Jeffery L. Larkin

Landscape linkages and conservation planning for the black bear in west-central Florida

The Greater Chassahowitzka black bear population is the smallest documented in North America with fewer than 20 individuals. Its future depends on landscape linkages with other bear populations that are separated by denatured habitat. We used a Geographic Information System (GIS) to identify potential landscape linkages between this isolated population and six others in Florida. Pathway lengths ranged from 60–194 km with varying potentials for facilitating black bear dispersal. Each pathway incorporated 35–88% conservation land and encountered at least 11 dispersal bottlenecks. Even pathways that incorporated extensive conservation land encountered bottlenecks that make these linkages potentially unviable. All six pathways, however, passed through ≥95% core black bear habitat. Thus, the infrastructure for a conservation network is still largely intact. The Suwannee pathway provides the best opportunity to restore connectivity between the Greater Chassahowitzka Ecosystem (GCE) and a southward colonising bear population in the Big Bend region. However, intensification of development poses an immediate threat to maintaining connectivity between the GCE and other bear populations in Florida. Through immediate strategic planning and active conservation and restoration measures, many of the generated pathways can provide long-term connectivity. Least-cost path analyses can aid in the conservation of wide-ranging animals by providing managers with a science-based, empirically derived blueprint of potential landscape linkages.

Demographic Characteristics of a Reintroduced Elk Population in Kentucky

We used radiotelemetry and field observations to study survival and reproduction of 718 reintroduced elk (Gervus elaphus) in eastern Kentucky, USA, from 1997 to 2001. Capture-related injuries accounted for 49% of the transit and post-release mortality. Annual survival was high across all age and sex classes, and ranged from 0.90 (adult females) to 0.97 (yearling females). Calving rates increased from 66% in 1998 to 92% in 2000. A high nutritional plane may explain the relatively high reproduction among females bred as yearlings, consecutive-year pregnancies, and twinning. Such high survival and reproductive rates are characteristic of colonizing ungulate populations in areas devoid of predators and competitors. Future research should focus on Kentucky-born calves to more accurately determine the effects of meningeal worm (Prelaphostrongylus tenuis) and other factors on recruitment, colonization, and population establishment.

Florida Panther Habitat Use: New Approach to an Old Problem

Abstract Although the Florida panther (Puma concolor coryi) has a history of study spanning more than 2 decades, some researchers have criticized previous habitat analyses of the panther for using daytime telemetry locations to infer 24-hour habitat use, selective use of radiotagged animals, comparison of animal locations to an inappropriate set of available resources, use of land cover maps for time periods that poorly matched some animal locations, use of locations instead of the individual animal as the sampling unit, and failure to account for telemetry error. To address all but the first of these concerns, we analyzed over 57,000 radiolocations of 100 Florida panthers and 8 introduced Texas cougars (Puma concolor stanlyana) collected from 1981 to 2003 using a Euclidean distance-based analysis (EDA), a technique that measures linear distances between telemetry locations and habitat types to determine nonrandom habitat use. We matched panther locations to 1 of 3 land cover maps reflecting cover conditions spanning 23 years to determine second- and third-order habitat selection. Panthers selected a mosaic of habitats when establishing a home range, and selected forests and avoided open wetlands within their home range. We recommend that managers give forests highest consideration when conserving this endangered species and suggest the further evaluation of the habitat value of natural openings that occur in close proximity to forested panther range.

Factors affecting reproduction and population growth in a restored elk Cervus elaphus nelsoni population

In 1997, the Kentucky Department of Fish and Wildlife Resources began a restoration program intended to translocate 200 elk Cervus elaphus nelsoni per year over a nine-year period. Initially, the age structure of males in this restored elk population was heavily skewed toward the yearling age class. We examined the reproductive performance of this elk herd for two years. During 1998, the male:adult female ratio was 35:65 (corresponding to 54:100). In 1999, the male:adult female ratio was 45:62 (corresponding to 73:100). The proportion of yearling males declined from 89% in 1998 to 31% in 1999. We used radio telemetry to locate males and females during the rut and to document calf production. Calving rates during 1998 and 1999 were 53 and 92%, respectively. Post-release movements of adult cows (N = 22) to areas devoid of males averaged 21 km and ranged within 7–57 km. Temporary Allee effects may have been responsible for annual differences in calving rates. The calving season was 67 days when breeding was dominated by yearlings and 37 days when breeding was dominated by adults. A male age structure heavily skewed toward yearlings does not appear to limit population growth. Calving rates could be improved by reducing initial post-release wanderings of adult females. Distribution of potential mates may be more important to population growth rather than balanced sex ratios and age structures.

SPATIAL CHARACTERISTICS OF AN ISOLATED FLORIDA BLACK BEAR POPULATION

Abstract The Greater Chassahowitzka Ecosystem (GCE) in west central Florida supports one of the smallest black bear (Ursus americanus floridanus) populations (< 20 adults) in North America. Females were markedly older (8.9 years) than those in other bear populations and recruitment appears infrequent. Mean annual home ranges (male: X̄ = 105 km2; female: X̄ = 31 km2) tended to be smaller than those observed in other Florida populations. Habitat was used in proportion to what was available in the GCE with a tendency to select bottomland hardwood forest. Habitat beyond the inhabited core area was dominated by anthropogenic land uses, less forest, and was not used by GCE bears. Land management must focus on maintaining the quality of existing habitat and facilitating connectivity with other black bear populations.

Density and distribution of a colonizing front of the American black bear Ursus americanus

Abstract Effective management of small expanding populations is aided by the availability of reliable estimates of distribution, as well as by demographic characteristics such as population density, genetic diversity and sex ratio. The range of the black bear Ursus americanus in the southeastern United States is expanding to include areas from which it has been extirpated for more than a century. Lack of baseline demographic data in recently reoccupied areas leaves little information on which to base emerging management needs. We estimated the current extent of expansion at the colonizing front of a black bear population in the central Appalachian Mountains and identified landscape-scale habitat characteristics affecting the expansion. In 2007, we genotyped hair samples collected throughout a 8,205-km2 area at six microsatellite loci to identify individual black bears and estimate genetic diversity. We used capture-recapture and occupancy analyses to estimate density and distribution of black bears in our study area. Our results suggest that black bears were not uniformly distributed, but were localized to high elevations and protected public conservation lands. Limited availability of high elevations to the west, north and northeast of our study area may limit further expansion. Despite a limited distribution and low estimated population density (7.51 bears/100 km2), genetic diversity at genotyped loci was high (mean Ho = 0.81). Until the population grows further, the small number of individuals in the region may be sensitive to management practices that result in mortalities, especially to females. Our research exemplifies the utility of remote genetic sampling to estimate population demographics of wide-ranging mammals throughout a large study area, particularly where private land ownership hinders intensive study.

Small Mammal Response to Vegetation and Spoil Conditions on a Reclaimed Surface Mine in Eastern Kentucky

Abstract Ecologically effective mine reclamation is characterized by the return of pre-mining floral and faunal communities. Excessive soil compaction typically results in delayed succession and low species diversity on reclaimed mine lands. We compared small mammal abundance and diversity among three levels of compaction in reforestation plots on an eastern Kentucky surface mine during 2004 and 2005. Compaction levels included 1) no compaction (loose-dumped), 2) light compaction (strike-off), and 3) high compaction (standard reclamation). Peromyscus leucopus (White-footed Mouse) made up 98% (295 of 300) of all individuals captured. In 2004, loose-dumped plots had more White-footed Mice (n = 108, mean = 36, SE = 0.58) than high-compaction plots (n = 62, mean = 20.6, SE = 3.10). Strike-off plots had more White-footed Mice (n = 59; mean = 19.6, SE = 0.66) than loose-dumped (n = 46, mean = 15.3, SE = 1.45) or high-compaction (n = 20, mean = 6.6, SE = 2.19) plots in 2005. Canopy cover and large rocks that created crevices appear to have been the factors that most influenced White-footed Mouse abundance on our study sites. Low small-mammal species diversity across all treatments was likely due to the presence of low quality habitat resulting from a poorly developed ground layer and soil compared to that found in undisturbed forest. Additionally, an insufficient amount of time since reclamation for small-mammal colonization from surrounding forests and a relatively large matrix of non-forested reclaimed mineland between our plots and potential source habitats may have also limited small-mammal diversity. To promote biodiversity and provide better wildlife habitat, we suggest that mine operators consider using reclamation methods that promote surface and vegetation heterogeneity and connectivity to source habitats.

Corridors affect dispersal initiation in reintroduced peregrine falcons

We reintroduced 33 peregrine falcons (Falco peregrinus) at two release areas with contrasting habitat configurations to assess landscape influences on dispersal. One site (Daniel Boone National Forest) had non-forested corridors within a forest matrix, whereas the other site (Tom Dorman State Nature Preserve) had forested corridors within an agricultural matrix. We used aerial telemetry and ground observation to assess differences in dispersal between sites and we used multivariate statistical analyses to detect combinations of response variables depicting landscape influences. Non-forested corridors at Daniel Boone affected post-fledging movements and initiation of dispersal, whereas no discernable pattern in dispersal initiation was observed at Dorman Preserve. Results included significant (p<0.05) differences between peregrines at Daniel Boone and Dorman Preserve in x± SD post-fledging area (PFA) size (2643.5±2599.0 and 931.7±732.1 ha, respectively), maximum movement distances (12.9±13.9 and 6.1±4.6 km, respectively), orientation of movements (second-order x angle±95% confidence interval (CI)=280.8±58.6 (non-random orientation) and 358.8±98.8 (random orientation), respectively), time spent on the PFA (16.0±12.2 and 31.0±3.3 days, respectively) and selection of agricultural habitats (Euclidean distance vectors ρ=0.66 and ρ=2.50, respectively). Selection of agriculture by peregrines released on Daniel Boone reflected selection of corridors as part of pre-dispersal movement. These results, coupled with generally unorientated movement behaviour by Dorman Preserve peregrines, provided evidence for an influence of functional landscape connectivity on dispersal in peregrines.

Food Habits of Reintroduced Elk in Southeastern Kentucky

Abstract Based on microhistological examinations of feces, Cervus elaphus (elk) from a reintroduced herd on the Cumberland Plateau in southeastern Kentucky exhibited an annual diet of grasses (24%), forbs (27%), and browse (32%). Diets shifted seasonally, possibly in response to availability and palatability. Forbs dominated the summer diet (34%), whereas grasses, forbs, and woody browse accounted for approximately equal portions of the fall diet. Grasses (40%), and browse (46%) dominated the diet during winter and spring, respectively. Grasses were eaten less during spring (10%) than during any other month. Nutritional quality does not appear to be limiting in this growing population.

MENINGEAL WORM IN A REINTRODUCED ELK POPULATION IN KENTUCKY

Meningeal worm (Parelaphostrongylus tenuis) has been implicated in the failure of several elk (Cervus elaphus) restoration attempts in the eastern United States. However, limited post-release monitoring and a paucity of published literature prevents a clear understanding of this parasites role in past failures. During winters of 1997–2001, the Kentucky Department of Fish and Wildlife Resources translocated 1,044 elk from western states to eastern Kentucky (USA) in an effort to restore a free-ranging population. We monitored 521 radio-collared elk over 4 yr to determine the impact meningeal worm had on population establishment. Thirty (23%) of 129 non-capture related mortalities were attributed to meningeal worm. Twenty-two (73%) of these meningeal worm-caused mortalities were animals <3 yr old. If younger elk born in Kentucky suffer higher mortality rates than older translocated elk, the population growth observed during the initial years of restoration may be temporary. Additional research is necessary to determine the influence meningeal worm will have on elk population growth in Kentucky.