Cancer Screening & Ex Situ Conservation Implications for the Mexican Grey Wolf Recovery Program

Mexican Grey Wolf (NAT GEO Archives)

Clinicians at the Chicago Zoological Society’s Brookfield Zoo in conjunction with the University of Wisconsin-Madison’s School of Veterinary Medicine are conducting an epizootiological study of malignant nasal tumors in Mexican grey wolves.  The wolves, housed at the Zoo, participate in a Species Survival Plan program, which falls under the auspices of the Association of Zoos & Aquariums’ (AZA) conservation and science initiatives.

The propagation effort is part of US Fish & Wildlife Service recovery program for the subspecies.

The current AZA program is a continuation of a bi-national (US-Mexican) captive breeding program that was launched in the late 70’s with founder stock comprised of wild wolves captured in Mexico.  The wolves or “lobos” were rendered functionally extinct in the US prior to recovery efforts.

This subspecies of grey wolf is the rarest and most genetically distinct of the 37 recognized subspecies of grey wolf–the largest extant member of the family Canidae.

The Brookfield Zoo will spearhead the research investigating the prevalence of the nasal tumors through CAT scans in conjunction with routine check-ups on the Mexican wolves in its collection.

Researchers will also conduct CT scans on approximately 150 archived osteological specimens currently stored at the Museum of Southwestern Biology (University of New Mexico) and a few specimens archived at the Field Museum in Chicago.

Nasal carcinoma, which is reported in 1-2% of domestic dogs has also been reported in Mexican wolves. There is believed to be a genetic link to the disease in canids.

The data from the study will be analyzed to help develop population management plans for the subspecies held in living institutions, including breeding of the wolves and the transfer of individual animals.  The findings will also likely influence the use of CT scans in the early diagnosis of this type of cancer.

Currently, 283 wolves of this subspecies are housed at 52 institutions across the United States.

The wolves were listed as an Endangered Species shortly after the passage of the Endangered Species Act and remain a testament to the recovery of a species on the verge of extinction. The Mexican wolves have been reintroduced to Southwestern states in the US and the Mexican state of Sonora.

Human Journey

Meet the Author
With training in wildlife ecology, conservation medicine and comparative psychology, Dr. Schaul's contributions to Nat Geo Voices have covered a range of environmental and social topics. He draws particular attention to the plight of imperiled species highlighting issues at the juncture or nexus of sorta situ wildlife conservation and applied animal welfare. Sorta situ conservation practices are comprised of scientific management and stewardship of animal populations ex situ (in captivity / 'in human care') and in situ (free-ranging / 'in nature'). He also has a background in behavior management and training of companion animals and captive wildlife, as well as conservation marketing and digital publicity. Jordan has shared interviews with colleagues and public figures, as well as editorial news content. In addition, he has posted narratives describing his own work, which include the following examples: • Restoration of wood bison to the Interior of Alaska while (While Animal Curator at Alaska Wildlife Conservation Center and courtesy professor at the University of Alaska) • Rehabilitation of orphaned sloth bears exploited for tourists in South Asia (While executive consultant 'in-residence' at the Agra Bear Rescue Center managed by Wildlife SOS) • Censusing small wild cat (e.g. ocelot and margay) populations in the montane cloud forests of Costa Rica for popular publications with 'The Cat Whisperer' Mieshelle Nagelschneider • Evaluating the impact of ecotourism on marine mammal population stability and welfare off the coast of Mexico's Sea of Cortez (With Boston University's marine science program) Jordan was a director on boards of non-profit wildlife conservation organizations serving nations in Africa, North and South America and Southeast Asia. He is also a consultant to a human-wildlife conflict mitigation organization in the Pacific Northwest. Following animal curatorships in Alaska and California, he served as a charter board member of a zoo advocacy and outreach organization and later as its executive director. Jordan was a member of the Communication and Education Commission of the International Union for the Conservation of Nature (CEC-IUCN) and the Bear Specialist Group of the IUCN Species Survival Commission (BSG-SSC-IUCN). He has served on the advisory council of the National Wildlife Humane Society and in service to the Bear Taxon Advisory Group of the Association of Zoos and Aquariums (AZA Bear TAG). In addition he was an ex officio member of council of the International Association for Bear Research and Management. Contact Email: