Mexican Wolf Conservation: Two Decades of Reintroduction and the Future of Recovery

Symposium
ROOM: Rooms 27 – Picuris, 29 – Sandia and 31 – Santa Ana Combined
SESSION NUMBER: 106
 
The Mexican gray wolf is making a comeback in the Southwest following nearly two decades of reintroduction and management efforts. The reintroduction program has not been without its obstacles, not least of which is the polarization and controversy elicited by wolves wherever they exist. Despite such challenges, federal, state, tribal, organizational, and binational partnerships have been forged and cultivated to bring Mexican wolves back to the wild. The effort to reintroduce Mexican wolves is binational; the United States and Mexico are working in concert to coordinate recovery efforts for this subspecies across both wild and captive populations. This session will include presentations addressing wolf reintroduction efforts and habitat suitability in Mexico. In the United States, Mexican wolves are managed by an “Interagency Field Team”—a team comprised of federal, state, and tribal biologists. Each team member represents the directives of their own agency while coordinating across political and cultural boundaries. This session will include several presentations from cooperating agencies on the Interagency Field Team. Equally important is the field team’s involvement with livestock producers and local communities affected by wolf recovery. Field team members work diligently to address the concerns of constituents learning to coexist with wolves. In this session, we will cover topics such as coexistence in a working landscape and conflict mitigation techniques. Whether in favor of or against wolf recovery, building a culture of trust and cooperation among the public and the agencies responsible for managing wolves requires all involved to bridge this “crossroads of cultures.”

1:10PM Mexican Wolf Recovery
  Sherry Barrett; Tracy Melbihess; Maggie Dwire; John Oakleaf
Mexican Wolf Recovery In the 1970s, the United States and Mexico halted the extinction of the Mexican wolf by establishing a binational captive breeding program with seven founding wolves; there are now approximately 240 Mexican wolves in the captive breeding program in 52 facilities. We completed the Mexican Wolf Recovery Plan in 1982, and we will finalize a revised recovery plan in November 2017. We began releasing Mexican wolves from captivity into the wild in 1998 and now have at least 113 in Arizona and New Mexico. In 2011, Mexico began releasing Mexican wolves back into the wild, and as of April 2017, approximately 28 wolves inhabit the Sierra Madre Occidental Mountains in the state of Chihuahua. Recovery is affected by: 1) adequate habitat availability and suitability; 2) excessive human-caused mortality; 3) demographic stochasticity associated with small population size; and 4) continuing or accelerated loss of gene diversity in the captive or wild populations. Successful Mexican wolf recovery will require that Mexican wolf populations occupy large areas of ecologically suitable habitat with adequate prey, and land tenure and management support the occupancy and management of Mexican wolves across the landscape. We used population viability analysis to explore the conditions for viability, or resiliency, of wild Mexican wolf populations in the United States and Mexico. We consider a resilient population to be one that is able to maintain approximately a 90% or greater likelihood of persistence over 100 years. To achieve redundancy, at least two populations will need to demonstrate sufficient resiliency to provide security against extinction for one another. Representation will be addressed by the distribution of Mexican wolves across large portions of their historical range in the United States and Mexico and by ensuring wild populations retain approximately 90% of the gene diversity retained by the captive population.
1:30PM Survival and Dispersal Rates of Mexican Wolves
  John K. Oakleaf; James W. Cain III; Colby M. Gardner; Sherry Barrett; Cyrenea B. Piper
Human-caused mortality drove the Mexican wolf to the brink of extinction in the late 1970’s and early 1980’s. However, following a successful captive breeding effort, reintroduction of Mexican wolves into Arizona and New Mexico was initiated in1998 which has successfully re-established a population of approximately 113 wolves. We assessed mortality and dispersal characteristics to help elucidate the population performance of wolves since the initiation of the recovery program. We explored cause-specific mortality (e.g., human-caused versus natural mortality) and removal rates (e.g., boundary violations, nuisance, cattle depredations, and other) from 1998 to 2015 relative to population performance during that time. We generated causal mortality and removal rates, after the assumption of equal proportional hazards has been established for a given time period. We calculated an overall failure rate of wolves in the wild by combining mortality, missing, and removal rates to represent the overall yearly rate of wolves that were affected (i.e., managed, dead, or missing) in a given year. In addition, we developed Cox’s proportional hazards model to identify important covariates that influenced wolf survival. Dispersal (i.e., permanent movement of an individual from its natal territory) rates will be modeled similarly to survival data. Preliminary results demonstrate time periods and management paradigms that allowed for population growth and other time periods where removal of Mexican wolves caused population stagnation. Current management schemes have promoted a growing population and combined with dispersal characteristics should allow for ample growth of the population in New Mexico and Arizona.
1:50PM The Critical Role of the Mexican Wolf Species Survival Plan Facilities: A Binational Collaborative Effort
  Pamela Maciel
When the Mexican wolf was declared extinct there were no individuals left in the U.S. wild and only a handful remaining in the mountains of Northern Mexico. In 1976, Canis lupus baileyi was added to the Endangered Species Act and an ambitious recovery program was started. If there were ever to be a wild population again, that population would need to be initiated in captivity. In 1980, a Mexican Wolf Species Survival Plan (SSP) was created in order to build a healthy and genetically diverse population. With a captive-breeding program at its core, reproductive pairs are selected, matched, and allowed to breed through careful analysis. Those successfully breeding will produce healthy offspring that contribute to the expansion of the captive population, which will in turn contribute to the one in the wild. Zoos and other types of animal centers provide the space for this complex program to take place. Key for the SSP, these facilities located throughout the US and Mexico have housed and cared for hundreds of Mexican wolf individuals and family groups. Through their participation, the SSP institutions provide a genetically redundant stock for the population in the wild, while striving to find balance between the good of the individual and the good of the species.
2:10PM Livestock Depredation By Mexican Wolves and Non-Lethal Mitigation Techniques
  David L. Bergman; Alan May; Stewart W. Breck
Mexican wolves were extirpated from the Southwest by the middle of the last century. Mexican wolf extirpation was deemed necessary by the public and by agricultural and wildlife agencies due to perceived and real conflicts with humans and human enterprises, such as the agriculture industry (livestock depredation) and sport hunting (impacts on big game). Concerns about human safety contributed to the comprehensive effort to eliminate the wolf from the landscape. Eradication was carried out primarily by government agencies, with assistance from ranchers, hunters and bounty hunters. Since 1998, more than a 100 captive-born wolves have been released to the wild in Arizona, New Mexico, and Mexico. The Mexican Wolf Reintroduction Project is managed by the U.S. Fish and Wildlife Service in collaboration with the Arizona Game and Fish Department, Forest Service, USDA-APHIS Wildlife Services, and the White Mountain Apache Tribe. To understand and manage the Mexican wolf on the ground, Wildlife Services participates as a member of an Interagency Field Team. Wildlife Services participates with the Interagency Field Team as the lead agency for depredation investigations and to lead research on Mexican wolf depredations and to evaluate alternatives to mitigate Mexican wolf damage. The first reported depredation occurred on May 5, 1998, shortly after the return of the Mexican wolf to the Blue Range. Since 1998, over 800 incidents of reported Mexican wolf depredations have been investigated in Arizona and New Mexico including tribal lands. To mitigate the depredations, a variety of funding mechanisms have been set up to pay for compensation, pay for presence, to provide nonlethal alternatives to management. Nonlethal alternatives have included range riders, moving livestock, and fladry. As the Mexican wolf population continues to increase on the ground, the need to address depredations and public’s desire for nonlethal alternatives will continue to grow.
2:30PM Livestock Management, Calving Season, and Conflict Avoidance with Wolves on the X Diamond Ranch
  Wink Crigler
Managing for livestock depredation by wolves is like managing for drought. Livestock producers know there is a constant risk from either one but they do not know what the severity of each crisis might be; they must always be prepared to take immediate action. Success of livestock operations and for the wolf program as it currently exists is dependent on finding and applying appropriate conflict avoidance strategies. The purpose of this presentation is to explain (a) why the present management plan was pursued, (b) what the details of the management plan are and how they are being executed, (c) what the current advantages and disadvantages of the program are, and (d) the necessity of agency collaboration and partnering for adaptive management and the underlying costs therein.
2:50PM Refreshment Break
3:20PM Genetic Management and Setting Recovery Goals for Mexican Wolves in the Wild
  Larisa E. Harding; Jim Heffelfinger; David Paetkau; Esther Rubin; Jeff Dolphin; Anis Aoude
Mexican wolf recovery planning has spanned more than 3 decades, yet federal and state planners have not reached consensus on how to structure recovery efforts with the remaining inbred founder lineages to maximize genetic diversity while balancing many other demographic and social considerations. The US Fish and Wildlife Service and state wildlife agencies are working to draft a revised recovery plan specific to the Mexican wolf that will appropriately incorporate genetic concerns in recovery criteria that can be implemented on a human-dominated landscape. Inbreeding effects, where present in the remaining lineages, are stochastic and unpredictable in a management context. Despite these effects, population growth in Mexican wolves the past 5 years rivals the rate observed in Yellowstone wolves during the last decade. While small populations risk extinction via inbreeding depression, there are often larger, more imminent threats of demographics, mortality, or habitat loss that may impact success of recovery efforts. Releasing captive-reared wolves is problematic and often creates conflict in local human communities, but fostering of captive-born wolves into wild wolf packs is a viable means of increasing genetic diversity and decreasing habituated wolf-human conflict. There are many alternative ways to estimate the number of wolves per population needed to recover the Mexican wolf. Efforts should thus be made to provide for sufficient genetic diversity, but not at the expense of more immediate factors that influence successful recovery.
3:40PM Cross-Fostering: A Novel Tool for Mexican Wolf Recovery
  Julia B. Smith
All Mexican wolves (Canis lupus baileyi), both wild and captive, are descended from seven founders and three lineages; as such, this genetically distinct wolf subspecies has been afflicted by a genetic bottleneck since the onset of recovery. Reintroduced Mexican wolves have successfully bred and produced pups in the wild since 2000, and the wild population has grown to an estimated 113 individuals. However, minimizing inbreeding and maximizing retention of genetic diversity remains a key goal for the long-term success of the population. The mean kinship of the wild population is approximately 0.2409. This means that, on average, individuals within the population are as related to one another as full siblings. All current wild breeding pairs are producing pups related to the Bluestem pack, specifically breeding female F521. Of the approximately 70 Mexican wolves in the wild for which individual genetics are known, analyses indicate only 4 (all of which are males) are not descendants of F521. Introducing wolves from captivity with desirable genetic profiles into the wild population is necessary to combat potential inbreeding depression. Cross-fostering, a term for the rearing of non-maternal young by surrogate parents, is a method for introducing wolves with genetic profiles different from existing wild packs into the wild population. Cross-fostering involves the removal of captive or wild newborn pups from one den and subsequent placement into an active wild den of pups of similar age. Cross-fostering can provide an influx of genetics novel to the existing wild wolf population without potential hindrances of introducing naïve adult wolves. We have successfully accomplished cross-fostering events since 2014 and are planning more of these actions in the future to bolster recovery of Mexican wolves in the wild.
4:00PM Mexican Wolf Reintroduction Efforts in Northern Mexico
  Carlos A. Lopez Gonzalez; Nalleli E. Lara Diaz; Cristian Aguilar Miguel; Carmen Garcia Chavez; Socorro Vera Ramirez
The Mexican wolf was brought to extinction in the wild during the 1970s in the southwestern United States and northern Mexico. Resulting in the establishment of a bi-national recovery program of the smallest gray wolf subspecies in the world. The first reintroduction event in Mexico occur in 2011. Until December 2016, 33 individuals were released, 11 survived and 22 have been killed by anthropogenic activities, including poisoning and firearms. To date a small population of 14 lives in northwestern Chihuahua. The successful establishment of some individuals has produced four litters of wild born pups after four decades of absence. In addition, a natural formed couple was formed from a wild born wolf and another from captivity. Documented home ranges for Mexican wolves are in excess of 200 km2, the habitats used by them are dominated by oak, pine and pine-oak forests. Mexican wolves are feeding on White tailed deer and several small mammal species, a total of 31 livestock depredation events have occurred since 2012.The survival of released specimens has been possible thanks to an increase in tolerance of the livestock industry. Such tolerance has been affected by an array of tools including the Mexican government’s livestock insurance (compensation for depredation events), capacity building in livestock management, predator deterrence techniques, and habitat restoration. Additionally, we implemented awareness strategies in rural schools, dissemination of information about the importance of wildlife, and the consequence of using poisons through crowdsourcing. This array of efforts is only the beginning of a successful reintroduction process in Mexico. The establishment of a viable population will depend on the increase of the Mexican wolf wild population, as well as the continuous effort of all institutions involved and dedicated to the social work that will increase the tolerance of the livestock productive sector towards the subspecies.
4:20PM Mexican Wolf Habitat Suitability Analysis in the Southwestern United States and Mexico
  Enrique Martínez-Meyer; Alejandro Gonzalez-Bernal; James Heffelfinger; Julian A. Velasco; Tyson L. Swetnam; Zaira Yaneth Gonzalez-Saucedo; Jorge Ignacio Servin; Carlos Alberto Lopez-Gonzalez; Nalleli Elvira Lara-Diaz; Cristian Aguilar-Miguel; Carmen Chave
Important efforts have been made to evaluate the habitat suitability for the reintroduction and long-term persistence of the Mexican wolf (Canis lupus baileyi) both in the US and Mexico. However, such efforts used different methodological approaches and most of them cover only some portions of the historical range of this subspecies, making it impossible to have a comprehensive understanding of where and how much habitat remains for maintaining long-term, viable populations of the Mexican wolf. In the present study we performed a habitat suitability analysis across the whole historical range of the Mexican wolf using compatible input information for both countries and under a uniform methodological scheme. We implemented an additive model integrating geographic information of critical environmental variables for the Mexican wolf, including climatic-topographic suitability, land cover use, ungulate biomass, road density, and human density. Data available for the ungulate biomass index was not robust enough to generate reliable rangewide estimates, so we present a series of maps representing different scenarios depending on the thresholds used in the anthropogenic factors (road and human density) and including or not ungulate biomass estimations. Large suitable areas were found both in the US and Mexico, particularly in the higher elevation areas of east-central Arizona and west-central New Mexico in the Mexican Wolf Experimental Populations Area Management (MWEPA) in the US, and in northern Chihuahua-Sonora and Durango in the Sierra Madre Occidental in Mexico. Our results suggest that there is still sufficient suitable habitat for the Mexican wolf in both countries, but specific sites for reintroductions in Mexico and estimations of the potential number of wolves need to consider reliable field data of prey density, cattle density, land tenure, natural protected areas, safety to the field team and social acceptance.
4:40PM Perils of Recovering the Mexican Wolf Outside of Its Historical Range
  Eric A. Odell; James R. Heffelfinger; Steven S. Rosenstock; Chad Bishop; Stewart Liley; Alejandro Gonzalez-Bernal; Julian A. Velasco; Enrique Martinez-Meyer
The Mexican wolf (Canis lupus baileyi) was included in the 1973 Endangered Species Act listing of the gray wolf (C. lupus), then listed separately as a subspecies in 2015. Early accounts of its range included the Sierra Madre Occidental of Mexico, southeastern Arizona, southwestern New Mexico, and sometimes western Texas, all well supported by ecological, biogeographic, and morphological data. There have been multiple unsuccessful attempts to revise the original 1982 recovery plan and identify areas suitable for Mexican wolf reintroduction. Yet, despite the fact that 90% of its historical range is in Mexico and suitable habitat exists there, past draft recovery plans have suggested recovery occur outside historical range. Establishing Mexican wolves outside historical range is fraught with problems that may compromise or thwart recovery. Dispersal of Mexican wolves northward, continued southward movements by northern wolves, and establishment of Mexican wolves north of their historical range before they are recovered, may lead to intra-specific hybridization between the 2 separately-listed entities. If northern wolves come to occupy Mexican wolf recovery areas, the physically-larger northern wolves may dominate smaller southwestern wolves and quickly occupy breeding positions, as will their hybrid offspring. The resulting hybrid populations will not contribute towards recovery and may threaten the integrity of the Mexican wolf subspecies. Directing Mexican wolf recovery northward outside historical range threatens the genetic integrity and recovery of the subspecies, is inconsistent with current 10(j) regulations under the ESA, is unnecessary because large tracts of suitable habitat exist in Mexico, and disregards the unique characteristics for which the Mexican wolf remains listed.

 
Organizers: Julia B. Smith, Arizona Game and Fish Department, Pinetop, Arizona
 

Symposium
Location: Albuquerque Convention Center Date: September 27, 2017 Time: 1:10 pm - 5:00 pm