistry of particular plant species is not a prerequisite for tolerance to these compounds. These findings lay the groundwork for additional studies to investigate the genetic mechanisms underlying toxin tolerance and to identify how these mechanisms are maintained across landscape-level scales in mammalian herbivores.

Trees, owls, worms, and crevices: which habitat factors predict local woodrat demographics?

Abstract Hypothesized reasons for the decline of many woodrat populations in the eastern United States include parasitism by raccoon roundworm (Baylisascaris procyonis; Ascaridida: Ascarididae), hard mast shortages, owl predation, and reductions in suitable structures (e.g., rock crevices) for nest construction. We investigated whether abundance and apparent survival of eastern woodrats (Neotoma floridana) within a successfully reintroduced metapopulation in southern Illinois could be predicted by factors underlying these hypothesized reasons for woodrat declines. We analyzed capture histories of 205 eastern woodrats from eight rock outcrop sites in summers of 2013 and 2014 to estimate local population size and apparent survival. We then used repeated-measures models to test how woodrat abundance and apparent survival were associated with availability of mast trees, owl abundance, risk of raccoon roundworm infection, and crevice availability. Mean monthly estimated woodrat abundance at sites ranged from 0.78 to 21.58 in 2013 and 0.48 to 18.08 in 2014, while monthly apparent survival ranged from 0.00 to 0.76 during the summers and 0.05 to 0.90 during the trapping intersession. Crevice availability was positively associated both with abundance and apparent survival of woodrats. Our results did not support the hypothesis that owls reduce woodrat populations because woodrat abundance was positively associated with owl abundance across sites. No raccoon roundworm eggs were found at any site. We conclude that crevice availability was the best predictor of woodrat population success in our study area, while owl abundance may be a proxy for other habitat variables or a response to woodrat abundance. Our findings suggest measures that could be taken to benefit woodrat survival and abundance.

Plant secondary compound- and antibiotic-induced community disturbances improve the establishment of foreign gut microbiota.

Fecal transplants are a powerful tool for manipulating the gut microbial community, but how these non-native communities establish in the presence of an intact host gut microbiome is poorly understood. We explored the microbiome of desert woodrats (Neotoma lepida) to determine whether disrupting existing microbial communities using plant secondary compounds (PSCs) or antibiotics increases the establishment of foreign microbes. We administered two fecal transplants between natural populations of adult woodrats that harbor distinct gut microbiota and have different natural dietary exposure to PSCs. First, we administered fecal transplants to recipients given creosote resin, a toxin found in the natural diet of our "donor" population, and compared the gut microbial communities to animals given fecal transplants and control diet using 16S rRNA gene sequencing. Second, we disrupted the gut microbial community of the same recipients with an antibiotic prior to fecal transplants. We found that gut microbial communities of woodrats disrupted with PSCs or antibiotics resembled that of donors more closely than control groups. PSC treatment also enriched microbes associated with metabolizing dietary toxins in transplant recipients. These results demonstrate that microbial community disturbances by PSCs or antibiotics are sufficient to facilitate establishment of foreign microbes in animals with intact microbiomes.

Reproductive success of captive-reared Allegheny Woodrats (Neotoma magister) released into genetically depauperate populations

Habitat fragmentation and degradation have led to a proliferation of small and isolated populations that are vulnerable to genetic erosion. Reduction in habitat and concomitant declines in population connectivity can expediate the collapse of species that exist as natural metapopulations. In recent years, Allegheny woodrats (Neotoma magister) have experienced local extirpations and declines in genetic diversity across their range due to disease-related mortality, reduced food availability, and disruption of connectivity among subpopulations. In response, we developed a captive-breeding program to facilitate genetic management of isolated woodrat populations in Indiana. Between 2010 and 2012, 27 captive-reared individuals were released to four sites with declining woodrat abundance. We used 99 single nucleotide polymorphisms and 11 microsatellite loci to genotype sympatric woodrats from the four sites, sampled before and after the release of captive-reared individuals, to: (1) evaluate the post-release reproductive success of captive-reared individuals and (2) characterize changes in genetic diversity. A minimum of five of the 27 captive-reared woodrats produced at least 20 offspring, 11 of which were sired by a single male. One site exhibited increased abundance by the end of the monitoring period, although genetic variability decreased. Two sites experienced population declines in concert with fluctuating genetic variability. The last site showed comparable abundance at the beginning and end of the monitoring period, with an increase in observed heterozygosity. Our results indicate that captive-reared woodrats were, in some cases, able to reproduce in the wild, interbreed with residents and increase genetic diversity and abundance among small, isolated subpopulations.

Effects of Prescribed Fire on Site Occupancy of Allegheny Woodrats (Neotoma magister) in a Mixed-Oak Forest in South-Central Pennsylvania

Prescribed fire has increasingly been used to manage and restore eastern oak (Quercus spp.) forests. Fire has the potential to influence habitat use by forest-dwelling small mammals, including species of conservation concern such as the Allegheny woodrat (Neotoma magister). Thus, an understanding of how Allegheny woodrats respond to habitat changes caused by fire is of increasing importance. We investigated the effects of prescribed fire on a population of Allegheny woodrats in a mixed-oak forest in south-central Pennsylvania. We surveyed 18 rock outcrops for Allegheny woodrats using remote game cameras in September–October 2019. We fit single-season occupancy models in Program PRESENCE to examine the effects of site covariates related to burn history (burned or unburned) and burn frequency (number of burns), topography, and vegetation structure and composition on occupancy (Ψ) of Allegheny woodrats while accounting for imperfect detection (p). In 252 camera trap-nights, we recorded 356 detections of Allegheny woodrats at 50% of sites surveyed. Top-ranked occupancy models (ΔAICc ≤ 2) indicated that Allegheny woodrat occupancy was positively related to burn frequency, overstory tree species richness, and elevation; however, the effects of these covariates were not significant. Our results suggest that low-intensity prescribed fire implemented at moderate (3–5 y) return intervals in oak forests is unlikely to impact Allegheny woodrat populations, but the effects of more frequent and intense fires remain unknown. Additional studies are needed to determine how Allegheny woodrats respond to post-fire vegetation regrowth and recovery over time.

Climatic factors and population demography in big-eared woodrat,Neotoma macrotis

AbstractChanges in temperature and rainfall patterns can have marked impacts on small mammal populations that inhabit environments with highly fluctuating water availability. With projected increases in droughts and fewer but more intense rainfall events in the Southwestern United States, the persistence of many wildlife populations may be threatened. Our goal was to assess how temperature and rainfall during distinct dry and wet seasons influenced the dynamics of a population of big-eared woodrats (Neotoma macrotis) in a mixed oak woodland of coastal central California. We applied Pradel’s temporal symmetry models to our 21-year biannual capture–mark–recapture data set (1993–2014) to determine the effects of climatic factors on the woodrats’ apparent survival (Φ) and recruitment rate (f). Monthly Φ averaged 0.945 ± 0.001 and varied with season. Monthly f was 0.064 ± 0.001 in the wet season (f was fixed to 0 in the dry season). Monthly population growth rate (λ) varied from 0.996 ± 0.001 during the dry season to 1.001 ± 0.001 during the wet season, which indicated a stable population (0.999 ± 0.001). Total rainfall from the previous season and mean temperature during the same season positively influenced Φ and f. By contrast, Φ and f were negatively influenced by mean temperature from the previous season and total rainfall in the same season. The resulting λ fluctuated with total rainfall, particularly in the wet season. Our results suggest that the big-eared woodrat population may not be substantially affected by warm temperatures per se, potentially because of the microclimate provided by its stick houses. We also discuss its adaptability to local food resources and relatively slow life history relative to other cricetids, and propose that the big-eared woodrat population may be equipped to cope with future climate change.

The Prevalence of the Raccoon Roundworm, Baylisascaris procyonis, in Allegheny Woodrat Habitat in the Mid-Atlantic Region, U.S.A.

Baylisacaris procyonis is a roundworm that is tolerated by its primary host, raccoons (Procyon lotor). However, this roundworm can be fatal to intermediate mammalian hosts and may be a contributing factor to population declines of the endangered, Allegheny woodrat (Neotoma magister). We used fecal flotation to determine the prevalence of B. procyonis eggs in raccoon scat found in locations that overlap with where woodrats persist in the mid-Atlantic. We determined that B. procyonis was present at two extant woodrat colonies in Maryland and Pennsylvania. We expect woodrat populations at these sites to decline, if the roundworm and other factors (e.g., forest fragmentation) are not alleviated.

The Prevalence of the Raccoon Roundworm, Baylisascaris procyonis, in Allegheny Woodrat Habitat in the Mid-Atlantic Region, U.S.A.

Baylisacaris procyonis is a roundworm that is tolerated by its primary host, raccoons (Procyon lotor). However, this roundworm can be fatal to intermediate mammalian hosts and may be a contributing factor to population declines of the endangered, Allegheny woodrat (Neotoma magister). We used fecal flotation to determine the prevalence of B. procyonis eggs in raccoon scat found in locations that overlap with where woodrats persist in the mid-Atlantic. We determined that B. procyonis was present at two extant woodrat colonies in Maryland and Pennsylvania. We expect woodrat populations at these sites to decline, if the roundworm and other factors (e.g., forest fragmentation) are not alleviated.

Status of Eastern Woodrats in Isolated Remnant Populations Following Genetic Augmentation and Habitat Disturbance

In Illinois, Neotoma floridana (Eastern Woodrat) experienced range reductions and population bottlenecking over the past century. During the period 2004–2005, the isolated remnant populations along the Mississippi bluffs in southwestern Illinois were genetically augmented with 47 Eastern Woodrats from Arkansas and Missouri, resulting in 40% admixture within the largest population. In 2009, a strong windstorm created canopy gaps and woody debris throughout this area, potentially improving habitat for Eastern Woodrats. We investigated the status of Eastern Woodrat populations in southwestern Illinois by livetrapping remnant populations and conducting sign surveys from 2011 to 2015. We captured 263 Eastern Woodrats; mean trapping success was 62.5% higher than trapping during the 1990s, and the number of individuals captured per trap-night was 3–6 times higher than trapping events during the previous 18 years (all P <0.001). We also located sign of Eastern Woodrat 8.9 km east of the remnant populations. We recommend further genetic monitoring to evaluate whether population increases are coupled with increased admixture and recommend forest-management actions that create habitat disturbance and resultant piles of woody debris that increase woodrat habitat quality.

Spatial clustering of Borrelia burgdorferi sensu lato within populations of Allen's chipmunks and dusky-footed woodrats in northwestern California.

The ecology of Lyme borreliosis is complex in northwestern California, with several potential reservoir hosts, tick vectors, and genospecies of Borrelia burgdorferi sensu lato. The primary objective of this study was to determine the fine-scale spatial distribution of different genospecies in four rodent species, the California ground squirrel (Otospermophilus beecheyi), northern flying squirrel (Glaucomys sabrinus), dusky-footed woodrat (Neotoma fuscipes), and Allen’s chipmunk (Neotamias senex). Rodents were live-trapped between June 2004 and May 2005 at the Hoopa Valley Tribal Reservation (HVTR) in Humboldt County, California. Ear-punch biopsies obtained from each rodent were tested by polymerase chain reaction (PCR) and sequencing analysis. The programs ArcGIS and SaTScan were used to examine the spatial distribution of genospecies. Multinomial log-linear models were used to model habitat and host-specific characteristics and their effect on the presence of each borrelial genospecies. The Akaike information criterion (AICc) was used to compare models and determine model fit. Borrelia burgdorferi sensu stricto was primarily associated with chipmunks and B. bissettiae largely with woodrats. The top model included the variables “host species”, “month”, and “elevation” (weight = 0.84). Spatial clustering of B. bissettiae was detected in the northwestern section of the HVTR, whereas B. burgdorferi sensu stricto was clustered in the southeastern section. We conclude that the spatial distribution of these borreliae are driven at least in part by host species, time-of-year, and elevation.

Mitochondrial genome of an Allegheny Woodrat (Neotoma magister)

The Allegheny woodrat (Neotoma magister) is endemic to the eastern United States. Population numbers have decreased rapidly over the last four decades due to habitat fragmentation, disease-related mortality, genetic isolation and inbreeding depression; however, effective management is hampered by limited genetic resources. To begin addressing this need, we sequenced and assembled the entire Allegheny woodrat mitochondrial genome. The genome assembly is 16,310 base pairs in length, with an overall base composition of 34% adenine, 27% thymine, 26% cytosine and 13% guanine. This resource will facilitate our understanding of woodrat population genetics and behavioral ecology.

A test of Darwin's 'lop-eared' rabbit hypothesis.

Integration of evolutionary and developmental biology has stimulated novel insights on the origins and maintenance of phenotypic variation. For instance, phenotypic accommodation predicts that trait covariance originates via a novel developmental input caused by genetic change in one trait, but not the other. Darwin provided a striking example of this process in the 'lop-eared' rabbit by demonstrating that artificial selection for long external ears induced variation in the external auditory meatus. Although this intriguing pattern has been interpreted as evidence of phenotypic accommodation, it is unclear whether it exists and, if it does, whether it is selectively maintained in nature. To address this concern, we examined trait covariance in natural woodrat populations that have likely undergone selection for long ears. We demonstrated a remarkably similar covariance pattern as in the 'lop-eared' rabbit, which was associated with climatic variables along a steep arid-to-moist longitudinal gradient. Thus, our results suggest that trait covariance is likely a correlated response to selection. We relate these findings to potential origins of trait covariance owing to altered developmental interactions, such as in phenotypic accommodation. Additional evidence is needed to clarify how phenotypic accommodation and correlated selection promote and maintain trait covariance in natural populations. Nonetheless, our study is the first to support a classic Darwinian example concerning domestication and natural selection.

Allegheny woodrat hard mast preference and response to food supplementation

ABSTRACTRange‐wide declines of the Allegheny woodrat (Neotoma magister) have been attributed, in part, to reductions in mast associated with extirpation of American chestnut (Castanea dentata) and transition to oak (Quercus)‐dominated forests prone to periodic mast failure. Chestnuts produce mast more consistently than oaks; hence, efforts to restore a blight‐resistant hybrid chestnut may facilitate woodrat recovery. Our goal was to describe the implications of chestnut restoration for imperiled Allegheny woodrat populations. Our objectives were to evaluate woodrat preferences for American chestnuts, blight‐resistant hybrid chestnuts, and other hard mast items and to describe the response of woodrats to artificial increases in mast availability. From 2011 to 2013, we conducted a series of cafeteria‐style experiments among woodrat populations in southern Indiana in which we used remote cameras to quantify woodrat preferences for various mast items. Additionally, we introduced an abundance of mast into occupied den sites and evaluated differences in apparent survival, apparent recruitment, population growth rate, and body mass between mast‐supplemented and control populations. Discrete choice modeling revealed that woodrats preferentially removed northern red oak (Q. rubra) and black oak (Q. velutina) acorns over chestnuts and other seed types (i.e., hickories [Genus spp.], walnuts [Genus spp.]). Further, woodrats preferred American over hybrid chestnuts, suggesting that these seeds were not perceived as equivalent food resources. Apparent survival, apparent recruitment, population growth rate, and body mass did not differ between supplemented and control populations. Although chestnuts, as annually consistent mast producers, may benefit woodrat populations by reducing the risk of complete mast failure, our results suggest that the restoration of chestnut mast is unlikely to benefit woodrat populations during years of abundant acorn production. Accordingly, managers should foster a diverse and abundant oak community to ensure sufficient acorn resources are available to sustain woodrat populations as chestnut restoration efforts progress. © 2015 The Wildlife Society.

Fine-scale genetic structure of woodrat populations (Genus: Neotoma) and the spatial distribution of their tick-borne pathogens

Dusky-footed woodrats are territorial cricetid rodents that individually occupy large stick houses from which they foray to gather food, find mates, and engage in other activities. These rodents are often bitten by Ixodes spp. ticks and are reservoirs of some strains of tick-borne bacterial pathogens such as Anaplasma phagocytophilum and Borrelia burgdorferi. Limited dispersal by hosts and vectors could create fine-scale population structure where related hosts and pathogen exposure are co-distributed in space. To quantify population genetic structure and infection status, we genotyped 167 woodrats using a panel of 15 microsatellite loci from three northern California study sites: Soquel (SD), Cold Canyon (CC), and Quail Ridge (QR). We used quantitative PCR and serology to test for infection with A. phagocytophilum and B. burgdorferi. All three populations maintained similar, moderately high levels of genetic variation. For A. phagocytophilum, the PCR-prevalence was higher at SD (30.0%) than CC (13%) and QR (7%) whereas the seroprevalence was similar at all three sites (13–18%). The B. burgdorferi PCR-prevalence at CC was 11%, no woodrats were PCR-positive at QR, and none were tested at SD. We found a negative correlation between pairwise genetic relatedness and spatial distance with the majority of highest order relatives occurring within 200m of one another. Related dyads were more likely to be adult females than males, suggesting that adult female residents are the primary source of spatially proximate, high-order relatives in woodrat populations. Despite spatial genetic clustering of hosts, our spatial window test found no significant clustering of pathogens. Woodrats that were seropositive for A. phagocytophilum had higher heterozygosity than seronegative woodrats, which could be consistent with genetically diverse individuals having greater capacity to mount an immune response. Overall, our analyses show that limited dispersal of individual woodrats leads to fine-scale genetic structure within populations. Genetic structure, coupled with the limited dispersal of I. pacificus ticks could result in disease dynamics that are uniquely restricted to small spatial scales. By combining host genetic and disease studies we are able to infer limited dispersal and structured populations among hosts which affect infectious disease clustering and dynamics.

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.