The Wolf Intelligencer


Mexican Gray Wolf (Canis lupus baileyi)

Mexican Gray Wolf (Canis lupus baileyi ) – (Nelson and Goldman 1929)

Common Names: El Lobo, lobo gris

Overall population: 113 (2016 winter) 131 (2018 winter)

Physical description: Mexican wolves weigh between 60-80 lbs; Males are typically heavier and taller than the females.

Original range – “Historically, the Mexican gray wolf (Ca7>/5 lupus baileyi), or lobo, lived the farthest south of all gray wolves (C lupus) on North America and in the most arid environment at elevations from 1,200 to 3,300 m ranging throughout central and southeastern Arizona, western Texas, southern New Mexico, and most of Old Mexico (Young and Goldman 1944, Brown 1983, Parsons 1996)”

Diets of free‐ranging Mexican gray wolves in Arizona and New Mexico. Reed JE, Ballard WB, Gipson PS, Kelly BT, Krausman PR, Wallace MC, Wester DB.Wildlife Society Bulletin. 2006 Nov

Current range – Apache – Sitgreaves National Forest, the Gila National Forest and the Fort Apache Indian Reservation

Habitat / Ecology / Prey:
Habitat – mountain forests, grasslands and scrublands
PreyElk (Cervis canadensis) (Cervus elaphus canadensis nelsoni), Coues White-tailed deer (Odocoileus virginianus), desert mule deer (Odocoileus hemionus eremicus), peccaries “javelinas” (Tayassu tajacu), hares (Lepus spp.) pronghom (Antilocapra americana) Rocky Mountain Bighorn Sheep (Ovis canadensis. beaver (Castor canadensis), cottontail rabbit (Syhnlagus spp ), skunk (Mephitis spp), tree squirrels (Schmts and Tamiasciurus spp ) ground squirrels (Spermophilus spp), chipmunk (Eutamias spp), rat (Neotoma spp), mice (Permiyscus spp), vole (Microtus spp), porcupines (Erethizon dorsatum)

“I identified three mammalian species in the scats of Mexican wolves in my study area, which included Rocky Mountain Elk (Cervus elaphus), mule deer (Odocoileus hemionus), and coyote”

An assessment of abundance, diet, and cultural significance of Mexican gray wolves in Arizona. Rinkevich, S.E., 2012.

Elk (Cervus elaphus) comprised 80.3% of dietof the Mexican gray wolf. Other prey included domestic cattle (16.8%), deer(Odocoileus;,1%),squirrels (,1%), other rodents (2%), and lagomorphs (,1%). In areas of year-around grazing, 21%more livestock were consumed, compared to areas grazed seasonally.”

Summer diet of the Mexican gray wolf (Canis lupus baileyi). Merkle JA, Krausman PR, Stark DW, Oakleaf JK, Ballard WB. The Southwestern Naturalist. 2009 Dec

“Our results indicate that Elk aduhs and calves were the primary food source for Mexican wolves in Arizona and New Mexico from April 1998 through October 2001 Gray wolves in different areas rely on different prey, and usually the wolf’s diet is compnsed of 1 or 2 species (Mech 1970). Elk were the most abundant and largest prey available whhin the BRWRA (AGFD, unpublished data, USFS, unpubhshed data).”

Diets of free‐ranging Mexican gray wolves in Arizona and New Mexico. Reed JE, Ballard WB, Gipson PS, Kelly BT, Krausman PR, Wallace MC, Wester DB.Wildlife Society Bulletin. 2006 Nov

Non-prey and other wildlife –
Coyote (Canis latrans), gray fox (Urocyon cmereoargenleus) red fox (Vulpes vulpes), bobcat (Felis rufus), mountain lion (Puma concolor),  black bear (Ursus americanus), white-nosed coati (Nasua narica)

Beautiful Birds of the Southwest United States and Northern Mexico!
bald eagle (Haliaeetus leucocephalus) spotted owl (Strix occidentalis) peregrine falcon (Falco peregrinus),

Relevant Flora
ponderosa pine (Pittusponderosa), aspen (Populus iremuloides), fir (Abies spp ), juniper (Juniperus spp ), piflon (Pirrus cembroides), mesquhe (Prosopis spp ), evergreen oaks {Quercus spp )

Unique behaviors:

Legal and Cultural Background:
White Mountain Apache Tribe
Mexican Wolf Management – U.S. Fish & Wildlife Service’s Mexican Wolf Recovery
CONANP – Comisión Nacional de Áreas Naturales Protogidas

International Wolf Center – Arizona, New Mexico, Mexico,
Lobos of the Southwest
Grand Canyon Wolf Recovery Project (Flagstaff, Arizona)
Center for Biological Diversity (Multi-State, Tucson, Arizona)
Endangered Wolf Center (Eureka, Missouri)
The Rewilding Institute (Albuquerque, New Mexico)
Western Environmental Law Center (Eugene, Oregon; Helena, Montana; Taos. New Mexico)
Naturalia – Non-profit group collaborating on Mexico’s wolf reintroduction efforts
Lobo MexicanoFundacion Lince: En Pro de La Biodiversidad
Centro Ecológico del Estado de Sonora (CEDES) Ecological Center of Sonora (CEDES)
recuperación del lobo mexicano el Comité Binacional para la Recuperación del Lobo Mexicano.
WWF  Lobo Mexicano

Taxonomic/Genetic Information:


Further Reading
Wolves in Arizona
Wolves in New Mexico
Wolves in Mexico
Wolves in Texas
Mexican Gray Wolf Fact Sheet, USFW
Mexican wolf recovery plan – 2017 – first revision
United States – Mexico Border / Wildlife Impact

Journal Articles/ Scientific Publications:

Ecological and social drivers of Mexican gray wolf (Canis lupus baileyi) home range patterns across spatiotemporal scales. Lichwa EM. 2021


Elucidating factors influencing home range size are fundamental relationships that can be described for any wildlife species, particularly those of conservation concern. The Mexican gray wolf (Canis lupus baileyi) is an endangered sub-species of the gray wolf whose home range patterns have not yet been studied. I estimated home range sizes for 22 Mexican wolf packs using Brownian Bridge Movement Models (95% UD). Generalized linear mixed effect models were used to evaluate environmental and social variables across four timeframes. Annual home range size was inversely related to human density and tree cover. During the denning period, home range was inversely related to litter size and increased with pack size. Post denning home range was inversely related to ungulate biomass and positively related to pack size. During the non-denning season, home range was inversely correlated with snow depth. Results found herein both confirm as well as deviate from results found in other wolf populations, notably, the inverse correlation with pack size at the annual scale, but positive correlation at seasonal timeframes. The opposite relationships with home range and pack size, and the significance of ungulate biomass at the seasonal scale but not the annual scale demonstrates the importance of evaluating factors influencing home range using a multiscale approach as home range size may be differentially influenced by the same variable across timescales. Thus, future home range studies should use a multiscale approach to discern relevant factors for species across timeframes of interest.

Rangewide habitat suitability analysis for the Mexican wolf (Canis lupus baileyi) to identify recovery areas in its historical distribution. Diversity and Distributions. 2021 Apr


To develop an updated distribution model and habitat suitability analysis for the Mexican wolf, to inform the recovery efforts in Mexico and the United States.

Mexico and the southwestern United States.

We used an ensemble species distribution modelling (SDM) approach and a spatial analysis combining anthropogenic and ecological variables, including, for the first time, rangewide relative density estimates of wild ungulates, to determine the extent of suitable habitat for wolves within a region that includes the known historical range of the Mexican wolf and adjacent areas.

The results showed that the modelled distribution of the Mexican wolf extended from central Arizona and New Mexico, and western Texas in the United States, southwards along the Sierra Madre Occidental and the Sierra Madre Oriental, to the high sierras of Oaxaca, in Mexico. The habitat suitability models indicated that large tracts (>81,000 km2) of high‐quality habitat still exist for the Mexican wolf in the southwestern United States, and the Sierra Madre Occidental and the Sierra Madre Oriental in Mexico, which could ensure recovery within its historical range.

Main conclusions
The recovery of the Mexican wolf is a complex, multidimensional socio‐ecological challenge, which requires binational cooperation guided by reliable information and robust scientific procedures. The next step is to carry out specific socio‐ecological studies and actions for selected candidate sites to assess their viability for hastening its recovery.

Effect of Canine Parvovirus and Canine Distemper Virus on the Mexican Wolf (Canis lupus baileyi) Population in the USA. Justice-Allen A, Clement MJ. Journal of wildlife diseases. 2019 Feb

Predicting spatial factors associated with cattle depredations by the Mexican wolf (Canis lupus baileyi) with recommendations for depredation risk modeling. Amirkhiz RG, Frey JK, Cain III JW, Breck SW, Bergman DL. Biological conservation. 2018 Aug

An Individual-Based Model for Predicting Dynamics of a Newly Established Mexican Wolf (Canis lupus baileyi) Population;JV Gedir, JW Cain – 2018

[HTML] Perils of recovering the Mexican wolf outside of its historical range
EA Odell, JR Heffelfinger, SS Rosenstock, CJ Bishop… – Biological Conservation,  2018 Apr

Genome-Wide Analysis of SNPs Is Consistent with No Domestic Dog Ancestry in the Endangered Mexican Wolf (Canis lupus baileyi) RR Fitak, SE Rinkevich, M Culver – Journal of Heredity 2018 Mar

Mexican wolves are a valid subspecies and an appropriate conservation target
RJ Fredrickson, PW Hedrick, RK Wayne… – Journal of …, 2015

Trophic Cascades and Conservation: Analyzing the San Juan National Forest as a Potential Extension of the Mexican Gray Wolf Recovery Program
R Utt – 2017

Clarifying historical range to aid recovery of the Mexican wolf; JR Heffelfinger, RM Nowak… – The Journal of Wildlife …, 2017

Defense of an expanded historical range for the Mexican wolf: A comment on Heffelfinger et al. Hendricks SA, Koblmüller S, Harrigan RJ, Leonard JA, Schweizer RM, Vonholdt BM, Kays R, Wayne RK. The Journal of Wildlife Management. 2017 Nov

Long-term quantification of faecal glucocorticoid metabolite concentrations reveals that Mexican grey wolves may habituate to captivity; I Escobar-Ibarra, L Mayagoitia-Novales… – The European …, 2017

Genetic management and setting recovery goals for Mexican wolves (Canis lupus baileyi) in the wild; LE Harding, J Heffelfinger, D Paetkau, E Rubin… – Biological …, 2016

Serosurvey of vector-borne diseases in the Mexican wolf (Canis lupus baileyi) in captivity; F Morales-Soto, C García-De la Peña… – Archivos de Medicina …, 2016

Variations in the locomotor activity of the Mexican wolf (Canis lupus baileyi) respect to moon periodicity: A study in an outdoor enclosure; JCS Ferrer, J Servin, R Lopez-Wilchis – 2016 –

The Effects of Crowd Size and Keeper Presence on the Stereotypic Pacing of Mexican Gray Wolves (Canis lupus baileyi);M MacDonald – 2016

Estudio serológico de enfermedades transmitidas por vectores en el lobo mexicano (Canis lupus baileyi) en cautiverio; F Morales-Soto, RI Rodríguez-Vivas… – Archivos de medicina …, 2016

A noninvasive method to detect Mexican wolves and estimate abundance. Piaggio AJ, Cariappa CA, Straughan DJ, Neubaum MA, Dwire M, Krausman PR, Ballard WB, Bergman DL, Breck SW. Wildlife Society Bulletin. 2016 Jun

Mexican wolves are a valid subspecies and an appropriate conservation target. Fredrickson RJ, Hedrick PW, Wayne RK, vonHoldt BM, Phillips MK. Journal of Heredity. 2015 Jul

Making Space for Mexican Wolves: Technology, Knowledge and Conservation Politics. Decker, P.D., 2013

Re-introduction of the Mexican wolf in the Sierra Madre Occidental, Mexico. Romo JL, Webels RA, Bernal AG, Gonzalez ZY, Aguilar C, Chavez CG, Diaz NE, Gonzalez CA. Global re-introduction perspectives. 2013

Vitrification of oocytes from endangered Mexican gray wolves (Canis lupus baileyi). Boutelle S, Lenahan K, Krisher R, Bauman KL, Asa CS, Silber S. Theriogenology. 2011 Mar

Domestic calf mortality and producer detection rates in the Mexican wolf recovery area: Implications for livestock management and carnivore compensation schemes. Breck SW, Kluever BM, Panasci M, Oakleaf J, Johnson T, Ballard W, Howery L, Bergman DL. Biological Conservation. 2011 Feb

Evaluating trapping techniques to reduce potential for injury to Mexican wolves. Turnbull TT, Cain III JW, Roemer GW. US Geological Survey; 2011

Genetic rescue guidelines with examples from Mexican wolves and Florida panthers. Hedrick PW, Fredrickson R. Conservation genetics. 2010 Apr

Captive breeding and the reintroduction of Mexican and red wolves. Hedrick PW, Fredrickson RJ. Molecular Ecology. 2008 Jan

Genetic rescue and inbreeding depression in Mexican wolves. Fredrickson RJ, Siminski P, Woolf M, Hedrick PW. Proceedings of the Royal Society B: Biological Sciences. 2007 Sep

Relationship of inbreeding with sperm quality and reproductive success in Mexican gray wolves. Asa C, Miller P, Agnew M, Rebolledo JA, Lindsey SL, Callahan M, Bauman K. Animal Conservation. 2007 Aug

The bureaucratically imperiled Mexican wolf. Povilitis A, Parsons DR, Robinson MJ, Becker CD.Conservation Biology. 2006 Aug

Mexican wolf Blue Range reintroduction project 5 year review: technical component. Team IF, Tribe WM. 2005 Dec 31.

Differentiating Mexican gray wolf and coyote scats using DNA analysis. Reed JE, Baker RJ, Ballard WB, Kelly BT. Wildlife Society Bulletin. 2004 Sep.

Canine parvovirus enteritis, canine distemper, and major histocompatibility complex genetic variation in Mexican wolves. Hedrick PW, Lee RN, Buchanan C. Journal of Wildlife Diseases. 2003 Oct

Return of the Mexican gray wolf: Back to the blue. Holaday B. University of Arizona Press; 2003.

Body size in endangered Mexican wolves: effects of inbreeding and cross-lineage matings. Fredrickson R, Hedrick P. InAnimal Conservation forum 2002 Feb

Restoring the Mexican gray wolf to the mountains of the Southwest. Brown WM, Parsons DR. Large mammal restoration: Ecological and sociological challenges in the 21st century. Island Press, Covelo, CA; 2001 Oct

Mexican wolf recovery: three year program review and assessment. Paquet PC, Vucetich J, Phillips MK, Vucetich L. Prepared by the Conservation Breeding Specialist Group for the United States Fish and Wildlife Service. 2001 Jun

Major histocompatibility complex (MHC) variation in the endangered Mexican wolf and related canids. Hedrick PW, Lee RN, Parker KM. Heredity. 2000 Dec

Duration and frequency of chorus howling of the Mexican wolf (Canis lupus baileyi). Servín J. Acta zoológica mexicana. 2000 Mar

” Green fire” returns to the Southwest: reintroduction of the Mexican wolf. Wildlife Society Bulletin. Parsons DR. 1998 Dec

Reintroducing the Mexican wolf: will the public share the costs, or will the burden be borne by a few. Nat. Resources J.. Carson JM. 1998

Endangered Species Act, Section 10 (J): Special Rules to Reestablish the Mexican Wolf to Its Historic Range in the American Southwest. Cribb S. Environs: Envtl. L. & Pol’y J.. 1998

Differences in winter activity, courtship, and social behavior of two captive family groups of Mexican wolves (Canis lupus baileyi). Bernal JF, Packard JM. Zoo Biology: Published in affiliation with the American Zoo and Aquarium Association. 1997

Genetic evaluation of the three captive Mexican wolf lineages. Hedrick PW, Miller PS, Geffen E, Wayne R. Zoo Biology: Published in affiliation with the American Zoo and Aquarium Association. 1997

Relationships and genetic purity of the endangered Mexican wolf based on analysis of microsatellite loci. García‐Moreno J, Matocq MD, Roy MS, Geffen E, Wayne RK. Conservation Biology. 1996 Apr

Hematologic values of captive Mexican wolves. Drag MD. American journal of veterinary research. 1991 Nov

An evaluation of the ecological potential of White Sands Missile Range to support a reintroduced population of Mexican wolves. Bednarz JC. US Fish and Wildlife Service; 1989

Mexican wolf recovery plan. US Fish and Wildlife Service. Team, M.W.R., 1982.


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