Frank T. van Manen

Identifying Suitable Sites for Florida Panther Reintroduction

Abstract A major objective of the 1995 Florida Panther (Puma concolor coryi) Recovery Plan is the establishment of 2 additional panther populations within the historic range. Our goal was to identify prospective sites for Florida panther reintroduction within the historic range based on quantitative landscape assessments. First, we delineated 86 panther home ranges using telemetry data collected from 1981 to 2001 in south Florida to develop a Mahalanobis distance (D2) habitat model, using 4 anthropogenic variables and 3 landscape variables mapped at a 500-m resolution. From that analysis, we identified 9 potential reintroduction sites of sufficient size to support a panther population. We then developed a similar D2 model at a higher spatial resolution to quantify the area of favorable panther habitat at each site. To address potential for the population to expand, we calculated the amount of favorable habitat adjacent to each prospective reintroduction site within a range of dispersal distances of female panthers. We then added those totals to the contiguous patches to estimate the total amount of effective panther habitat at each site. Finally, we developed an expert-assisted model to rank and incorporate potentially important habitat variables that were not appropriate for our empirical analysis (e.g., area of public lands, livestock density). Anthropogenic factors heavily influenced both the landscape and the expert-assisted models. Of the 9 areas we identified, the Okefenokee National Wildlife Refuge, Ozark National Forest, and Felsenthal National Wildlife Refuge regions had the highest combination of effective habitat area and expert opinion scores. Sensitivity analyses indicated that variability among key model parameters did not affect the high ranking of those sites. Those sites should be considered as starting points for the field evaluation of potential reintroduction sites.

Identifying Habitat Linkages for American Black Bears in North Carolina, USA

Abstract Understanding landscape structure and the role of habitat linkages is important to managing wildlife populations in fragmented landscapes. We present a data-based method for identifying local- and regional-scale habitat linkages for American black bears (Ursus americanus) on the Albemarle-Pamlico Peninsula of North Carolina, USA. We used weights-of-evidence, a discrete multivariate technique for combining spatial data, to make predictions about bear habitat use from 1,771 telemetry locations on 2 study areas (n = 35 bears). The model included 3 variables measured at a 0.2-km2 scale: forest cohesion, forest diversity, and forest–agriculture edge density, adequately describing important habitat characteristics for bears on our study area. We used 2 categories of unique habitat conditions to delineate favorable bear habitat, which correctly classified 79.5% of the bear locations in a 10-fold model validation. Forest cohesion and forest–agriculture edge density were the most powerful predictors of black bear habitat use. We used predicted probabilities of bear occurrence from the model to delineate habitat linkages among local and regional areas where bear densities were relatively high. Our models clearly identified 2 of the 3 sites previously recommended for wildlife underpasses on a new, 4-lane highway in the study area. Our approach yielded insights into how landscape metrics can be integrated to identify linkages suitable as habitat and dispersal routes.

BAIT STATIONS, HARD MAST, AND BLACK BEAR POPULATION GROWTH IN GREAT SMOKY MOUNTAINS NATIONAL PARK

Abstract Bait-station surveys are used by wildlife managers as an index to American black bear (Ursus americanus) population abundance, but the relationship is not well established. Hard mast surveys are similarly used to assess annual black bear food availability, which may affect mortality and natality rates. We used data collected in Great Smoky Mountains National Park (GSMNP) from 1989 to 2003 to determine whether changes in the bait-station index (ΔBSI) were associated with estimated rates of bear population growth (λ) and whether hard mast production was related to bear visitation to baits. We also evaluated whether hard mast production from previous years was related to λ. Estimates of λ were based on analysis of capture–recapture data with the Pradel temporal symmetry estimator. Using the Akaikes Information Criterion (AIC), our analysis revealed no direct relationship between Δ BSI and λ. A simulation analysis indicated that our data were adequate to detect a relationship had one existed. Model fit was marginally improved when we added total oak mast production of the previous year as an interaction term suggesting that the BSI was confounded with environmental variables. Consequently, the utility of the bait-station survey as a population monitoring technique is questionable at the spatial and temporal scales we studied. Mast survey data, however, were valuable covariates of λ. Population growth for a given year was negatively related to oak mast production 4 and 5 years prior. That finding supported our hypothesis that mast failures can trigger reproductive synchrony, which may not be evident from the trapped sample until years later.

Relationships between Asiatic black bear kills and depredation costs in Nagano Prefecture, Japan

Abstract Over 1,000 Asiatic black bears (Ursus thibetanus) are killed each year in Japan to control depredation activity. Our objective was to determine if killing bears reduces depredation costs. We focused our study on Nagano Prefecture, where 2,562 nuisance bears were reported killed and where reported depredation cost exceeded ¥1,430 million between 1979 and 1999. We used mixed models with repeated measures to determine if annual depredation costs were associated with the number of bears killed. Our data set included 15 years (1985–99) of kill and cost data for 122 municipal jurisdictions within 10 regions. We performed analyses at the regional level based on combined harvest and nuisance kill data, and at the municipal level based only on nuisance kill data. We classified the number of kills into 3 classes (low, medium, high). Analyses were repeated using prior-year kills to examine whether a possible time-lag existed. Annual depredation costs were positively associated with the kill data at the regional level (F = 5.51; 2, 72.3 df; P = 0.006) during the same year. However, we observed no association based on prior-year kill data (F = 0.96; 2, 65.1 df; P = 0.390), suggesting that depredation costs and bear kills are a function of nuisance bear numbers rather than reflecting a causal relationship between the 2 measures. Nuisance bear numbers may in turn be affected either by the availability of natural foods or by general population trends. At the municipal level, depredation costs were not associated with the number of nuisance bears killed during the same year (F = 1.36; 2, 466 df; P = 0.258) or the prior year (F = 0.42; 2, 459 df; P = 0.656). Our results suggest that systematically killing Asiatic bears may not be an effective tool for mitigating nuisance costs. In municipalities where nuisance costs remain high, we recommend that alternative methods be tested for their efficacy in mitigating costs. Such methods may include public education, changing or removing financial incentives to kill bears, changing crop rotations to crops that are not attractive to bears in risk areas, promoting natural food production, using electric fences, and applying aversive conditioning techniques.

Home Ranges and Habitat Use of Sloth Bears Melursus Ursinus Inornatus in Wasgomuwa National Park, Sri Lanka

Abstract We studied home ranges and habitat selection of 10 adult sloth bears Melursus ursinus inornatus at Wasgomuwa National Park, Sri Lanka during 2002-2003. Very little is known about the ecology and behaviour of M. u. inornatus, which is a subspecies found in Sri Lanka. Our study was undertaken to assess space and habitat requirements typical of a viable population of M. u. inornatus to facilitate future conservation efforts. We captured and radio-collared 10 adult sloth bears and used the telemetry data to assess home-range size and habitat use. Mean 95% fixed kernel home ranges were 2.2 km2 (SE u200a=u200a 0.61) and 3.8 km2 (SE u200a=u200a 1.01) for adult females and males, respectively. Although areas outside the national park were accessible to bears, home ranges were almost exclusively situated within the national park boundaries. Within the home ranges, high forests were used more and abandoned agricultural fields (chenas) were used less than expected based on availability. Our estimates of home-range size are among the smallest reported for any species of bear. Thus, despite its relatively small size, Wasgomuwa National Park may support a sizeable population of sloth bears. The restriction of human activity within protected areas may be necessary for long-term viability of sloth bear populations in Sri Lanka as is maintenance of forest or scrub cover in areas with existing sloth bear populations and along potential travel corridors.

Do Black Bears Respond to Military Weapons Training

Abstract The primary function of military training areas is to support military missions; however, management of natural resources that is compatible with that function has become a focal issue on many military installations. We investigated the relationship between black bear (Ursus americanus) habitat use and weapons-firing exercises at 3 spatial scales on the western portion of U.S. Marine Corps Base Camp Lejeune (Camp Lejeune), North Carolina. In 2000 and 2001, we collected 1,494 telemetry locations for 14 bears (6 males, 8 females). We used spatial contours of human auditory disturbance levels based on the noise generated from firing activities to establish high-, medium-, and low-disturbance noise zones for each firing range. We used the multinomial logit form of discrete choice analysis to examine whether bears exhibited a spatial (i.e., general avoidance of areas associated with military activity) or temporal response (i.e., avoidance of military training areas but only when firing exercises occurred). Except for small areas near the firing positions, differences in bear use among the 3 noise zone areas was mostly a function of the prevalence of selected vegetation types and not a response to military activity. Our temporal analysis further suggested that bears did not respond to weapons exercises; the distance of bears to the nearest high-disturbance noise zone was not associated with the occurrence of weapons exercises.

Using occupancy models to determine mammalian responses to landscape changes.

Determining impacts of anthropogenic landscape changes on wildlife populations is difficult. Besides the challenges of designing field studies to document conditions before and after landscape changes occur, assessment of population responses (e.g. changes in population density) often provide poor inference because of sampling limitations. Estimation of occupancy, however, only requires data on detection or non-detection of a species and might provide better inference. To demonstrate the utility of occupancy models, we used data from an American black bear (Ursus americanus Pallas) population in North Carolina, USA to test our research hypothesis that documented declines in site occupancy of black bears would be greater near a new four-lane highway. We used multi-season occupancy models to estimate site occupancy based on bear visitation to survey sites before and after completion of the new highway and as a function of distance to the highway. Site occupancy declined from 0.81 to 0.35 between the two study phases, but was not a function of distance to the highway. Therefore, the impact of the new highway on occupancy extended to the entire study area. Our case study demonstrates that occupancy models can provide powerful inference regarding the potential impacts of landscape changes on species occupancy. As urban areas and transportation infrastructure are rapidly expanding in developing regions of the world, the need to determine how these changes affect mammal populations and how they might be mitigated increases accordingly. Because field sampling for occupancy models only requires detection data, surveys can be conducted for extensive geographic areas, thus making these surveys particularly applicable to studies of large mammals.

Landscape Characteristics of Sloth Bear Range in Sri Lanka

Abstract Little is known about the biology, status, or distribution of sloth bears (Melursus ursinus) in Sri Lanka. To facilitate sloth bear conservation, information is needed about where bears occur and what landscapes support their populations. We overlaid a 5- × 5-km grid on 1:50,000-scale land-use maps covering historic sloth bear range in Sri Lanka. In 2004, we documented current (2002–04) sloth bear presence or absence in each 25-km2 cell by interviewing knowledgeable forest users. We sought as respondents hunters, wildlife and security personnel, and others with experience in their local forests as most likely to supply reliable information regarding the presence or absence of sloth bears. We also assessed respondents perceptions and attitudes toward sloth bears. Sloth bear range occupied <17% of Sri Lankas land area with approximately 40% contained within national parks and strict nature reserves where hunting is banned and human access regulated. Except for a few small, isolated areas, sloth bear range was largely contiguous. However, large portions of sloth bear range in the north and east of the island were unprotected. Prevalence of monsoon forest was the strongest positive predictor of sloth bear presence. Elevation, road density, and human population density were significant negative predictors. Perceptions that sloth bear populations had increased were common among almost half (49%) the respondents. Although 70% of respondents regarded sloth bears as a threat, 66% supported legal protection. This positive attitude toward protection may facilitate conservation efforts. The establishment of additional protected areas in the north and east of the island and strict regulation of human activity in protected areas may enhance sloth bear conservation.

Delineating priority habitat areas for the conservation of Andean bears in northern Ecuador

Abstract We sought to identify priority areas for the conservation of Andean bear (Tremarctos ornatus) habitat in the northern portion of the eastern Andean cordillera in Ecuador. The study area included páramo and montane forest habitats within the Antisana and Cayambe-Coca ecological reserves, and unprotected areas north of these reserves with elevations ranging from 1,800 to 4,300 m. We collected data on bear occurrence along 53 transects during 2000–01 in the Oyacachi River basin, an area of indigenous communities within the Cayambe-Coca Ecological Reserve. We used those data and a set of 7 environmental variables to predict suitability of Andean bear habitat using Mahalanobis distance, a multivariate measure of dissimilarity. The Mahalanobis distance values were classified into 5 classes of habitat suitability and generalized to a resolution of 1,650-m × 1,650-m grid cells. Clusters of grid cells with high suitability values were delineated from the generalized model and defined as important habitat areas (IHAs) for conservation. The IHAs were ranked using a weighted index that included factors of elevation range, influence from disturbed areas, and current conservation status. We identified 12 IHAs, which were mainly associated with páramo and cloud forest habitats; 2 of these areas have high conservation priorities because they are outside existing reserves and close to areas of human pressure. The distribution of the IHAs highlighted the role of human land use as the main source of fragmentation of Andean bear habitat in this region, emphasizing the importance of preserving habitat connectivity to allow the seasonal movements among habitat types that we documented for this species. Furthermore, the existence of areas with high habitat suitability close to areas of intense human use indicates the importance of bear–human conflict management as a critical Andean bear conservation strategy. We suggest that a promising conservation opportunity for this species is linked to its occurrence in highland habitats, which play a key role in the maintenance of long-term water supplies.

Geostatistical analysis of allele presence patterns among American black bears in eastern North Carolina

Abstract Highways are one of the leading causes of wildlife habitat fragmentation and may particularly affect wide-ranging species, such as American black bears (Ursus americanus). We initiated a research project in 2000 to determine potential effects of a 4-lane highway on black bear ecology in Washington County, North Carolina. The research design included a treatment area (highway construction) and a control area and a pre- and post-construction phase. We used data from the pre-construction phase to determine whether we could detect scale dependency or directionality among allele occurrence patterns using geostatistics. Detection of such patterns could provide a powerful tool to measure the effects of landscape fragmentation on gene flow. We sampled DNA from roots of black bear hair at 70 hair-sampling sites on each study area for 7 weeks during fall of 2000. We used microsatellite analysis based on 10 loci to determine unique multi-locus genotypes. We examined all alleles sampled at ≥25 sites on each study area and mapped their presence or absence at each hair-sample site. We calculated semivariograms, which measure the strength of statistical correlation as a function of distance, and adjusted them for anisotropy to determine the maximum direction of spatial continuity. We then calculated the mean direction of spatial continuity for all examined alleles. The mean direction of allele frequency variation was 118.3° (SE = 8.5) on the treatment area and 172.3° (SE = 6.0) on the control area. Rayleighs tests showed that these directions differed from random distributions (P = 0.028 and P < 0.001, respectively), indicating consistent directional patterns for the alleles we examined in each area. Despite the small spatial scale of our study (approximately 11,000 ha for each study area), we observed distinct and consistent patterns of allele occurrence, suggesting different directions of gene flow between the study areas. These directions seemed to coincide with the primary orientation of the best habitat areas. Furthermore, the patterns we observed suggest directions of potential source populations beyond the 2 study areas. Indeed, nearby areas classified as core black bear habitat exist in the directions indicated by our analysis. Geostatistical analysis of allele occurrence patterns may provide a useful technique to identify potential barriers to gene flow among bear populations.