INTRODUCTION 



Populations of several amphibian species are currently declining in the western U.S. and elsewhere 

 around the world. Acid rain, ozone depletion, pollution by toxic chemicals and heavy metals, 

 predation and/or competition by exotic species, habitat alteration, climatic changes, disease, 

 immune system problems, and combinations of several of these factors have all been suggested as 

 possible causes (Com and Fogelman 1984, Phillips 1990, Yoflfe 1992) Recognition of these 

 alarming population trends has renewed interest in the status amphibian populations in particular, 

 and raised awareness regarding current ignorance of the status of many reptile species as well. 



The amphibians and reptiles occupying the plains of eastern Montana have received scant 

 attention by naturalists and biologists. As a consequence, we know very little about the status, 

 population trends, habitat requirements, and reproductive biology of many species within this 

 region of the state. With new information acquired in the last 5 years from a series of regional 

 inventories of the herpetofauna in eastern Montana (e.g., Reichel 1995b, Hendricks and Reichel 

 1996, Hendricks and Reichel 1998, Roedel and Hendricks 1998), we are gaining an understanding 

 of abundance and population trends for several species, and are "fleshing out" known distributions 

 that were largely based on opportunistic encounters and other data at least half a century old. 



In 1805-1806 Lewis and Clark were the first to document the presence of Spiny Softshell 

 (Triofiyx spiniferus), Eastern Short-horned Lizard {Phiynosoma hernandezi). Western Hognose 

 Snake {Heterodon tiasicus). Western Terrestrial Garter Snake {Thanniophis elegans), and 

 Western Rattlesnake {Crotalis vindts) along the Missouri River in present-day eastern Montana 

 (Burroughs 1995). Most additional published accounts of amphibians and reptiles in eastern 

 Montana are concentrated along the Missouri River corridor and its tributaries. Notable among 

 these reports is that of Cope (1879), who commented on the occurrence of 5 amphibian and 3 

 reptile species between the Judith River and Armells Creek. More recently, Mosimann and Rabb 

 (1952) documented the presence of 4 amphibian and 7 reptile species in the Tiber Reservoir area 

 along the Marias River of northcentral Montana. The written record of exploration of Montana in 

 the 19"' century and first half of the 20^ century, and unpublished museum collection records, 

 provide the base for analyses of historical distributions and population trends. Additional 

 distribution and status information for border regions can be gleaned from Wheeler and Wheeler 

 (1966) for North Dakota, Visher (1914) for South Dakota, Baxter and Stone (1985) for 

 Wyoming, and Secoy and Vincent (1976) for Saskatchewan. 



Preliminary data gathered from site surveys and revisits to historical sites indicate that the 

 Northern Leopard Frog {Rana pipiens) has disappeared over much of its former range in western 

 Montana (Werner et al. 1998) and is declining in at least some areas of eastern Montana. Status 

 and population trend of several toad species {Bufo spp.) are unknown, although declines of the 

 Western Toad (Bufo hureas) have recently been reported in northern Idaho (C. Peterson pers. 

 comm), northwestern Montana (Werner and Reichel 1994, Werner et al. 1998), Yellowstone 

 National Park (Koch and Peterson 1995) and Colorado (Carey 1993). 



Land-use practices, such as large-scale logging, continue to be detrimental to resident amphibians 



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