Ecology and structure of black bear (Ursus americanus) populations in the Interior Highlands of Arkansas.

摘要

In the Interior Highlands of Arkansas, Missouri, and Oklahoma, overharvest, extensive logging, and reductions of habitat availability by other means contributed to the decline of black bears (Ursus americanus). Bears were extirpated from the majority of the region by the 1940’s Oklahoma by 1915 and from Missouri by 1931. From 1958-1968, the Arkansas Game and Fish Commission undertook a reintroduction to the Ouachita and the Ozark National Forests in Arkansas. The successful growth and expansion of the released population caused these efforts to be considered one of the most successful reintroductions of carnivores. In this dissertation, I sought to examine the current population size and density of bears in the Ouachita and the Ozark National Forests in Arkansas and to explore how dispersal patterns are influenced by population expansion. Density estimates are comparable to or above previous estimates done in the late 1980’s/early 1990’s. The population appears to have maintained or exceeded previous density estimates. There was evidence for female philopatry in both source and expanding populations, with relatedness declining with distance until about 30 km. In recently expanding populations, male-male dyads followed a similar pattern to female-female dyads with relatedness decreasing with distance. Female-female dyads in expanding populations also had higher levels of closely related dyads than female-female dyads in source populations. Only in recent years have large predator reintroductions been actively pursued and the goals of restoring a functional ecosystem been approached. The genetics of reintroduction and dispersal received research attention even more recently. Dispersal and gene flow into and out of populations, a process called connectivity, fundamentally shape wildlife distribution and abundance across the landscape. Connectivity determines taxonomic distinctiveness, colonization of new sites, and persistence of both local populations and metapopulations of linked populations. With measures of connectivity in hand, we can better understand the role it plays for a particular wildlife species, and predict the consequences of changes in a human-altered landscape.