@conference {50680,
	title = {Human influences on range contractions of North American carnivores and ungulates},
	booktitle = {Carnivores 2004 Conference: Defenders of Wildlife},
	year = {2004},
	month = {November 15, 200},
	pages = {132},
	address = {Santa Fe, NM},
	abstract = {Knowledge of the geographical distribution of species is important for conservation biology. However, few studies have examined the dynamics of species ranges and changes over time and space. In addition, we know very little about human influences on species range changes at the continental scale. We compared the historic and current geographical ranges of 43 North American carnivores and ungulates to identify large-scale patterns in range contractions and expansions. Our objectives were to determine the degree of human influence on species range changes, to describe range changes with regard to biomes and elevation, and to describe changes in species richness. Seventeen of the species had experienced range contractions over more than 20\% of their historic range. Electivity indices showed a strong correlation between human influence and species range contractions. In areas of higher human influence, species were more likely to contract and less likely to persist. Species richness had also declined considerably since historic times. The temperate grasslands and temperate broadleaf{\textquoteright}mixed forest biomes lost the highest average number of species, while the boreal forest and tundra showed fewer numbers of species lost. Our spatial quantification at the continental scale showed that species contractions have been widespread, crossing regional and country boundaries and that this rapid collapse occurred over the course of only one to two centuries. The results of this study can be used to improve scientists{\textquoteright} knowledge of historical reference conditions and to provide input for wildlife reintroductions and for the creation of wildlife reserves.},
	keywords = {biomes, carnivores, elevation, human influences, North America, range contractions, species range changes, ungulates},
	author = {Andrea S. Laliberte and Ripple, W.J.}
}
