Jeff Beringer

Factors affecting capture myopathy in white-tailed deer

Capture myopathy can be a significant cause of mortality for white-tailed deer (Odocoileus virginianus) and other ungulates. Capture and handling may affect rates of myopathy. During 1988-92 we captured 415 white-tailed deer with rocket-nets and Clover traps as part of a deer mortality study in northcentral Missouri. We placed radiotransmitters on 250 of these deer and assumed capture myopathy was the cause of death for 23 deer that died within 26 days of capture. All myopathy suspects were captured with rocket-nets. We examined differences in 6 handling variables for rocket-net-captured deer that died within 26 days of capture and those that lived more than 26 days. We fit a Cox proportional hazard model to these data to determine the capture variables most affecting myopathy for deer captured with rocket-nets. Survival of captured deer was most influenced by the number of deer captured together. Process times should be minimized to reduce stress to captured deer.

River Otter Population Size Estimation using Noninvasive Latrine Surveys

ABSTRACT Across much of North America, river otter (Lontra canadensis) populations were extirpated or greatly reduced by the early 20th century. More recently, reintroductions have resulted in restored populations and the recommencement of managed trapping. Perhaps the best example of these river otter reintroductions occurred in Missouri, regarded as one of the most successful carnivore recovery programs in history. However, abundance estimates for river otter populations are difficult to obtain and often contentious when used to underpin management activities. We assessed the value of latrine site monitoring as a mechanism for quantifying river otter abundance. Analyses of fecal DNA to identify individual animals may result in an improved population estimate and have been used for a variety of mammal species. We optimized laboratory protocols, redesigned existing microsatellite primers, and calculated genotyping error rates to enhance genotyping success for a large quantity of river otter scat samples. We also developed a method for molecular sexing. We then extracted DNA from 1,421 scat samples and anal sac secretions (anal jelly) collected during latrine site counts along 22–34-km stretches representing 8–77% of 8 rivers in southern Missouri in 2009. Error rates were low for the redesigned microsatellites. We obtained genotypes at 7–10 microsatellite loci for 24% of samples, observing highest success for anal jelly samples (71%) and lowest for fresh samples (collected within 1 day of defecation). We identified 63 otters (41 M, 22 F) in the 8 rivers, ranging from 2 to 14 otters per river. Analyses using program CAPWIRE resulted in population estimates similar to the minimum genotyping estimate. Density estimates averaged 0.24 otters/km. We used linear regression to develop and contrast models predicting population size based on latrine site and scat count indices, which are easily collected in the field. Population size was best predicted by a combination of scats per latrine and latrines per kilometer. Our results provide methodological approaches to guide wildlife managers seeking to initiate similar river otter fecal genotyping studies, as well as to estimate and monitor river otter population sizes.

Distribution and prevalence of Cytauxzoon felis in bobcats (Lynx rufus), the natural reservoir, and other wild felids in thirteen states.

Cytauxzoon felis, a protozoan parasite of wild and domestic felids, is the causative agent of cytauxzoonosis in domestic and some exotic felids in the United States. The bobcat (Lynx rufus) is the natural reservoir for this parasite, but other felids such as Florida panthers (Puma concolor coryii) and domestic cats may maintain long-term parasitemias and serve as reservoirs. Experimentally, two tick species, Dermacentor variabilis and Amblyomma americanum, have demonstrated the ability to transmit C. felis. These two tick species have overlapping distributions throughout much of the southeastern United States. The objective of the current study was to determine the distribution and prevalence of C. felis in free-ranging bobcat populations from 13 states including California, Colorado, Florida, Georgia, Kansas, Kentucky, Missouri, North Carolina, North Dakota, Ohio, Oklahoma, South Carolina, and West Virginia. These states were selected because of differential vector presence; D. variabilis is present in each of these states except for the region of Colorado sampled and A. americanum is currently known to be present only in a subset of these states. Blood or spleen samples from 696 bobcats were tested for C. felis infection by a polymerase chain reaction (PCR) assay which targeted the first ribosomal internal transcribed spacer region (ITS-1). Significantly higher prevalences of C. felis were detected from Missouri (79%, n=39), North Carolina (63%, n=8), Oklahoma (60%, n=20), South Carolina (57%, n=7), Kentucky (55%, n=74), Florida (44%, n=45), and Kansas (27%, n=41) compared with Georgia (9%, n=159), North Dakota (2.4%, n=124), Ohio (0%, n=19), West Virginia (0%, n=37), California (0%, n=26), and Colorado (0%, n=67). In addition to bobcats, seven cougars (Puma concolor) from Georgia, Louisiana, and North Dakota and one serval (Leptailurus serval) from Louisiana were tested for C. felis. Only one cougar from Louisiana was PCR positive, which represents the first report of an infected cougar outside of the Florida panther population. These data also indicate that C. felis is present in North Dakota where infection has not been reported in domestic cats. Based on a nonparametric analysis, prevalence rates were significantly higher in states where there are established populations of A. americanum, which supports recent data on the experimental transmission of C. felis by A. americanum and the fact that domestic cat clinical cases are temporally associated with A. americanum activity. Collectively, these data confirm that bobcats are a common reservoir for C. felis and that A. americanum is likely an epidemiologically important vector.

Real-time video recording of food selection by captive white-tailed deer

Abstract Knowledge of animal behavior and resource selection is most accurate when direct observations of animals are made. It is impractical, if not impossible, however, to directly and efficiently observe free-ranging animals for extended periods of time without affecting their behavior. To help address these difficulties, we designed a miniature animal-mounted wireless video camera system that remotely records a portion of the sighting field of white-tailed deer (Odocoileus virginianus). The system consisted of a miniaturized charge-coupled-device (CCD) video camera, a miniaturized UHF transmitter (channel 30 or 42), a light-activated on-off relay circuit, protective plastic housing, a combination VCR/TV, a UHF TV antenna on a 9.1-m mast, and 12 9V lithium-ion DC batteries on a leather neck collar. The real-time color video image was transmitted up to 500 m and recorded on VHS tape. Using this system, we videotaped daytime observations of white-tailed deer food choices for up to 2 weeks. We assessed food choices from 70 hours of video footage from 1 antlered deer recorded during fall 2002 to demonstrate the utility of the technique. Our video system allowed us to monitor detailed food choices without the logistical difficulties present in direct observational studies. This tool could prove useful in studying detailed behavioral observations of captive animals; future development of electronic components could offer applications to free-ranging deer.

The influence of a small sanctuary on survival rates of black bears in North Carolina

Sanctuaries for black bears (Ursus americanus) were established in North Carolina in 1971 to protect breeding females and provide surplus bears for hunting. To test the efficacy of this management technique, we studied survival rates of 51 black bears captured from 1982-89 in and around Harmon Den Bear Sanctuary, North Carolina. We determined the proportion of daily locations that each bear spent off the sanctuary (POFF). We fit a Cox proportional hazard model to these data to determine which combinations of sex, age, and POFF most affected survival. The model selection procedure selected a 2 covariate model of POFF and age as the best model. This model and the mean POFF for each sex and age group indicated adult females had highest survival rates, followed by adult males, subadult females, and subadult males. Harmon Den Bear Sanctuary appears to protect adult females and produces subadult bears for recreational hunting.

Influence of drift and admixture on population structure of American black bears (Ursus americanus) in the Central Interior Highlands, USA, 50 years after translocation

Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears (Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source (AR = 9.11) and significantly lower in the translocated populations (AR = 7.07–7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas.

Survival and Body Condition of Captive-Reared Juvenile Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) Following Translocation to the Wild

We used radiotelemetry and recapture to monitor survival and body condition of 36 captive-reared Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) released at two sites on the North Fork of the White River, Missouri, from May 2008 to August 2009. At the end of our study 16 salamanders were alive, 13 had died, and the fate of seven could not be determined. Captive-reared hellbenders released at a site with densely arranged boulders exhibited approximately 1.5-fold higher annual survival (0.7467; daily survival  =  0.9992 ± 0.0004 95% CI) than hellbenders released at a site where boulders were patchily distributed (0.4816; daily survival  =  0.9980 ± 0.0007 95% CI). When compared to log-transformed length–mass relationships developed for wild hellbenders from the same river in the 1970s, mean body condition of hellbenders at the patchy boulder site was about average at the end of the study (mean residual distance  =  −0.0273 ± 0.0234 SE, n  =  7; range  =  −0.1375–0.0486), while mean body condition of hellbenders at the dense boulder site was above average (mean residual distance  =  0.0423 ± 0.0402 SE; n  =  8; range  =  −0.0374–0.1088). In addition to lower survivorship and body condition, a greater proportion of hellbenders at the patchy site accrued physical abnormalities (6 of 13 vs. 2 of 14), carried leech parasites (9 of 16 vs. 4 of 14), and carried the fungus Batrachochytrium dendrobatidis (3 of 11 vs. 1 of 13). A ‘site only’ model of survival was most supported, though additional supported models suggested increased mass at release may have increased daily survivorship. While more work is needed to determine the impact of translocation on long-term population dynamics of Ozark Hellbenders, our study demonstrated that about half of a translocated population of captive-reared hellbenders can survive while maintaining or increasing in body condition during their first year post-release, given release sites are well selected.

An epizootic of hemorrhagic disease in white-tailed deer in Missouri.

As part of a white-tailed deer (Odocoileus virginianus) survival study in Missouri (USA) we were actively monitoring 97 radio-collared deer when 8 (8%) died. This mortality, which occurred from 20 August to 23 September 1996, consisted of five adult females, two yearling females and one yearling male. Based on the seasonality of this mortality and the isolation of epizootic hemorrhagic disease virus (EHDV) serotype 2 from one of these animals, we believe that these losses resulted from an epizootic of hemorrhagic disease. The remains of five unmarked deer that may have died from HD also were found on the study area during this same period. During the fall following this mortality, we tested serum from 96 deer taken by hunters in the immediate area. Fifteen (16%) were positive for EHDV or bluetongue virus (BTV) antibodies as determined by agar gel immunodiffusion tests. Serum neutralization test results indicated that previous infections were caused by EHDV virus serotype 2. Based on these data, and assuming that there was no prior exposure to EHDV serotype 2 in this population, the exposure rate for this epizootic was 24% of which 8% died. We noted hoof interruptions in only two of the 96 deer sampled. During this mortality event, the Missouri Department of Conservation received no reports of dead deer, and without the radio-monitored animals the event would have been undetected.

Historic occurrence of the amphibian chytrid ­fungus Batrachochytrium dendrobatidis in ­hellbender Cryptobranchus alleganiensis ­populations from Missouri

The pathogenic fungus Batrachochytrium dendrobatidis (Bd) was recently detected in Missouri hellbender Cryptobranchus alleganiensis populations that have declined precipitously for unclear reasons. The objective of this study was to determine whether Bd occurred historically in Missouri hellbender populations or is a relatively novel occurrence. Epidermal tissue was removed from 216 archived hellbenders collected from 7 Missouri streams between 1896 and 1994. Histological techniques and an immunoperoxidase stain were used to confirm historic occurrence of Bd infection in hellbenders from the North Fork of the White (1969, 1973, 1975), Meramec (1975, 1986), Big Piney (1986), and Current rivers (1988). Bd was not detected in hellbenders from the Niangua, Gasconade or Eleven Point rivers. The study detected no evidence for endemism of Bd in Missouri hellbender populations prior to 1969, despite the fact that nearly one third of the hellbenders sampled were collected earlier. Our findings are consistent with the hypothesis that Bd is a non-endemic pathogen in North America that was introduced in the second half of the twentieth century.

Trap Array Configuration Influences Estimates and Precision of Black Bear Density and Abundance

Spatial capture-recapture (SCR) models have advanced our ability to estimate population density for wide ranging animals by explicitly incorporating individual movement. Though these models are more robust to various spatial sampling designs, few studies have empirically tested different large-scale trap configurations using SCR models. We investigated how extent of trap coverage and trap spacing affects precision and accuracy of SCR parameters, implementing models using the R package secr. We tested two trapping scenarios, one spatially extensive and one intensive, using black bear (Ursus americanus) DNA data from hair snare arrays in south-central Missouri, USA. We also examined the influence that adding a second, lower barbed-wire strand to snares had on quantity and spatial distribution of detections. We simulated trapping data to test bias in density estimates of each configuration under a range of density and detection parameter values. Field data showed that using multiple arrays with intensive snare coverage produced more detections of more individuals than extensive coverage. Consequently, density and detection parameters were more precise for the intensive design. Density was estimated as 1.7 bears per 100 km2 and was 5.5 times greater than that under extensive sampling. Abundance was 279 (95% CI = 193–406) bears in the 16,812 km2 study area. Excluding detections from the lower strand resulted in the loss of 35 detections, 14 unique bears, and the largest recorded movement between snares. All simulations showed low bias for density under both configurations. Results demonstrated that in low density populations with non-uniform distribution of population density, optimizing the tradeoff among snare spacing, coverage, and sample size is of critical importance to estimating parameters with high precision and accuracy. With limited resources, allocating available traps to multiple arrays with intensive trap spacing increased the amount of information needed to inform parameters with high precision.