Using Expert-Opinion Surveys and GIS to Model Potential Cougar Habitat and Dispersal Corridors in Midwestern North America

Article excerpt

Abstract

Confirmations of cougar (Puma concolor) presence in Midwestern North American have increased considerably during the last decade. Although increasing cougar presence in the region may be indicative of potential eastward expansion of current cougar range via dispersal, no research has been conducted on cougar potential in the Midwest. Herein, we describe our approach to modeling potential cougar habitat and dispersal corridors in the Midwest (i.e., nine states and two provinces) using expert-opinion surveys, geospatial data, and a geographic information system (GIS). We intend to identify the distribution of potentially suitable habitat in this region where empirical data regarding cougar habitat use is not available. We will also use the map of potential habitat suitability, expert knowledge, and a GIS to evaluate potential dispersal corridors for cougars. Our results will provide information to wildlife biologists for management support, protection, and public education regarding cougar presence in the Midwest.

Introduction

Confirmations of cougar (Puma concolor) presence in Midwestern North American have increased considerably during the last decade. Although increasing cougar presence in the region may be indicative of potential eastward expansion of current cougar range via dispersal, no research has been conducted on cougar potential in the Midwest. Herein, we describe our approach to modeling potential cougar habitat and dispersal corridors in the Midwest (i.e., nine states and two provinces) using expert-opinion surveys, geospatial data, and a geographic information system (GIS). We intend to identify the distribution of potentially suitable habitat in this region where empirical data regarding cougar habitat use is not available. We will also use the map of potential habitat suitability, expert knowledge, and a GIS to evaluate potential dispersal corridors for cougars. Our results will provide information to wildlife biologists to support management, protection, and public education regarding cougar presence in the Midwest.

Increasing Cougar Presence in Midwestern North America

Historically, cougars (Puma concolor) occupied most of the western hemisphere, ranging from the Atlantic to Pacific oceans and from northern British Colombia to southern Chile (Sunquist and Sunquist 2002). However, by the late 1890s these top predators were extirpated from eastern North America because of habitat loss and intentional killing due to concerns about human safety, game populations, and livestock depredation (Sunquist and Sunquist 2002). Populations of cougars within North America have since been restricted to the West, with the exception of the small Florida panther (P. c. coryi) population in southern Florida. Currently, cougars are found in only one-third of their historical range in North America (Pierce and Bleich 2003), although cougar distribution throughout the Western Hemisphere is still the largest of any terrestrial mammal (Sunquist and Sunquist 2002).

Recently cougars have surfaced as a topic of discussion among wildlife biologists and the general public due to the possibility of dispersal and natural re-colonization east of their current geographic range. Although sightings of cougars may be unreliable, confirmed cougar carcasses, scat, and tracks (i.e., cougar "confirmations"; Figure 1) in Midwestern North America (hereafter the Midwest) have increased dramatically during the past 15 years suggesting eastward movement of cougars (Nielsen et al. 2006). For example, the Cougar Network reports >120 cougar confirmations since 1990; in Nebraska alone there have been 24 cougar confirmations during this period (Cougar Network 2006). Furthermore, Iowa and Missouri combined report 15 cougar confirmations since 1990 (Cougar Network 2006).

Many cougar confirmations exist as carcasses of young males, which are the primary dispersers in cougar populations (Sweanor et al. …