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Estimated Areal Extent of Colonies of Black-tailed
Prairie Dogs in the Northern Great Plains

John G. Sidle, Douglas H. Johnson, and Betty R. Euliss

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Abstract: During 1997-1998, we undertook an aerial survey, with an aerial line-intercept technique, to estimate the extent of colonies of black-tailed prairie dogs (Cynomys ludovicianus) in the northern Great Plains states of Nebraska, North Dakota, South Dakota, and Wyoming. We stratified the survey based on knowledge of colony locations, computed 2 types of estimates for each stratum, and combined ratio estimates for high-density strata with average density estimates for low-density strata. Estimates of colony areas for black-tailed prairie dogs were derived from the average percentages of lines intercepting prairie dog colonies and ratio estimators. We selected the best estimator based on the correlation between length of transect line and length of intercepted colonies. Active colonies of black-tailed prairie dogs occupied 2,377.8 km² ± 186.4 SE, whereas inactive colonies occupied 560.4 ± 89.2 km². These data represent the 1st quantitative assessment of prairie-dog colonies in the northern Great Plains. The survey dispels popular notions that millions of square kilometers of colonies of black-tailed prairie dogs exist in the northern Great Plains and can form the basis for future survey efforts.

Key words: aerial survey, black-tailed prairie dog, colony abundance, Cynomys ludovicianus, Nebraska, North Dakota, northern Great Plains, South Dakota, Wyoming

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This resource is based on the following source (Northern Prairie Publication 1163):

Sidle, John G., Douglas H. Johnson, and Betty R. Euliss.  2001.  
     Estimated areal extent of colonies of black-tailed prairie dogs in 
     the northern Great Plains.  Journal of Mammalogy 82(4):928-936.

This resource should be cited as:

Sidle, John G., Douglas H. Johnson, and Betty R. Euliss.  2001.  
     Estimated areal extent of colonies of black-tailed prairie dogs in 
     the northern Great Plains.  Journal of Mammalogy 82(4):928-936.  
     Jamestown, ND: Northern Prairie Wildlife Research Center Online.  
     http://www.npwrc.usgs.gov/resource/2002/pdogcol/index.htm
     (Version 25JUL2002).

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Table of Contents

• Introduction
• Materials and Methods
  • Line-intercept sampling
  • Aircraft operations
  • Analysis
• Results and Discussion
• Acknowledgments
• Literature Cited

Tables and Figures

• Table 1 -- Estimates of coverage for active and inactive colonies of black-tailed prairie dogs.
• Table 2 -- Pearson correlation coefficients between length of line flown and line length that intercepts colonies.

• Figure 1 -- Range of the black-tailed prairie dog and the region surveyed by aircraft to estimate areal coverage.

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John G. Sidle, United States Department of Agriculture, Forest Service, Great Plains National Grasslands, 125 North Main Street, Chadron, NE 69337
Correspondent: jsidle@fs.fed.us
Douglas H. Johnson and Betty R. Euliss, United States Geological Survey, Northern Prairie Wildlife Research Center, 8711 37th Street SE, Jamestown, ND 58401

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