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

Abstract

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.

Estimating effective landscape distances and movement corridors: comparison of habitat and genetic data

“…that affect the species' movement in an optimal way to realistically estimate the cost of movement through any location in the landscape. Resistance values have usually been determined by assigning resistance scored on an arbitrary scale (Beier et al 2008, Pereira et al 2011) on the basis of expert opinion itself or in combination with literature review (Larkin et al 2004, Kautz et al 2006. However, such approaches have frequently been shown to perform poorly (Beier et al 2008, Shirk et al 2010.…”

Space and habitat use of moose in southwestern Sweden

“…Additionally, urban development was reported as the greatest threat to Florida key deer (Odocoileus virginianus clavium) population viability (Lopez et al 2003), but the threshold level of urbanization had not yet been reached (Harveson et al 2007). Nonetheless, effects of risks associated with urbanizing landscapes may threaten the viability of large mammal populations unless appropriate land use planning is employed (Meegan and Maehr 2002;Larkin et al 2004). An important requirement for creating regional land use plans that consider wildlife conservation is the identification of threshold levels of human development that, if surpassed, have potentially unsustainable consequences for wildlife populations (Harveson et al 2007).…”

Extirpation Risk of an Isolated Black Bear Population Under Different Management Scenarios

“…For this reason we see a lack of comprehensive studies of genetic differentiation focusing on taxa that are both continuously and widely distributed, although such research would provide a base of comparison for studies that identify genetic discontinuities in isolated and fragmented populations. The American black bear is no exception, because studies of this species focus mostly on isolated populations that have arisen from habitat loss and human-caused mortality in the southern part of its range (Vaughan and Pelton 1995), such as Florida (Dixon et al 2006), Louisiana (Csiki et al 2003;Larkin et al 2004), Arkansas (Csiki et al 2003;Van Den Bussche et al 2009), or Mexico (Onorato et al 2004), whereas few data exist on the core population that remains in the northern part of the distribution. Although they are capable of extensive dispersal movements of more than 200 km from their natal site (Lee and Vaughan 2003;Rogers 1987), American black bears show relatively high levels of genetic structuring across their range (Csiki et al 2003;Onorato et al 2004;Paetkau and Strobeck 1994).…”