News Release
Contact: Maureen Jasculca, Jasculca-Terman, 763.442.0165,
              Sondra Katzen, director of public relations, 708.688.8351,
May 26, 2023
Chicago Zoological Society Continues to Help Increase Genetic Diversity
of Wild Mexican Wolf Population
Six Puppies Born at Brookfield Zoo being Fostered by Wild Wolf Packs
Brookfield, Ill. — On April 27, seven Mexican wolf puppies were born at Brookfield Zoo, but guests will only see one of the males when he emerges from the den in the coming weeks. That is because, on May 6, the other six puppies—four males and two females—were placed in wild Mexican wolf dens as part of the U.S. Fish and Wildlife Service's (USFWS) Mexican Wolf Recovery Program.

At 9 days old, the six puppies, accompanied by veterinary and animal care staff from the Zoo, were flown to Arizona, courtesy of LightHawk Conservation Flying, a nonprofit organization that partners pilots with organizations to help transfer endangered species to new homes among other conservation projects. From there, the Mexican Wolf Interagency Field Team placed three of the puppies in a wild pack in southeast Arizona and three into a wild pack in southwest New Mexico. Three natal pups from each of the wild den sites were relocated as well. This process of cross-fostering puppies with different packs then the ones they were born into, is done to help enhance the genetic diversity of the overall Mexican wolf population.

“We are proud to be a partner in the Mexican Wolf Recovery Program,” said Mark Wanner, director of carnivore/small mammal care and conservation for the Chicago Zoological Society. It is very rewarding knowing that Brookfield Zoo is contributing to help repopulate this iconic species that was once extirpated in the wild. To be able to share why the Mexican wolf is so important to its native ecosystem, hopefully inspires our guests to care and support conservation efforts for the species.”

The recent litter born at Brookfield Zoo is the second for the alpha wolf pair—4-year-old Vivilette and 10-year-old Amigo—who has resided at the Zoo’s Regenstein Wolf Woods since 2020 and 2021, respectively. In addition to the puppy from this year’s litter who is remaining at the Zoo, a 1-year-old male named Joe Jr. can also be seen.

The Chicago Zoological Society, which manages Brookfield Zoo, has been a partner in the multi-agency recover program since 2003. Its objective is to re-establish the Mexican wolf population in its native habitat of the southwestern United States and Mexico. Over the years, the Society has had puppies from several litters cross-fostered with wild packs, has had puppies born in the wild cross-fostered in the Zoo’s Mexican wolf pack, and even had an adult from the Zoo released to the wild and successfully raise puppies.

A few successes of the program were confirmed earlier this year during the USFWS’s annual Mexican wolf census. A male and a female wolf were identified as the offspring of a wolf, who was born at Brookfield Zoo several years ago and cross-fostered as a pup with a wild wolf pack. Additionally, in 2022, three pups born at Brookfield Zoo were placed with the Whitewater Canyon wolf pack. During the recent census, USFWS identified the pack and it appears the litter survived, which means it is possible the pups born at the Zoo may be alive and thriving.

“This year we fostered 16 Mexican wolf pups from our partner facilities to the wild,” said Brady McGee, Mexican Wolf Recovery coordinator for the U.S. Fish and Wildlife Service. “These genetically valuable pups, along with those from previous years, are vitally important to improving the genetic diversity of the wild population of Mexican wolves. This remarkable achievement is a testament to the collective efforts of everyone involved in this conservation endeavor, including Brookfield Zoo.”

According to the Interagency Field Team that conducted both ground and aerial counts this past winter, the 2022 population estimate represents a 23 percent increase from the minimum of 196 wolves in 2021. This marks the seventh consecutive year of population growth and a more than doubling in size since 2017. The population is distributed with 136 wolves in New Mexico and 105 in Arizona.

Mexican wolves are the rarest subspecies of gray wolves in North America. Approximately 4,000 wolves once lived in their historic range, which included central and northern Mexico and the southwestern United States. In May 1976, USFWS added the species to the Endangered Species List. From the 1980s until 1998, when reintroduction efforts began, Mexican wolves were considered extinct in the wild. Their demise, which began in the early 1900s, was the result of antipredator campaigns in the United States and Mexico.

Those interested in helping care for the Mexican wolf pack at Brookfield Zoo can contribute to the Animal Adoption program. For $35, a recipient receives the Basic Package, which includes a 5-inch x 7-inch color photograph of a Mexican wolf, a personalized certificate of adoption, a Mexican wolf fact sheet, an Animal Adoption program decal, and an invitation to the exclusive 2023 Animal Adoption summer event. To purchase, visit

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Photo Captions (credit: CZS-Brookfield Zoo)
001: Seven Mexican wolf puppies were born at Brookfield Zoo on April 27. On May 6, six of the puppies were flown to Arizona to be placed with wild wolf packs as part of the U.S. Fish and Wildlife Services’ Mexican Wolf Recovery Program, which helps enhance the genetic diversity of the overall Mexican wolf population.
8761 and 8807: Dr. Lily Parkinson, a clinical veterinarian at Brookfield Zoo, examines a 9-day-old Mexican wolf puppy. The puppy was one of six flown to Arizona to be placed with wild wolf packs as part of the U.S. Fish and Wildlife Services’ Mexican Wolf Recovery Program.
8835: A 9-day-old Mexican wolf puppy at Brookfield Zoo during a health exam prior to being flown to Arizona as part of the U.S. Fish and Wildlife Services’ Mexican Wolf Recovery Program. The puppy and five of its siblings are being cross-fostered with wild Mexican wolf packs to help enhance the genetic diversity of the overall Mexican wolf population.
9005: Dr. Lily Parkinson, a clinical veterinarian for the Chicago Zoological Society, weighs a Mexican wolf puppy during a health exam. Seven puppies were born at Brookfield Zoo on April 27, and six of them were flown to Arizona to be cross-fostered with wild Mexican wolf packs as part of the U.S. Fish and Wildlife Services’ Recovery Program to help enhance the genetic diversity of the overall population.

About the Chicago Zoological Society
The mission of the Chicago Zoological Society is to inspire conservation leadership by connecting people to wildlife and nature. The Chicago Zoological Society is a private nonprofit organization that operates Brookfield Zoo on land owned by the Forest Preserves of Cook County. The Society is known throughout the world for its international role in animal population management and wildlife conservation. Its Center for the Science of Animal Care and Welfare is at the forefront of animal care that strives to discover and implement innovative approaches to zoo animal management. Brookfield Zoo is the first zoo in the world to be awarded the Humane Certified™ certification mark for the care and welfare of its animals, meeting American Humane Association’s rigorous certification standards. The Zoo is also accredited by the Association of Zoos and Aquariums, Alliance of Marine Mammal Parks and Aquariums, and the International Marine Animal Trainers’ Association. Brookfield Zoo is located at 8400 31st Street in Brookfield, Illinois, between the Stevenson (I-55) and Eisenhower (I-290) expressways and also is accessible via the Tri-State Tollway (I-294), Metra commuter line, and CTA and PACE bus service. For further information, visit



Sondra Katzen
Director of Public Relations
Office: 708-688-8351
Cell Phone: 708-903-2071


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