|Scientific Name:||Sistrurus catenatus|
|Species Authority:||(Rafinesque, 1818)|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||Frost, D.R., Hammerson, G.A. & Santos-Barrera, G.|
|Reviewer/s:||Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)|
Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.
|Range Description:||The species' range extends discontinuously from the Great Lakes region of the United States (east to parts of southern Ontario (Canada) and a few sites in New York) southwest through the central and southern Great Plains region to southeastern Arizona (see Herpetological Review 21: 41), Texas Gulf Coast, and northeastern Mexico (Coahuila and Nuevo Leon) (Seigel 1986, Ernst and Barbour 1989, Stebbins 2003, Campbell and Lamar 2004). Its elevational range extends from sea level up to around 2,100 m asl (6,890 feet) (Stebbins 2003).|
Native:Mexico; United States
|Range Map:||Click here to open the map viewer and explore range.|
This species is represented by numerous occurrences (subpopulations) (Campbell and Lamar 2004 mapped hundreds of collection sites), but many may be of low quality. Paucity of information on current status precludes a range-wide estimate of the number of extant occurrences. Probably most of the remaining occurrences have less than good viability.
Its abundance is difficult to determine. The adult population size is unknown but presumably exceeds 10,000, based on the large number of subpopulations and comments by Tennant (1984), Hammerson (1999), Ernst and Barbour (1989), and Seigel (1986), but supporting data are scant.
Declines in area of occupancy and abundance undoubtedly have occurred in nearly every US state, though good documentation generally is lacking. Current trend data are not available for most areas, but this species appears to be declining in area of occupancy and abundance in many parts of the range. The rate of decline may or may not be more than 10% over 10 years or three generations.
|Habitat and Ecology:||The species' habitat varies regionally (Ernst and Ernst 2003). Habitat in the eastern part of the range includes sphagnum bogs, fens, swamps, marshes, peatlands, wet meadows, and floodplains; also open sanannas, prairies, old fields, and dry woodland; the snakes often occur in wetlands in fall, winter, and spring, in drier adjacent uplands in summer. In Missouri, massasaugas shifted from prairie in spring to upland old fields and deciduous woods in summer, returned to prairie in spring (Seigel 1986). In the western part of the range, the habitat includes grassy wetland, rocky hillsides, mesquite/scrub plains, thornbrush, oak-grass, dry prairie, desert grassland, and sand dunes of coast and offshore islands (Degenhardt et al. 1996, Hammerson 1999, Werler and Dixon 2000). In Texas, this snake often occurs near moist microhabitats or sources of water (Werler and Dixon 2000). In Mexico, massasaugas have been reported from dry shrubby areas that also include wetlands or lush riparian areas (Campbell and Lamar 2004). Hibernation occurs in underground burrows (e.g., of mammals or crayfish), crevices, or similar protected sites.|
|Major Threat(s):||Decline has been due to habitat loss and fragmentation caused by agricultural development, urbanization, damming, and drainage of wetlands (Lowe et al. 1986, Harding 1997, Werler and Dixon 2000). Wetland habitats remain highly threatened. Natural vegetation succession (encroachment of dense woody vegetation) is a significant cause of habitat loss in many areas. In some areas deliberate killing by humans is a problem, as is mortality from automobiles, late season burning, summer mowing, and pasturing of pigs in massasauga habitat. "In the Southwest, loss of prairie grasslands to overgrazing has eliminated much of the snake's original habitat" (Ernst and Ernst 2003). In some western states, the decline in agriculture may result in some habitat reclamation, but it may take a long time for abandoned fields to become suitable habitat. In Colorado, habitat loss and fragmentation resulting from agricultural expansion in the future might threaten the relatively large existing populations (Hobert et al. 2004).|
|Conservation Actions:||It is believed that at least a few dozen occurrences are protected, particularly in the northern parts of the range. Southern and western populations may occur on public lands, but the status of the protection needs investigation. It is clear that the pattern of known protection is not adequate to protect the variation of the species.|
|Citation:||Frost, D.R., Hammerson, G.A. & Santos-Barrera, G. 2007. Sistrurus catenatus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 21 May 2013.|
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