DOI: 10.5061/dryad.2280gb5z8
title: Factors affecting the recovery of Mexican wolves in the Southwest United States

description: Recovering and maintaining large carnivore populations is a global
 conservation challenge that requires better knowledge of the factors
 affecting their populations, particularly in shared landscapes (i.e.,
 non-protected areas where people occupy and or utilize the
 land). The Mexican wolf (Canis lupus baileyi) is an endangered
 wolf subspecies being recovered on shared landscapes in the Southwest
 United States and Mexico. We used data from the U.S. program to model
 population growth, evaluate the impact of management removal and illegal
 killing relative to other demographic factors, and test hypotheses about
 factors influencing rates of management removal and illegal
 killing. From 1998–2019, the population growth averaged 12% per
 year. Rates of natural reproduction, illegal killing, and other mortality
 remained consistent over the 22 years, while releases, translocations, and
 management removals varied markedly between two time periods, phase 1:
 1998–2007, and phase 2: 2008–2019. The number of wolves removed
 for conflict management was higher during phase 1 (average ~13 per year,
 rate = 24.8%) than phase 2 (average of ~5 per year, rate = 5.2%). This
 decrease in management removal resulted in the wolf population resuming
 growth after a period of population stagnation. Two factors influenced
 this decrease: a change in policy regarding the removal of wolves
 (stronger modeling support) and a decrease in the number of captive-reared
 adult wolves released into the wild (weaker modeling
 support). Illegal mortality was relatively constant across both
 phases, but after the decrease in management removal, illegal mortality
 became the most important factor (relative importance shifted from 28.2%
 to 50.1%). Illegal mortality was positively correlated with rates of
 reintroduction and translocation of wolves and negatively correlated with
 the rate of management removal. Using management removal to
 reduce human-carnivore conflict can have negative population impacts if
 not used judiciously. Recovering and maintaining carnivore populations in
 shared landscapes may require greater tolerance of conflict and more
 emphasis on effective conflict prevention strategies and compensation
 programs for affected stakeholders.
description: Within the United States, Mexican
 wolves are being recovered in south-central Arizona and New Mexico;
 specifics of the area can be found in (U.S. Fish and Wildlife Service
 2017). Mexican wolves have been monitored intensively since the beginning
 of the reintroduction effort in 1998. To aid monitoring, a high percentage
 of wolves are radio-collared each year (range 38% to 100%, weighted
 average based on end-of-year population count and collars was 52%).
 Utilizing radio collars and other methods the Interagency Field Team
 (i.e., employees from Arizona Game and Fish Department, New Mexico
 Department of Game and Fish, USDA APHIS-Wildlife Services, US Forest
 Services, US Fish and Wildlife Service, and White Mountain Apache Tribe)
 then conducts annual population counts and pup counts and monitors
 continually for mortality events. Initially (1998–2004), the Interagency
 Field Team determined population estimates and pup counts via howling
 surveys (Harrington and Mech 1982, Fuller and Sampson 1988), tracks, and
 visual observations during aerial (fixed wing) and ground radio-telemetry
 efforts (White and Garrott 1990). Ground observations were collected
 opportunistically through the least intrusive methods possible, and the
 Interagency Field Team avoided any disturbance of den areas. In later
 years (2005–2019), they incorporated helicopter counts in January to
 verify and collect additional information from ground counts and
 incorporated the increased use of remote cameras, observations at den
 sites, and trapping for younger pups (2009–2019). Currently, the
 Interagency Field Team utilizes data collected from November 1 through
 mid-February to develop an end-of-the-year observed minimum population
 count.  The only processing
 of the data that we have done was to combine different sources of
 non-management and non-illegal killing into “other mortality”. We combined
 natural mortality, mortality from vehicles, and other legal mortality into
 other mortality for our analysis. 
description: # Factors affecting the recovery of Mexican wolves in the Southwest United
 States --- The data provided (MexicanWolfData.csv) are on Mexican Wolves
 (*Canis lupus baileyi*) from 1998–2019 in Arizona and New Mexico, USA,
 following the reintroduction in 1998. The data are from annual monitoring
 efforts of the population. ## Description of the data and file structure
 The data are provided in .csv format and include a table with a row for
 each year in the study (1998-2019) and 9 columns. The columns are: * Year
 = the year for which the data apply * Population = the population count
 based on end-of-year surveys * Pup recruitment = a count of the number of
 pups recruited into the population based on surveys * Captive release =
 the number of animals that were captively reared and released into the
 population * Translocation = the number of animals that had previously
 been removed during management removal events that were translocated and
 released into the population in a given year * Illegal killing = the
 number of known illegal killing events * Other mortality = the number of
 natural deaths, vehicle deaths, and other legal killing deaths not
 accounted for in other mortality sources in a given year * Unknown
 mortality = the number of wolves with known deaths from unknown causes *
 Management removal = the number of wolves that were removed by management,
 either to later be translocated (could be in the same year or in later
 years) or that were permanently removed from the population ##
 Sharing/Access information Data was derived from the following source: *
 [https://www.fws.gov/media/mexican-wolf-2019-annual-progress-report](https://www.fws.gov/media/mexican-wolf-2019-annual-progress-report) ## Code/Software These data were analyzed for the manuscript Breck et al. entitled "Factors affecting recovery of Mexican wolves in southwestern USA". The analyses were conducted in the program R (version 4.2.2) using a custom-coded Bayesian hierarchical model. The code is available through Zenodo: [https://doi.org/10.5281/zenodo.8140794](https://doi.org/10.5281/zenodo.8140794) ## Post-publication data clarification These data reflect the version available at the time of analysis and used in Breck et al, 2023. The management agency has since made minor adjustments to 14 of 264 data records, and those changes were between 1 and 3 individuals off from the data used in our paper. We evaluated the impacts of those data changes and found no material impact on model results or conclusions. For transparency, we note these data adjustments exist, but we have retained the original dataset to ensure consistency with our published analyses.