Mammalian Richness, Colonization, and Extinction in Western North American National Parks (Land -Bridge Island , Elevation, Rarity, Faunal Collapse).

Mammalian species richness, colonization, and extinction are examined in twenty-four western North American national parks. In a partial correlation analysis, area (r(,p) = .67) and elevational range (r(,p) = .54) are significantly correlated with non-volant mammalian species richness after holding latitude and vegetative cover diversity constant. Vegetative cover diversity is not significantly correlated (p > .10) with non-volant mammalian species richness after holding area, elevational range, and latitude constant. The faunal dynamics of western North American national parks are analogous to the faunal dynamics of l and -bridge islands. Within fourteen western North American national parks with the best sighting records, the number of natural post-establishment extinctions of species of lagomorphs, carnivores, and artiodactyls (1) exceeds the number of natural post-establishment colonizations of species of the same orders; (2) is inversely and significantly correlated with park area (r = -.72); and (3) is positively and significantly correlated with park age (r = .64). In a multiple logistic regression analysis, estimated initial population size at time of establishment is the best predictor of the logit P(persistence)/P(extinction) of populations of lagomorphs and carnivores in twenty-four western North American national parks. The sign of the (beta)(,i) coefficient indicates that larger populations of lagomorphs and carnivores have a higher probability of persistence. For populations of carnivores, age of maturity, which is highly correlated with individual lifetime, is also an important predictor of the logit P(persistence)/P(extinction). The sign of the (beta)(,i) coefficient indicates populations of carnivores that mature later have a higher probability of persistence after holding population size constant. For populations of artiodactyls, ecological specialization is the best predictor of the logit P(persistence)/P(extinction). The sign of the (beta)(,i) coefficient indicates populations of artiodactyls that are generalists have a higher probabilty of persistence. These results suggest that without active management of mammalian populations, western North American national parks will continue to lose their mammalian fauna. Depending upon park size, western North American national parks may lose between 0 - 100% of their species of lagomorphs, carnivores, and artiodactyls in the next 100 - 200 years.PhDEcologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/161003/1/8612590.pd