Data on the degree and duration of deltamethrin flea control on prairie dog colonies, with 3 prairie dog species at 6 sites across 3 US states. Fleas were combed (COMB) from live-trapped prairie dogs or swabbed (SWAB) from prairie dog burrows on non-treated (Non) sites and nearby sites treated with deltamethrin dust for flea control (Dusted). Each line of data is from an individual prairie dog or burrow. The first set of data, Shortterm BACI, includes data from before-after-control-impact (BACI) experiments comparing the abundance of fleas on prairie dogs at paired non-treated and treated sites in 2 time intervals: before treatments (Before) and 2 to 65 days after treatments (After). The second set of data, Moderate 1 year, includes data on the abundance of fleas on prairie dogs at paired non-treated and treated sites 7 to 13 months after treated sites had been treated with deltamethrin dust. The third set of data, Longterm 2 year, includes data on the abundance of fleas on prairie dogs (COMB) and in burrows (SWAB) at paired non-treated and treated sites 21 to 24 months after treated sites had been treated with deltamethrin. The fourth set of data, Dust days and grams, includes data on the abundance of fleas on prairie dogs at treated sites 7 to 13 months after deltamethrin treatments, and is restricted to sites with known amounts of dust (average grams) infused into prairie dog burrows. Funding and logistical support were provided by U. S. Fish and Wildlife Service; U. S. Geological Survey; U. S. Forest Service; Bureau of Land Management; Denver Zoological Foundation; Utah Division of Wildlife Resources and the Utah Department of Natural Resources Endangered Species Mitigation Fund; Bryce Canyon National Park; Badlands National Park; Dixie National Forest; Bureau of Land Management offices in Utah (Vernal, Cedar City, Richfield, and Torrey), Colorado (Meeker), and Montana (Malta); Colorado State University; Prairie Wildlife Research; National Fish and Wildlife Foundation; World Wildlife Fund; and Centers for Disease Control and Prevention.

Data on the efficacy of deltamethrin flea control with small rodents on prairie dog colonies in Montana and Utah, 2001-2004. Data were collected on 12 colonies of 3 prairie dog (PD) species at 5 sites in Montana and Utah. PD species included black-tailed PDs (Cynomys ludovicianus, BTPDs), Utah PDs (C. parvidens, UPDs), and white-tailed PDs (C. leucurus, WTPDs). Sample sizes from 6 small rodents (Species in the data file) were sufficient for analysis: deer mice, grasshopper mice, Ord’s kangaroo rats, hispid pocket mice, dark kangaroo mice, and sagebrush voles. Efficacy of deltamethrin was assessed by combing fleas from live-trapped, anesthetized rodents on paired dusted and non-dusted plots (binary variable for DeltamethrinDust in the data file) in split colonies or separate adjacent colonies. Sampling of fleas occurred simultaneously on paired plots, thereby controlling for flea phenology when comparing flea parasitism on dusted and non-dusted plots. Each rodent was anesthetized with isoflurane and combed for 30 seconds (s) to remove fleas. During sampling of small rodents, >1 flea was found in only 5% of cases. No fleas were found in 88% of cases. Thus, we concentrated on indices of flea prevalence (FleaPrev in the data file) defined as detection or non-detection of at least 1 flea (binary 0/1).

We collected fleas from a colony of black-tailed prairie dogs on Buffalo Gap National Grassland, South Dakota, 2021. We collected flea data by combing prairie dogs and swabbing their burrows for fleas. Regarding combing, we anesthetized trapped prairie dogs (and their fleas) with isoflurane in induction chambers for processing. We combed each individual with a fine-tooth comb for 30 seconds to remove and count fleas. We released all animals, after they were recovered from anesthesia, at the location where they were captured. Regarding burrow swabbing, we used a plumber’s cable to insert a 20- by 20-centimeter flannel-cloth as deep as possible into burrow tunnels. We then shook the cable for 30 seconds to imitate movement by a host. We removed the cloth from the burrow and counted detected fleas. Total flea counts from individual prairie dogs or burrows were considered an index of flea abundance. Data were collected on four plots treated with lufenuron and nitenpyram "LN-Bit" bait pellets for systemic flea control with prairie dogs. Each LN-Bit contained 75 milligrams lufenuron and 6 milligrams nitenpyram. The LN-Bits were applied at 50 baits/acre on two plots (single treatments) and 100 baits/acre on two plots (two treatments separated by four weeks). The initial treatments were completed on 23 August 2021. The second application (on the latter two plots) was completed on 22 September 2021. Combing flea data were collected 2-21 August 2021 (before treatments) and 27 August–10 September 2021 (after initial treatments). Swabbing flea data were collected 15-17 August 2021 (before treatments) and 15-17 November 2021 (after initial treatments). The first data set (LNBit Combing Data.csv) includes data from captures and combings of individual prairie dogs and lists treatment (TREATMENT = LN50 [50 baits/acre once] or LN100 [100 baits/acre twice]), period of experiment (PERIOD = BEFORE [before treatments] or AFTER [after initial treatments]), and flea abundance (FLEAS). The second data set (LNBit Swabbing Data.csv) includes data from swabbing of individual burrrows and lists treatment (TREATMENT = LN50 [50 baits/acre once] or LN100 [100 baits/acre twice]), period of experiment (PERIOD = BEFORE [before treatments] or AFTER [after initial treatments]), and flea abundance (FLEAS).

We collected fleas from black-tailed prairie dogs (Cynomys ludovicianus) on Buffalo Gap National Grassland and Badlands National Park, South Dakota, 2020-2022. We anesthetized trapped prairie dogs (and their fleas) with isoflurane in induction chambers for processing. We combed each individual with a fine-tooth comb for 30 seconds to remove and count fleas. We released all animals, after they were recovered from anesthesia, at the location where they were captured. Total flea counts from individual prairie dogs were considered an index of flea abundance. During 2018-2020, we provided prairie dogs on 21 sites with grain bait, laced with fipronil (0.005% by weight) by placing 1/2 cup or 1/4 cup of grain at each prairie dog burrow opening on the treated sites; 18 non-treated sites functioned as experimental baselines. In 2020–2022, we live-trapped, anesthetized, and combed prairie dogs for fleas. The data release contains two spreadsheets. The first spreadsheet (FipronilNoneComparison.csv) includes data from captures and combings of individual prairie dogs on treated and non-treated sites and lists the following information for each prairie dog: DATE (date of sampling), TREATMENT (fipronil grain or none), and FLEAS (the number of fleas combed from the prairie dog). These data were used to evaluate the effect of fipronil grain on prairie dog fleas. The second spreadsheet (DaysSinceFipronil.csv) includes data from captures and combings of prairie dogs on the treated sites only, in 2020 and 2022 (when decent numbers of fleas were found on prairie dogs at the treated sites), and lists the following information for each prairie dog: YEAR (2020 or 2022), DAYSSINCE (days since fipronil grain treatment), and FLEAS (the number of fleas combed from the prairie dog). These data were used to evaluate rebounding flea numbers on the treated sites over time (under the question, how long does it take for flea numbers to rebound on sites treated with fipronil grain?). Day of sampling was not included in this analysis, because that variable would have been confounded with DAYSSINCE.

We collected fleas from colonies of black-tailed prairie dogs in Badlands National Park, South Dakota, 2020-2021. Specifically, we tested fipronil grain for flea control on two colonies: Colony A in 2020 and Colony B in 2021. To assess on-host flea numbers (in 2020 and 2021), we anesthetized trapped prairie dogs (and their fleas) with isoflurane in induction chambers for processing. We combed each individual with a fine-tooth comb for 30 seconds to remove and count fleas. We released all animals, after they were recovered from anesthesia, at the location where they were captured. To assess off-host flea numbers (in 2021), we used a plumber’s cable to insert a 20- by 20-centimeter flannel-cloth as deep as possible into burrow tunnels. We then shook the cable for 30 seconds to imitate movement by a host. We removed the cloth from the burrow and counted detected fleas. Total flea counts from individual prairie dogs or burrows were considered an index of flea abundance. The first data set (Fleas 2020.csv) includes data from captures and combings of individual prairie dogs in 2020 and the second data set (Fleas 2021.csv) includes data from captures and combings of individual prairie dogs and swabbing of individual burrows in 2021. Funding and logistical support were provided by the US Geological Survey; Prairie Wildlife Research; National Park Service; US Forest Service; and US Fish and Wildlife Service.

We live-trapped black-tailed prairie dogs on Buffalo Gap National Grassland, South Dakota, 2020-2021. We anesthetized trapped animals (and their fleas) with isoflurane in induction chambers for processing. We combed each individual with a fine-tooth comb for 30 seconds to remove and count fleas. The total flea count from an individual prairie dog was considered an index of flea abundance. We released all animals, after they were recovered from anesthesia, at the location where they were captured. Data were collected on sites treated with fipronil "FipBit" bait pellets for systemic flea control with prairie dogs. Sites were treated with FipBits containing 0.68, 0.71, or 0.83 milligrams of fipronil per FipBit. The FipBits were applied along transects at a rate of 125/hectare. Data were collected 12 July–2 September 2020 (assessing flea abundance before treatments), 9-23 September 2020 (evaluating flea control over ~1 month) and June–July 2021 (evaluating flea control over 9-10 months). The data set (South Dakota FipBits Fleas 2020-2021.csv) includes data from captures of individual prairie dogs and lists treatment (TREATMENT = 0.68, 0.71, or 0.83 milligrams of fipronil per FipBit), flea abundance (FLEAS), and period of experiment (PERIOD = BEFORE [before treatments], AFTER1 [~1 month post-treatment], and AFTER910 [~9-10 months post-treatment). Funding and logistical support were provided by the US Geological Survey; Prairie Wildlife Research; National Park Service; US Forest Service; and US Fish and Wildlife Service.

Data on prairie dog densities, flea abundance on prairie dogs, and plague epizootics in Montana and Utah, USA, 2003-2005. Prairie dog species (PDspecies in the data file) included black-tailed prairie dogs (PDs) (BTPD, Cynomys ludovicianus) in north-central Montana, white-tailed PDs (WTPD, Cynomys leucurus) in eastern Utah, and Utah PDs (UPD, Cynomys parvidens) in southwestern Utah. Field research was completed by the U.S. Geological Survey, Fort Collins Science Center, and colleagues. We used summertime visual counts as an index to PD densities (Pddensity in the data file). For each plot, we counted PDs using binoculars and/or spotting scopes from a single location outside the plot that gave the best view of the entire plot and repeated these counts on three (usually consecutive) days. We began counts just after sunrise and continued to conduct repeated systematic scans of the plot until the counts declined to about half the peak number (usually by late morning as PDs went below ground for their typical mid-day break). We converted the counts to density estimates (counts per hectare [ha]).The estimate we used to calculate density was the highest count obtained from a plot for the 3 days within a given year. We analyzed data from colonies experiencing a plague epizootic during this particular study (with an epizootic defined as greater than or equal to 90% decline in PD density). We indexed annual population change (PDpopchgProportion in the data file) by subtracting the count density estimate of the year before a plague epizootic (t1) from the density estimate during an epizootic (t2) for each plot, and dividing that by the density estimate from t1 to summarize population change as a proportionate change. We evaluated the correlation between PD population change and PD density in year t1, because negative plague-effects and the intensity of population decline may be greatest when PD densities are high in year t1 (a potential "density dependent" phenomenon discussed in a wide range of literature on disease ecology). We also evaluated the correlation between PD population change and flea abundance in year t1, because rates of plague transmission and, therefore, PD mortality are expected to increase with increasing flea densities. To assess flea abundance (PDfleas in the data file), we combed live-trapped PDs and counted the number of fleas on each PD. The PDs were live-trapped, individually marked with ear tags, and combed as thoroughly as possible for 30 seconds (s) to collect fleas. Prairie dogs were allowed to recover from anesthesia and released at their trapping locations. For each plot and year, we used the average value of flea counts (defined as flea abundance).

Data on flea parasitism and annual re-encounters of Utah prairie dogs at 5 colonies on the Awapa Plateau, Utah, USA, June-August 2013-2016. Utah prairie dogs were live-trapped and sampled on 5 colonies along an elevation gradient from 2,645 m to 2,873 m. Upon first capture each year, we anesthetized each prairie dog and fleas on its body and combed the prairie dog as thoroughly as possible for 30 s to collect fleas. We recorded the age (juvenile/adult), sex, and mass (nearest 5 g) of each prairie dog and marked its ears and body with metal tags and passive integrated transponders, respectively, for permanent identification. We indexed each prairie dog's body condition as the ratio between its weight and hind-foot length (nearest 0.10 cm) (weight:foot). Prairie dogs were allowed to recover from anesthesia and released at their trapping locations. Precipitation data for individual prairie dog colonies each year (February through September) are from the Parameter-Elevation Relationships on Independent Slopes Model (Daly et al. 2008; http://www.prism.oregonstate.edu/). The first set of data, Awapa UPD Fleas, includes data on the abundance of fleas on individual Utah prairie dogs. Each line of data is from an individual animal. Data include Utah prairie dog Age and Sex, prairie dog Condition, abundance of Fleas on the prairie dog, precipitation of the prior year (PriorPRISM), and precipitation of the current year (CurrentPRISM). The second set of data, Awapa UPD Reencounter, includes data on annual reencounters of individual Utah prairie dogs. Each line of data is for an individual prairie dog in a given annual interval; an animal must have been captured at the start of an interval to be included in that interval (e.g., a prairie dog captured in 2013 but not captured in 2014 was included in the interval 2013–2014 but was not included in the interval 2014–2015). The response variable (Reencounter) was binomial (e.g., a prairie dog captured in 2013 and 2014 but not in 2015 received a response of 1 for the interval 2013–2014 and a value of 0 for the interval 2014–2015). Predictor variables included: PriorPRISM, CurrentPRISM, prairie dog Age and Sex, prairie dog Condition, and flea parasitism of the prior year (expressed as detection/non-detection of at least 1 flea on a prairie dog in the prior year = FleaPrev). Data also include a information on trapping effort (i.e., number of trap days on a given colony) in the current year. Funding and logistical support were provided by the U. S. Geological Survey (USGS), Western Association of Fish and Wildlife Agencies, and Colorado State University. This research was also supported by Grant/Cooperative Agreement Number G14AC00403 from the USGS and Grant number RC-2634, Department of Defense Strategic Environmental Research and Development Program. Fieldwork was completed by the USGS Fort Collins Science Center, and lab work and flea identifications were completed by the USGS National Wildlife Health Center.

Mean flea counts from prairie dogs and their burrows in Utah (2000), New Mexico (2010-2012), and Montana (2016, 2019). Prairie dogs were live-trapped, anesthetized with isoflurane, and combed thoroughly for 30 or 45 seconds to remove and count fleas. Prairie dogs were allowed to recover from anesthesia and released at their trapping locations. Randomly selected prairie dog burrows were swabbed for fleas using a plumber’s snake to insert a white flannel-cloth as deep as possible into each tunnel; the cable was shook ~30 seconds, and the cloth was removed from the burrow and quickly sealed in a re-sealable zipper storage bag. Fleas were later removed from swabs and counted. Mean flea counts were calculated for each sampling site, and sampling interval, as the total number of fleas collected (from prairie dogs or burrows) divided by the total number of sampling occasions (combings or swabbings). Funding and logistical support were provided by the U.S. Geological Survey; Turner Endangered Species Fund; Turner Enterprises Incorporated; Colorado State University; Centers for Disease Control and Prevention; U.S. Fish and Wildlife Service; Charles M. Russell National Wildlife Refuge; Shortgrass Steppe Long-Term Ecological Research Project; National Science Foundation; and the U.S. Department of Defense Strategic Environment Research and Development Program.

We studied black-tailed prairie dogs and their fleas in the short-grass prairie of Vermejo Park Ranch, New Mexico, USA, June-August 2011. We live-trapped and sampled prairie dogs on 20 plots at 13 prairie dog colonies. Upon capture, we anesthetized each prairie dog (and its fleas) with isoflurane and combed the prairie dog as thoroughly as possible for ectoparasites (as described below). We marked each prairie dog's ears with tags for permanent identification and released it at the point of capture upon recovery from anesthesia. During each capture event (defined as a primary occasion), prairie dogs were anesthetized in an induction chamber, held vertically by the nape, and combed thoroughly, 3 consecutive times, 15 seconds each, over 3 separate water-lined tubs to remove and trap fleas. Individual prairie dogs were trapped 1 to 6 times over the course of the field season. In this dataset, each primary sampling occasion for an individual prairie dog (separated by 5 or more days) was considered independent of other occasions. The data set (Flea Combing Removal Data.xlsx) includes the following information for each primary sampling occasion: primary sampling occasion number (PrimaryOccasion); identification number of the unique, individual flea detected (Flea); an encounter history for each individual flea (EncounterHistory); and the Julian day of sampling in 2011 (JulianDay in the year 2011, where the first two digits are the last two digits of the year 2011 and the number after the dash is the Julian Day). Multiple individual fleas could be collected from the same prairie dog within a sampling occasion. Flea encounter histories were ‘100’ if the flea was combed into the 1st water-lined tub, ‘010’ if combed into the 2nd tub, and ‘001’ if combed into the 3rd tub.