Black-tailed prairie dog monitoring at Scotts Bluff National Monument: Annual status report 2007

Peitz, David; Cribbs, J

Using methodologies outlined by Plumb et al. (2001), black-tailed prairie dog populations were monitored for the 13th consecutive year on Scotts Bluff National Monument, Nebraska. The estimated density of black-tailed prairie dogs on the main colony reached its lowest level since monitoring began in 1995. The 2007 density estimate (8.1 individuals/ha) was approximately 35 % of the average estimates for the past 13 years. However, with the exception of density estimates in 1996 and 2005, our estimated density falls within the confidence limits of other annual estimates. The 2007 prairie dog population of 147 individuals on the main colony was 271 individuals less than the 2006 population estimate and 143 individuals below the thirteen-year average (1995-2007) of 290 individuals. Both the population for the colony north of the canal (174 individuals) and the one in the Saddle Rock Unit (58 individuals) were above their four-year averages (2004-2007) of 122 and 33 individuals, respectively. While the overall shape and cohesiveness of the main colony in 2007 was similar to 2006, the number of hectares occupied declined. The black-tailed prairie dog population north of the canal and the one in the Saddle Rock Unit increased in density and area occupied, as well as in population size. In 2007, the combined colonies occupy 3.42% of the monument’s 698-ha of grassland. The presence of sylvatic plague was not observed in the black-tailed prairie dog colonies at Scotts Bluff National Monument in 2007. However, badger, known prairie dog predators were observed on the main colony. Burrowing owls were not observed during black-tailed prairie dog surveys in 2007.

Black-tailed prairie dog monitoring at Scotts Bluff National Monument: Annual status report 2007

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