Dave Onorato

Detection of Predator Presence at Elk Mortality Sites Using mtDNA Analysis of Hair and Scat Samples

Abstract The identification of carnivores responsible for preying on wild or domestic ungulates often is of interest to wildlife managers. Typically, field personnel collect a variety of data at mortality sites including scat or hair samples that may have been deposited by the predator. We compared mitochondrial DNA (mtDNA) analysis of hair and scat samples (n = 122) collected at elk (Cervus elaphus) mortality sites between 1997 and 2004 in north-central Idaho, USA, with field identification of carnivore presence. We amplified mtDNA from samples via a 2-step process involving an initial screening for American black bears (Ursus americanus), brown bears (Ursus arctos), and gray wolves (Canis lupus) using a length variation in the 5′ hypervariable section of the control region. Samples that failed the first screening subsequently were analyzed using conserved mtDNA primers that amplify a wide array of vertebrates. Species identification success rate was high (88.5%) and established the presence of 3 predators at elk mortality sites including black bears (55.7%), cougars (Puma concolor; 27.9%), and coyotes (Canis latrans; 6.6%). Attempts at hair and scat identification by field personnel were correct for 58% of hair samples and 79% of fecal samples. Results from these analyses demonstrate the merits of combining field mortality assessments with mtDNA species identification to aid wildlife managers in more accurately pinpointing predators involved in either predation or depredation events.

Florida Panther Habitat Selection Analysis of Concurrent GPS and VHF Telemetry Data

Abstract Florida panthers (Puma concolor coryi) are listed as an endangered subspecies in the United States and they exist in a single Florida population with <100 individuals; all known reproduction occurs south of Lake Okeechobee. Habitat loss is the biggest threat to this small population and previous studies of habitat selection have relied on very high frequency (VHF) telemetry data collected almost exclusively during diurnal periods. We investigated habitat selection of 12 panthers in the northern portion of the breeding range using 1) Global Positioning System (GPS) telemetry data collected during nocturnal and diurnal periods and 2) VHF telemetry data collected only during diurnal periods. Analysis of both types of telemetry data yielded similar results as panthers selected upland (P < 0.001) and wetland (P < 0.001) forested habitat types. Our results indicated that forests are the habitats selected by panthers and generally support the current United States Fish and Wildlife Service panther habitat ranking system. We suggest that future studies with greater numbers of panthers should investigate panther habitat selection using GPS telemetry data collected throughout the range of the Florida panther and with location attempts scheduled more evenly across the diel period. Global Positioning System radiocollars were effective at obtaining previously unavailable nocturnal telemetry data on panthers; however, we recommend that panther researchers continue to collect VHF telemetry data until acquisition rates and durability of GPS collars improve.

Is there a single best estimator? Selection of home range estimators using area-under-the-curve

BackgroundGlobal positioning system (GPS) technology for monitoring home range and movements of wildlife has resulted in prohibitively large sample sizes of locations for traditional estimators of home range. We used area-under-the-curve to explore the fit of 8 estimators of home range to data collected with both GPS and concurrent very high frequency (VHF) technology on a terrestrial mammal, the Florida panther Puma concolor coryi, to evaluate recently developed and traditional estimators.ResultsArea-under-the-curve was the highest for Florida panthers equipped with Global Positioning System (GPS) technology compared to VHF technology. For our study animal, estimators of home range that incorporated a temporal component to estimation performed better than traditional first- and second-generation estimators.ConclusionsComparisons of fit of home range contours with locations collected would suggest that use of VHF technology is not as accurate as GPS technology to estimate size of home range for large mammals. Estimators of home range collected with GPS technology performed better than those estimated with VHF technology regardless of estimator used. Furthermore, estimators that incorporate a temporal component (third-generation estimators) appeared to be the most reliable regardless of whether kernel-based or Brownian bridge-based algorithms were used and in comparison to first- and second-generation estimators. We defined third-generation estimators of home range as any estimator that incorporates time, space, animal-specific parameters, and habitat. Such estimators would include movement-based kernel density, Brownian bridge movement models, and dynamic Brownian bridge movement models among others that have yet to be evaluated.

Strategically Locating Wildlife Crossing Structures for Florida Panthers Using Maximal Covering Approaches

Crossing structures are an effective method for mitigating habitat fragmentation and reducing wildlife-vehicle collisions, although high construction costs limit the number that can be implemented in practice. Therefore, optimizing the placement of crossing structures in road networks is suggested as a strategic conservation planning method. This research explores two approaches for using the maximal covering location problem (MCLP) to determine optimal sites to install new wildlife crossing structures. The first approach is based on records of traffic mortality, while the second uses animal tracking data for the species of interest. The objective of the first is to cover the maximum number of collision sites, given a specified number of proposed structures to build, while the second covers as many animal tracking locations as possible under a similar scenario. These two approaches were used to locate potential wildlife crossing structures for endangered Florida panthers (Puma concolor coryi) in Collier, Lee, and Hendry Counties, Florida, a population whose survival is threatened by excessive traffic mortality. Historical traffic mortality records and an extensive radio-tracking dataset were used in the analyses. Although the two approaches largely select different sites for crossing structures, both models highlight key locations in the landscape where these structures can remedy traffic mortality and habitat fragmentation. These applications demonstrate how the MCLP can serve as a useful conservation planning tool when traffic mortality or animal tracking data are available to researchers.

Endangered Florida panther population size determined from public reports of motor vehicle collision mortalities

Summary 1. Reliably estimating the abundance of rare or elusive animals is notoriously difficult. An archetypical example is the endangered Florida panther, whose conservation status is intrinsically linked to population size, but for which reliable abundance information is lacking across its range. This is due not only to the inherent difficulty of sampling a rare and elusive species over a large geographic area, but also because of restricted scientific access to private land. 2. Human interactions with wildlife are a regular occurrence, and interactions with non-scientists constitute an important and underutilized source of information about species distribution and abundance. For example, motor vehicle collisions with Florida panthers are recurrent on the vast network of roads within the public and private lands comprising its range in southern Florida, USA. 3. Capitalizing on a tendency for the public to report collisions with species of concern to wildlife officials, we describe a novel methodology using public reports along with routine telemetry monitoring data to produce the first statistically defensible population estimates for the Florida panther across its entire breeding range. In essence, our approach uses traffic volume and road density to estimate the probability of motor vehicle collision mortality from telemetered animals and models counts reported by the public accordingly. 4. Despite low motor vehicle collision mortality probabilities, our methodology achieved abundance estimates of reasonable precision (29% CV) that was similar to that of previous panther studies using conventional approaches on much smaller study areas. While recovery criteria require establishment of three distinct populations of 240 Florida panthers, we found this single population may never have exceeded 150 individuals from 2000 to 2012. 5. Synthesis and applications. By extracting critical demographic information from underutilized aspects of human–wildlife ecology, our citizen-based approach can cost less than conventional alternatives and could conceivably be used for long-term population monitoring of other species over broad geographic areas, for example from reports of avian wind farm collisions, beached whales or marine mammal boat strikes. An additional benefit is that it can be applied to historical data sets of carcass recovery programmes, in our case permitting abundance estimation over a 13-year period.

Genetic Assessment of Paternity and Relatedness in a Managed Population of Cougars

ABSTRACT Understanding the social dynamics of large carnivores is critical to effective conservation and management planning. We made the first attempt to delineate both paternity and relatedness for a population of cougar (Puma concolor) using microsatellite data. We analyzed a long-term genetic dataset collected from a hunted population in the Garnet Mountains of western Montana. We assigned paternity for 62.5% of litters sampled using both exclusion and likelihood analyses. Attempts at reconstructing unsampled paternal genotypes resulted in delineating possible sires for 8 more litters. Sires were on average younger than reported for males involved in pairings assessed via field data in other cougar populations. Although most mating pairs were unrelated, 5 of 17 pairings involved cougars with levels of relatedness corresponding to half-sibling and full-sibling or parent offspring relationship (r = 0.215–0.575). Relatedness among adult and subadult males was higher than relatedness levels among adult and subadult females. Relatedness among males in the Garnet population differed from patterns hypothesized to occur under male-biased dispersal theories for cougars. The long-term impact of the turnover of resident cougars in hunted populations is still unclear and warrants additional research. Our results highlight the utility of monitoring cougar demographic parameters using a combination of genetic and field data that in turn may assist managers with determining cougar harvest quotas or strategies, harvest seasons, sustainable harvest, and the appropriate management level of cougar populations.

Winter ecology of American black bears in a desert montane island

Abstract American black bears (Ursus americanus) have recolonized western Texas following extirpation in the mid-1900s. Knowledge of winter ecology of black bears is important for conservation and management because denning, parturition, and early cub development occur during this period. We monitored 13 radiocollared black bears for 22 den-years in Big Bend National Park (BBNP) during 1998–2003. All pregnant females (n=6), 2 females with yearlings, 7 subadults, and 1 adult male denned. Three females with yearlings remained active during winter 1998–1999. We located 4 cave dens, 5 ground dens, and 6 rock-pile dens. Volume and elevation of den sites averaged 2.00 m3 (SD=1.51) and 1,800 m (SD=346), respectively. Mean (±SD) dates of den entrance and emergence for 5 pregnant females were 30 December±17 days and 27 April±21 days, respectively, producing a mean denning period of 118±29 days. Pregnant females exited dens later (P= 0.003) and denned longer (P=0.02) than solitary females and males. Black bears in western Texas used den sites located in higher elevations that were remote and highly defensible. A den-habitat model described less than 56 km2 of suitable denning habitat within and bordering BBNP. Resource managers should reduce visitor and management activities in and around potential denning areas during winter.

High prevalence of Trichinella pseudospiralis in Florida panthers (Puma concolor coryi)

BackgroundParasites of the genus Trichinella are zoonotic nematodes common in carnivores throughout the world. We determined the prevalence and species of Trichinella infections in Florida panthers (Puma concolor coryi).MethodsTongues from Florida panthers were collected at necropsy and examined by pepsin-HCl artificial digestion for infection with Trichinella spp. DNA was extracted from larvae and multiplex PCR using Trichinella species-specific primers was used to genotype the worms.ResultsTrichinella spp. larvae were detected in 24 of 112 (21.4%; 14.6%–30.3%) panthers. Sixteen of the panthers (14.3%) were infected with T. pseudospiralis, 1 (0.9%) was infected with T. spiralis, and 2 (1.8%) had mixed infections of T. pseudospiralis and T. spiralis. Trichinella spp. larvae from 5 panthers were not identified at the species level due to degraded DNA.ConclusionsThis is the highest prevalence of T. pseudospiralis detected in North America up to now and suggests the Florida panther is a key mammalian reservoir of this parasite in southern Florida. Trichinella pseudospiralis can infect both mammals and birds indicating the source of infection for Florida panthers could be broader than believed; however, birds represent a small percentage (0.01%) of the cat’s diet. Since wild pigs (Sus scrofa) can be parasitized by both T. pseudospiralis and T. spiralis and these swine can comprise a large portion (~40%) of a panther’s diet in Florida, we believe that Florida panthers acquired these zoonotic parasites from feeding on wild pigs.

Growth in Body Length and Mass of the Florida Panther: An Evaluation of Different Models and Sexual Size Dimorphism

Abstract Knowledge of growth in body dimension and mass is important to understanding fundamental elements of wildlife biology and ecology. We evaluated five classical growth models (Gompertz, Logistic, Monomolecular, Richards, and von Bertalanffy) in describing body length and mass growth curves as a function of age to determine which best fit wild Puma concolor coryi (Florida Panther). When used for inferences on body length and mass growth curves of both genders, the von Bertalanffy function proved to be the best-fitting theoretical equation to our data set because it used the fewest parameters derived directly from metabolic laws, had lowest residual standard deviation of data points about fitted model, with lower Akaike Information Criterion value, and largest Akaike weight. The von Bertalanffy model estimated that male asymptotic body length was 9.4% longer and mass was 33.2% heavier than for females. Both genders grew in body mass for a longer duration than length. Male-biased sexual size dimorphism develops in part because males grew faster and for a more prolonged period. Our results should prove useful in future studies of Panther energetics, reproduction, and in developing conservation and management policies for this species.

Assessing impacts of intrinsic and extrinsic factors on Florida panther movements

Movement patterns can influence an animals ability to secure food, find mates, and avoid enemies, potentially affecting individual fitness. We studied movement patterns of 10 male and 3 female endangered Florida panthers (Puma concolor coryi) using location data collected from a long-term (2005–2012) GPS collar study. Males traveled faster and covered longer daily distances than females during both the wet and dry seasons (wet:dry—males 289:372 m/h and 4,616:6,701 m; females 186:280 m/h and 2,629:5,239 m). Panthers occupying higherselected habitat traveled faster, but with shorter daily movement distances in comparison to habitats that were less frequently selected. An index of risk (derived using traffic volume and road density) that was linked to habitat predicted to be avoided by panthers was associated with reduced daily movement distances. Our results suggest that Florida panthers alter their movement patterns in response to environmental change and anthropogenic disturbances.