Numbers and Extent of Black-Tailed Prairie Dog Towns in Kansas

Abstract

A survey was conducted in 1992 to determine the number and extent of black-tailed prairie dog (Cynomys ludovicianus) towns in Kansas. Feed grain aerial transparencies made for the Agricultural Stabilization and Conservation Service (ASCS) were examined for evidence of prairie dog towns in 60 counties across the range of prairie dogs in Kansas. Ground truthing a portion of the sites identified as prairie dog towns determined the accuracy of the technique and was the basis for estimating the numbers of prairie dog towns and areas they occupy in each of the counties. These efforts, plus data from a 1990 survey of prairie dog towns in 8 counties, determined that approximately 1017 prairie dog towns covering 18,843 ha existed in Kansas during 1990-1992. Suggestions are provided for conducting future surveys of prairie dog towns using ASCS feed grain transparencies. The black-tailed prairie dog (Cynomys ludovicianus) is the only species of prairie dog that occurs in Kansas (Hall, 1981). The original range of the black-tailed prairie dog extended from the Rocky Mountains east to the western edge of the tallgrass prairie (Koford, 1958) and from extreme southern Canada to the Mexican border (Smith, 1958). Black-tailed prairie dogs currently occupy much of their original range, but their numbers and the area covered by their towns have been greatly reduced (U.S. Fish and Wildlife Service, 1988). Recent estimates suggest a 90-95% reduction of area occupied by prairie dogs since the early 1900's (Choate, Boggess, and Henderson, 1982; Anderson et al., 1986; Flath and Clark, 1986). Prairie dog numbers and the area covered by their towns likewise have declined in Kansas. Powell (1992) reported 84% less area covered by prairie dog towns in his 1990-1991 survey of 8 counties in western Kansas than reported by Lantz (1903) in a survey of those counties in 1902. Lantz (1903) This content downloaded from 157.55.39.223 on Wed, 24 Aug 2016 05:21:40 UTC All use subject to http://about.jstor.org/terms VOLUME 97, NUMBERS 1-2 37 estimated that prairie dog towns covered 810,000 ha of Kansas in 1902, whereas Henderson and Little (1973) estimated that only 15,000 ha of prairie dog towns existed in Kansas in 1969. The specific objective of this study was to assess the current status of prairie dogs in Kansas by determining the number of prairie dog towns, their size, and their distribution. Additionally, data collection during the study allowed an evaluation of the effectiveness of examining aerial transparencies in the files of the Agricultural Stabilization and Conservation Service (ASCS) to assess the number and area of prairie dog towns in Kansas.