Abstract: Crotalus viridis concolor (Midget Faded Rattlesnake) is a dwarfed subspecies of the prairie rattlesnake, C.v. viridis. Midget Faded Rattlesnakes range from southwestern Wyoming, eastern Utah, and western Colorado. Their range in southwestern Wyoming is restricted to an isolated area of the lower Green River valley from the cities of Green River and Rock Springs to the Wyoming/Utah state border (Baxter and Stone, 1980, see Fig. 1). Very little is known about Midget Faded Rattlesnake ecology, and although little is known of their population status, they are considered rare throughout their range (Baxter and Stone, 1980). Midget Faded Rattlesnakes exist in very small isolated groups focused around den sites which can include between 1 and ~25 individuals (Ashton and Patton, pers. comm.). (Various investigators suspect that Midget Faded Rattlesnakes actually exist as a classic metapopulation.) This is very different from C.v.v., which can involve hundreds at a single den sites. Another marked difference between the two conspecifics is in their seasonal movements. C.v.v. have been known to travel many kilometers in a season, while Midget Faded Rattlesnakes may only travel a few hundred meters (Kyle Ashton, University of Colorado, Boulder, pers. comm.). C.v.v. have been shown to reproduce biennially and usually not before their fourth year, particularly in the northern parts of their range (Klauber 1997). Limited evidence suggest the same for Midget Faded Rattlesnakes(Ashton, pers. comm.). Such natural history traits make Midget Faded Rattlesnakes a sensitive species vulnerable to various human impacts (collection, development, recreation, etc.). Causing further complications for C.v.c. in this part of their range is the Flaming Gorge Reservoir. The construction of the dam and the filling of the Flaming Gorge Reservoir almost fifty years ago, divided the population in half and forced them to higher ground. This virtually prevents gene flow between the two sides of the reservoir. So this may have presented both spatial and genetic consequences for the population.
Purpose: Wildlife and Terrestrial - Evaluate the status of plant and animal species at risk and provide scientific guidance for their conservation and management. The objectives of this study are to investigate the population structure and dynamics of C.v.c. through genetic analyses of microsatellite DNA markers in the lab, and radio telemetry in the field. We will investigate the genetic structure of the population as a whole, as well as localized characteristics of subpopulations around the Flaming Gorge Reservoir. This, coupled with movement data collected with the use of radio telemetry, will provide the information needed to properly manage for this sensitive species.
Supplemental Information: Information used to prepare this metadata was extracted from FORT entries in the USGS BASIS+ database for 83279R4.6.0 on 11/15/2005

Progress: In work
Update Frequency: As needed

Theme Keywords: None, Conservation Genetics, DNA, molecular genetics, biotechnology, endangered species, gene flow, taxonomy, paternity analysis, genetic diversity
Place Keywords: United States, Central US, Wyoming, WY

Access Constraints: Contact principal investigator after completion of project
Usage Constraints: Contact principal investigator after completion of project