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Joseph D. Clark

Publications and source records attributed to Joseph D. Clark.

71 records · Page 4Linked to original sources
USGS2003

Estimating black bear population density and genetic diversity at Tensas River, Louisiana using microsatellite DNA markers

The Recovery Plan for the federally threatened Louisiana black bear ( Ursus americanus luteolus ) mandates that remnant populations be estimated and monitored. In 1999 we obtained genetic material with barbed-wire hair traps to estimate bear population size and genetic diversity at the 329-km 2 Tensas River Tract, Louisiana. We constructed and monitored 122 hair traps, which produced 1,939 hair samples. Of those, we randomly selected 116 subsamples for genetic analysis and used up to 12 microsatellite DNA markers to obtain multilocus genotypes for 58 individuals. We used Program CAPTURE to compute estimates of population size using multiple mark-recapture models. The area of study was almost entirely circumscribed by agricultural land, thus the population was geographically closed. Also, study-area boundaries were biologically discreet, enabling us to accurately estimate population density. Using model Chao M h to account for possible effects of individual heterogeneity in capture probabilities, we estimated the population size to be 119 (SE=29.4) bears, or 0.36 bears/km 2 . We were forced to examine a substantial number of loci to differentiate between some individuals because of low genetic variation. Despite the probable introduction of genes from Minnesota bears in the 1960s, the isolated population at Tensas exhibited characteristics consistent with inbreeding and genetic drift. Consequently, the effective population size at Tensas may be as few as 32, which warrants continued monitoring or possibly genetic augmentation.

Louisiana↗
USGS2003

Predicting rare plant occurrence in Great Smoky Mountains National Park, USA

We investigated the applicability of biometric habitat modeling to rare plant inventory and conservation by developing and field testing a geographically explicit model for Cardamine clematitis Shuttleworth ex A. Gray (mountain bittercress), an endemic plant of the southern Blue Ridge Mountains, USA. For each of 187 confirmed coordinates for C. clematitis in Great Smoky Mountains National Park, 13 habitat variables were measured with a geographic information system. These data were used to calculate Mahalanobis distances for each 30-m x 30-m pixel within the study area; small values of Mahalanobis distance represented site conditions similar to those of known locations of C. clematitis , whereas larger distance values represented dissimilar conditions. Following model development, we tested model performance by sampling 120 randomly distributed plots for C. clematitis presence. Logistic regression showed that Mahalanobis distance values were strongly related to C. clematitis occurrence (P = 0.039). Overall, 75% of all known occurrences of C. clematitis had associated Mahalanobis distance values below 17.7, and 95% of all occurrences were below 33.8; the median Mahalanobis distance value for the study area as a whole was 40.0. A habitat suitability cutoff value was defined which identified roughly 23,640 ha (19.5% of the study area) as suitable habitat. Although the model successfully predicted species absence in test plots with high Mahalanobis distance values, many sites with low values did not contain C. clematitis . Only 16.2% of test plots below the habitat suitability cutoff contained C. clematitis . The absence of C. clematitis from sites with low Mahalanobis distance values (low specificity) is not necessarily indicative of a poor model; metapopulation processes (e.g., recolonizations, local extinctions) have been shown to play a major role in presence or absence of many plant species. That may be partially the case with our model as evidenced by a relationship between C. clematitis presence and habitat patch size.

North Carolina, Tennesse↗
USGS2002

Responses of Florida panthers to recreational deer and hog hunting

Big Cypress National Preserve constitutes approximately one-third of the range of the endangered Florida panther ( Puma concolor coryi ). Because recreational hunting is allowed in Big Cypress National Preserve, we examined 8 response variables (activity rates, movement rates, predation success, home-range size, home-range shifts, proximity to off-road vehicle trails, use of areas with concentrated human activity, and habitat selection) to evaluate how Florida panthers respond to human activity associated with deer and hog hunting. Data consisted of panther radiolocations collected since 1981 by the Florida Fish and Wildlife Conservation Commission and the National Park Service, which we augmented with radiolocations and activity monitoring from 1994 to 1998. A split-plot (treatment and control) study design with repeated measures of the variables for each panther taken before, during, and after the hunting season was used. We did not detect responses to hunting for variables most directly related to panther energy intake or expenditure (i.e., activity rates, movement rates, predation success of females; P >0.10). However, panthers reduced their use of Bear Island ( P =0.021), an area of concentrated human activity, and were found farther from off-road vehicle trails ( P ≤0.001) during the hunting season, which was indicative of a reaction to human disturbance. Whereas the reaction to human activity on off-road vehicle trails probably has minor biological implications and may be linked to prey behavior, the decreased use of Bear Island is most likely a direct reaction to human activity and resulted in increased use of adjacent private lands. Future habitat loss on those private lands could exacerbate the negative consequences of this response by panthers.

Florida↗
USGS2002

Evaluation of 2-soft-release techniques to reintroduce black bears

Black bear ( Ursus americanus ) were extirpated from most of their range by the early 1900s by habitat destruction and unregulated hunting. Since then, bear habitat has recovered in many areas, but isolation may prevent natural recolonization. Black bear translocations often have limited success because of high mortality rates and low site fidelity. We tested 2 reintroduction techniques designed to overcome those problems. The first technique used a winter release whereby pre- or post-parturient female bears were removed from their dens and placed in new dens at the release area. The second technique involved translocating female bears to the reintroduction area during summer and holding them in pens for a 2-week acclimation period before release. We translocated 8 female bears with cubs with the winter-release technique and 6 female with the summer-release technique. After release, total distance moved, net distance moved, mean daily distance moved, and circuity for winter-released bears (x̄=18.3 km, 7.1 km, 1.4 km, and 0.36, respectively) were less than summer-released bears (x̄=97.6, 63.4 km 5.1 km, and 0.74; P =0.010, 0.040, 0.019, and 0.038, respectively). Also, survival of winter-released bears (0.88) was greater than that for summer-released bears (0.2, P=0.001). Population modeling indicated that the least one additional stocking of 6 adult females with 12 cubs would greatly increase chances of population reestablishment. the winter-release technique has distinct advantages over the summer-release technique, limiting post-release movements and increasing survival of translocated bears.

Kentucky, Tennessee↗
USGS2002

Bear reintroduction: Lessons and challenges

Reintroduction is defined as an attempt to establish a species in an area that was once part of its historical range, but from which it has been extirpated or become extinct. Historically, one of the most successful programs was the reintroduction of 254 American black bears ( Ursus americanus ) from Minnesota to the Interior Highlands of Arkansas in the 1960s; that population has grown to >2,500 today. More recent efforts have involved fewer but better monitored animals and have sometimes employed techniques to improve site fidelity and survival. In Pennsylvania, for example, pregnant female American black bears were successfully translocated from winter dens, the premise being that the adult females would be less likely to return because of the presence of young cubs. That winter-release technique was compared to summer trapping and release in Tennessee; winter releases resulted in greater survival and reduced post-release movements. Homing has not been a problem for small numbers of brown bears ( Ursus arctos ) reintroduced to the Cabinet-Yaak ecosystem in Montana and Idaho and to the mountains of Austria and France. Reintroduction success appears to be correlated with translocation distance and is greater for subadults and females. As with any small population, reintroduced bear populations are susceptible to environmental variation and stochastic demographic and genetic processes. Although managers have focused on these biological barriers, sociopolitical impediments to bear reintroduction are more difficult to overcome. Poor public acceptance and understanding of bears are the main reasons some reintroduction programs have been derailed. Consequently, the public should be involved in the reintroduction process from the outset; overcoming negative public perceptions about bear reintroduction will be our greatest challenge.

Ursus↗
USGS2001

Florida panther habitat use response to prescribed fire

The Florida panther ( Puma concolor coryi ) is one of the most endangered mammals in the world, with only 30-50 adults surviving in and around Florida Panther National Wildlife Refuge and the adjacent Big Cypress National Preserve. Managers at these areas conduct annual prescribed burns in pine ( Pinus sp.) as a cost-effective method of managing wildlife habitat. Our objectives were to determine if temporal and spatial relationships existed between prescribed fire an panther use of pine. to accomplish this, we paired fire-event data from the Refuge an the Preserve with panther radiolocations collected between 1989 and 1998, determined the time that had elapsed since burning had occurred in management units associated with the radiolocations, and generated a frequency distribution based on those times. We then generated ant expected frequency distribution, based on random use relative to time since burning. This analysis revealed that panther use of burned pine habitats was greatest during the first year after a management unit was burned. Also, compositional analysis indicated that panthers were more likely to position their home ranges in areas that contained pine. We conclude that prescribed burning is important to panther ecology. We suggest that panthers were attracted to <1-year-old burns because of white-tailed deer ( Odocoileus virginianus ) and other prey responses to vegetation and structural changed caused by the prescribed fires. The strong selection for stands burned within 1 year is a persuasive indication that it is the burning in pine, rather than the pine per se, that most influenced habitat use. Before burning rotation lengths are reduced, however, we suggest managers determine effects of shorter burning intervals on vegetation composition and evaluate the landscape-scale changes that would result.

Florida↗
USGS2000

Predicting red wolf release success in the southeastern United States

Although the red wolf ( Canis rufus ) was once found throughout the southeastern United States, indiscriminate killing and habitat destruction reduced its range to a small section of coastal Texas and Louisiana. Wolves trapped from 1973 to 1980 were taken to establish a captive breeding program that was used to repatriate 2 mainland and 3 island red wolf populations. We collected data from 320 red wolf releases in these areas and classified each as a success or failure based on survival and reproductive criteria, and whether recaptures were necessary to resolve conflicts with humans. We evaluated the relations between release success and conditions at the release sites, characteristics of released wolves, and release procedures. Although <44% of the variation in release success was explained, model performance based on jackknife tests indicated a 72-80% correct prediction rate for the 4 operational models we developed. The models indicated that success was associated with human influences on the landscape and the level of wolf habituation to humans prior to release. We applied the models to 31 prospective areas for wolf repatriation and calculated an index of release success for each area. Decision-makers can use these models to objectively rank prospective release areas and compare strengths and weaknesses of each.

Journal of Wildlife Management↗
USGS1999

Predicting mountain lion activity using radiocollars equipped with mercury tip-sensors

Radiotelemetry collars with tip-sensors have long been used to monitor wildlife activity. However, comparatively few researchers have tested the reliability of the technique on the species being studied. To evaluate the efficacy of using tip-sensors to assess mountain lion ( Puma concolor ) activity, we radiocollared 2 hand-reared mountain lions and simultaneously recorded their behavior and the associated telemetry signal characteristics. We noted both the number of pulse-rate changes and the percentage of time the transmitter emitted a fast pulse rate (i.e., head up) within sampling intervals ranging from 1-5 minutes. Based on 27 hours of observations, we were able to correctly distinguish between active and inactive behaviors >93% of the time using a logistic regression model. We present several models to predict activity of mountain lions; the selection of which to us would depend on study objectives and logistics. Our results indicate that field protocols that use only pulse-rate changes to indicate activity can lead to significant classification errors.

Florida↗
USGS1994

Black bears in Arkansas: Characteristics of a successful translocation

In 1958, the Arkansas Game and Fish Commission began translocating black bears ( Ursus americanus ) from Minnesota to the Interior Highlands (Ozark and Ouachita mountains) of Arkansas where bears had been extirpated early in this century. This project continued for 11 years with little public imput, during which time an estimated 254 bears were released. We estimate there are now >2,500 bears in the Interior Highlands of Arkansas, Missouri, and Oklahoma, making it one of the most successful translocations of a Carnivora. Factors that contributed to the success include use of wild-captured animals, elimination of major factors associated with extirpation, release into prime habitats within the former range, multiple release sites, release of 20&ndash;40 animals/year for eight years, and release of mostly males prior to release of mostly females. Studies on two allopatric populations demonstrate that they are now diverging in some demographic characteristics, including litter size, cub survivorship, and adult sex-ratio. Translocation of black bears to the Interior Highlands is successful in terms of numbers of animals, but it will not be truly successful until people accept black bears as part of the regional fauna. To that end, those associated with management and research of bears in Arkansas are now focussing on public education and control of nuisance bears.

Arkansas↗
USGS1994

A demographic comparison of two black bear populations in the Interior Highlands of Arkansas

The Ozark and Ouachita mountain regions of western Arkansas, collectively known as the Interior Highlands, historically supported large numbers of black bears ( Ursus americanus ). Indiscriminate killing of bears by early settlers and subsequent habitat reductions due to extensive logging and changes in land use resulted in their decline (Smith et al. 1991). By the late 1940's, bears had been extirpated from both regions (Holder 1951). Between 1958 and 1968, Arkansa Game and Fish Commission (ACFC) Officials trapped 254 black bears in northern Minnesota and Manitoba, Canada and released them in the Interior Highlands (Rogers 1973, Smith et al. 1991d). Since then, bear numbers have dramatically increased, making the Arkansas reintroduction the most successful attempted for black bears (Smith et al. 1991). Hunts have been conducted each autumn or winter since 1980. Because little was known about bear demographics and sustainable harvest in the Interior Highlands, however, hunting regulations have been restrictive with 5-31 bears harvested/year (J.D. Clark, AGFC Annu. Harvest Rep., 1980-1988). Bears now range throughout the Ozark Mountains and Ouachita Mountains, but these regional populations are allopatric, separated by the Arkansas River Valley and Interstate 40 (J.D. Clark, unpubl. data). Past reintroduction strategies and harvest levels differed between the 2 regions, with more intensive restocking and hunting in the Ozark region. Habitat also differs with the Ozark Mountains primarily oak-hickory ( Quercus spp.- Carya spp.) upland forest compared to pine ( Pinus spp.) and mixed pine-hardwood forest in the Ouachita Mountais (Smith 1989). Because habitat quality has been shown to be the major factor affecting black bear productivity (Rogers 1976, Bunnell and Tait 1981, Elowe and Dodge 1989) and bear populations are susceptible to overharvest, our objectives were to: 1) estimate population growth and sustainable yield for populations in both regions and 2) determine whether different environmental conditions in the 2 regions resulted in differences in demographic parameters.

Arkansas↗
USGS1994

Black bear habitat use in relation to food availability in the Interior Highlands of Arkansas

A black bear ( Ursus americanus ) food value index (FVI) was developed and calculated for forest cover type classifications on Ozark Mountain (White Rock) and Ouachita Mountain (Dry Creek) study areas in western Arkansas. FVIs are estimates of bear food production capabilities of the major forest cover types and were calculated using percent cover, mean fruit production scorings, and the dietary percentage of each major plant food species as variables. Goodness-of-fit analyses were used to determine use of forest cover types by 23 radio-collared female bears. Habitat selection by forest cover type was not detected on White Rock but was detected on Dry Creek. Use of habitats on Dry Creek appeared to be related to food production with the exception of regeneration areas, which were used less than expected but had a high FVI ranking. In general, pine cover types had low FVI rankings and were used less than expected by bears. Forest management implications are discussed.

Arkansas↗
USGS1993

Multivariate model of female black bear habitat use for a Geographic Information System

Simple univariate statistical techniques may not adequately assess the multidimensional nature of habitats used by wildlife. Thus, we developed a multivariate method to model habitat-use potential using a set of female black bear ( Ursus americanus ) radio locations and habitat data consisting of forest cover type, elevation, slope, aspect, distance to roads, distance to streams, and forest cover type diversity score in the Ozark Mountains of Arkansas. The model is based on the Mahalanobis distance statistic coupled with Geographic Information System (GIS) technology. That statistic is a measure of dissimilarity and represents a standardized squared distance between a set of sample variates and an ideal based on the mean of variates associated with animal observations. Calculations were made with the GIS to produce a map containing Mahalanobis distance values within each cell on a 60- &times; 60-m grid. The model identified areas of high habitat use potential that could not otherwise be identified by independent perusal of any single map layer. This technique avoids many pitfalls that commonly affect typical multivariate analyses of habitat use and is a useful tool for habitat manipulation or mitigation to favor terrestrial vertebrates that use habitats on a landscape scale.

Arkansas↗
USGS1987

Arkansas black bear hunter survey

Questionnaires were mailed to black bear ( Ursus americanus ) hunters in Arkansas following the 1980-84 bear seasons to determine participation, hunter success, and number of bears observed by hunters. Man-days of hunting to harvest a bear ranged from 148 to 671 and hunter success ranged from 0.4% to 2.2%. With the exception of 1980, number of permits issued, man-days of bear hunting, and bears harvested appear affected by hunting permit cost.

Ursus↗