DOI: 10.5066/p9cww8gz
title: Data on black-tailed prairie dog body mass, distance to nearest male and female black-footed ferret, distance to nearest American badger, and reencounter from early to late summer 2005 (Montana) and 2009 (South Dakota)

description: Our study was conducted in 2005 on 3 colonies of black-tailed prairie dogs on lands in Phillips County, Montana administered by the Bureau of Land Management and in 2009 on a colony of black-tailed prairie dogs on Buffalo Gap National Grassland, Pennington County, South Dakota managed by U.S. Forest Service. We live-trapped black-tailed prairie dogs in daylight with wire mesh traps and marked their ears with numbered tags for individual identification. We weighed each individual to the nearest gram and collected Universal Transverse Mercator coordinates of their trapping locations over time. In Montana, trapping began on 15 June 2005 and ended on 1 October 2005. In South Dakota, trapping was conducted during 7 June through 7 October 2009. In both states, trapping was split into two sessions, early summer (June-July) and late summer (August-early October). An individual prairie dog was classified as encountered for the early summer session if it was detected at any time during that session and reencountered if it was detected one or more times during the late summer session. For each site, we calculated the center of activity for individual prairie dog capture locations as the mean of X-coordinates and the mean of Y-coordinates.

We located adult black-footed ferrets and adult American badgers via spotlighting on nearly consecutive nights each field season. Ferrets of known age and sex were individually identifiable via passive integrated transponders. In South Dakota, but not Montana, locations of adult American badgers were recorded; adult badgers of unknown sex were not individually identifiable.

We transformed prairie dog body mass (from initial capture in each state) into a binomial, categorizing prairie dogs of ≥ 600 grams at first capture as large and those of < 600 grams as small. We calculated the Euclidean distance separating each prairie dog center of activity from the closest location for any adult female ferret, any adult male ferret, and any badger. Given more intense monitoring in South Dakota for prairie dogs and ferrets alike, we were able to define individual prairie dogs as spatially "near" ferrets or badgers if their center of activity was ≤ 20 meters from the nearest adult female, male ferret, or badger spotlight locations. Data collection in Montana was less intense and the prairie dogs and ferrets were more spatially dispersed; thus, we extended the definition of “near” to ≤ 50 meters for Montana. Prairie dogs with activity centers beyond these distance cutoffs were classified as "far" from the nearest adult female, male ferret, or badger.

The first dataset (Prey Selection Data.csv) includes variables for state, prairie dog reencounter from early to late summer, prairie dog body size, distance to adult female ferret, distance to adult male ferret, and distance to badger.

The second dataset (Juvenile Prairie Dog Mass South Dakota Data.csv) includes data on juvenile prairie dog body mass in South Dakota, and includes variables for date of capture, state, prairie dog age, and the juvenile prairie dog's body mass in grams at capture. Only the mass measurements for juveniles in South Dakota were analyzed in the Larger Work manuscript cited herein.

Funding for this study was provided by the U.S. Geological Survey Fort Collins Science Center internally and through the collaborative USGS/U.S. Fish and Wildlife Service Species Survival Program.