DOI: 10.5061/dryad.9zw3r22j9
title: Post-translocation dynamics of black-tailed prairie dogs (Cynomys ludovicianus): A successful conservation and human-wildlife conflict mitigation tool

description: Prairie dogs have declined by 98% throughout their range in the grasslands
 of North America. Translocations have been used as a conservation tool to
 reestablish colonies of this keystone species and to mitigate
 human-wildlife conflict. Understanding the behavioral responses of prairie
 dogs to translocation is of utmost importance to enhance the persistence
 of the species and for species that depend on them, including the
 critically endangered black-footed ferret. In 2017 and 2018, we
 translocated 658 black-tailed prairie dogs on the Lower Brule Indian
 Reservation in central South Dakota, USA, a black-footed ferret recovery
 site. Here, we describe and evaluate the effectiveness of translocating
 prairie dogs into augered burrows and soft released within presumed
 coteries to reestablish colonies in previously occupied habitat. We
 released prairie dogs implanted with passive integrated transponders (PIT
 tags) and conducted recapture events approximately 1-month and 1-year
 post-release. We hypothesized that these methods would result in a
 successful translocation and that prairie dogs released as coteries would
 remain close to where they were released because of their highly social
 structure. In support of these methods leading to a successful
 translocation, 69% of marked individuals were captured 1-month
 post-release, and 39% were captured 1-year post-release. Furthermore,
 considerable recruitment was observed with 495 unmarked juveniles captured
 during the 1-year post-release trapping event, and the reestablished
 colony had more than doubled in area by 2021. Contrary to our hypothesis,
 yet to our knowledge a novel finding, there was greater initial movement
 within the colony 1-month post-release than expected based on recapture
 locations compared to published average territory size; however, 1-year
 after release most recaptured individuals were captured within the
 expected territory size when compared to capture locations 1-month
 post-release. This research demonstrates that while translocating prairie
 dogs may be socially disruptive initially, it is an important conservation
 tool.
description: Translocation, processing, and release We
 translocated prairie dogs from undesirable locations to two inactive
 prairie dog colonies (Charlie’s and Charlie’s South) that had previously
 experienced plague events within the Fort Hale Bottom prairie dog complex
 at the Lower Brule Sioux Indian Reservation in central South Dakota, USA.
 At the time of capture, prairie dogs were weighed to a tenth of a gram and
 implanted with a passive integrated transponder (PIT: AVID® Identification
 Systems, Norco, CA) tag for individual identification. Sex and age classes
 (juvenile and adult) were recorded as determined by weight and appearance
 (Hoogland 1995). Prairie dogs were released into burrows to maintain the
 coteries of the source colonies. The spatial orientation of neighboring
 coteries from the source colonies was also maintained. Groups typically
 contained 1 adult male and the remaining individuals were adult females
 and juveniles of both sexes. Recapture
 To sample the population at the release site; animals were
 recaptured at approximately 1 month and 1-year post-translocation at both
 release sites to determine retention and to determine if, and how far,
 animals moved from where they were initially released. The prairie dogs
 translocated in 2017 (Charlie’s colony) were recaptured September 26–28,
 2017, at 37–39 days (recapture 1) and August 16–18, 2018, at 361–363 days
 (recapture 2) post-initial release. The prairie dogs translocated in 2018
 (Charlie’s South colony) were recaptured August 23–25, 2018, at 40–42 days
 (recapture 1) and August 21–23, 2019, 405–407 days (recapture 2) post
 initial release. Traps with individual identification tags were set in a
 10 m x 10 m grid across the entire colony where active prairie dog
 presence was visible. All trap locations within the grid were recorded.
 Captured animals were weighed, scanned for PIT tag identification number,
 marked with permanent marker, and released into the nearest burrow. All
 individuals that did not have PIT tag identifiers were marked with
 permanent marker, and sex and age were recorded. During subsequent
 trapping days, traps that contained marked individuals were released
 immediately.  Analyses Distance
 moved post-release To understand if prairie dogs
 remained within their coterie as released or if they moved within the
 colony and established new territories, we measured the distance from
 where each prairie dog was initially released to their 1-month location
 and from their 1-month location to their 1-year location in ArcGIS
 v10.7.1. Furthermore, we compared the average distance between recapture
 locations to the diameter of small (0.05 ha), average (0.32 ha), and large
 (1.01 ha) territory sizes (Hoogland 2006b) and identified the percent of
 prairie dogs that were recaptured within the given territory size across
 each time step. We used Chi-square goodness-of-fit tests to determine if
 the proportion of prairie dogs that moved in each territory size differed
 between the Charlie’s and Charlie’s South colonies. We assumed that the
 distance between release and 1-month locations and 1-month and 1-year
 locations could provide a representation of the territory size of their
 coteries. Effect of coterie dynamics on
 retention To determine if the number of individuals in
 a coterie and the age structure and sex composition of the coterie
 influenced retention, a binary response variable, we used generalized
 linear mixed models (GLMM; Jamil et al. 2013) in Program R statistical
 base package (R Development Core Team, Version 3.6.3 2020). Individuals
 were released with the coterie they were captured with, therefore, we
 included coterie as random effect to account for potential effects of
 social structure that might differ by coterie and not be explained by our
 predictor variables. In addition to sex (male or female), age (juvenile or
 adult), and the group size of the coterie, we also included weight (g),
 burrow release type (single or double openings), and release site
 (Charlie’s or Charlie’s South) as fixed effect predictor variables to
 account for additional variation. We also created a combined variable of
 sex and age (adult male or female and juvenile male or female). We did not
 allow these combined age-sex variables to enter the same model as age or
 sex because of the inherent correlation between them. No other variables
 were correlated at &gt; 0.6. Rather than run all possible model
 combinations which can result in overly complicated models with reduced
 biological meaning, we used expert opinion to determine biologically
 relevant models based on the biology of the system. We also included a
 global and a null model with just the random effect and intercept. We
 calculated AICc because of small sample size, ΔAICc, AICc weight, and
 log-likelihood to rank models (Burnham and Anderson 2002). Models within 2
 AICc of the top model were considered indistinguishable from each other
 (Burnham and Anderson 2002). Once top models were identified, we
 calculated model average parameter estimates with 95% confidence intervals
 (Arnold 2010). Parameters whose confidence intervals did not overlap zero
 were determined to be important predictors or prairie dog recapture
 success. We repeated this process for 1-month and 1-year
 post-release.