Seven Mexican wolf pups born at Brookfield Zoo Chicago on April 27 were placed into two wild Mexican wolf dens in New Mexico on May 7 and 8 as part of the Mexican Wolf Recovery Program. The robust multi-agency conservation effort of fostering zoo-born pups in wild dens has been a successful strategy that continues to bolster the subspecies’ population in the southwest United States-Arizona and New Mexico-as well as in Mexico.
At 10 days old, the pups-six males and one female-were fed and kept warm by two animal care specialists and a veterinary technician from Brookfield Zoo Chicago during their flight to New Mexico. Air transportation was provided 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.
Upon arrival, members of the Mexican Wolf Interagency Field Team stealthily covered the pups in the scent of the similarly aged wild pups already in the den to ensure they all smelled the same. Before being placed back in the den, all the pups were swabbed for DNA and given studbook numbers. The biologists then monitored the radio-collared mothers to verify that each one returned to her den and successfully accepted the zoo-born pups as her own. The proven process is known as fostering-transferring zoo-born wolf pups into the dens of wild packs to improve the genetic diversity of the wild population. This year marked a milestone in the Program’s wolf pup fostering-a pup born at another facility was the 100th to be placed with a wild pack since fostering began in 2014.
“As part of our ongoing collaboration in the Program, we were thrilled to once again be able to contribute to this year’s fostering of pups,” said Mark Wanner, associate vice present of animal care and conservation at the Zoo. “We are extremely proud to be a part of this effort and share its success with our guests and hopefully inspire them to also care about these magnificent creatures that play an important role in the ecosystem.”
Two additional female pups born in the litter are remaining at Brookfield Zoo Chicago. The pups are still in a den with their mother, but guests will be able to see them in the coming weeks at the Regenstein Wolf Woods habitat along with their parents, 5-year-old Vivilette and 11-year-old Amigo, as well as Ahote, their older brother born in 2023.
Partners in the Mexican Wolf Recovery Program include, U.S. Fish and Wildlife Service, Arizona Game and Fish Department, New Mexico Department of Game and Fish, U.S. Department of Agriculture (USDA) Forest Service, USDA APHIS Wildlife Services, White Mountain Apache Tribe, Bureau of Land Management, National Park Service, and facilities, including Brookfield Zoo Chicago, that are involved in the Association of Zoos and Aquariums’ Saving Animals From Extinction (SAFE) Mexican Wolf program. Through SAFE, accredited zoos and their partners work collectively to help save the Mexican wolf through education, scientific study, fieldwork, public awareness, and action. Brookfield Zoo Chicago has participated in the Program since 2003, supporting successful fostering, cross-fostering-pups from the Zoo were placed with a wild pack and pups from a wild pack were place at the Zoo, and an adult from the Zoo being released to the wild and successfully raising a litter.
“With the help of our amazing SAFE partners, including Brookfield Zoo Chicago, we fostered a record number of Mexican wolf pups into the wild this year,” said Maggie Dwire, Mexican Wolf Recovery Program deputy coordinator for the U.S. Fish and Wildlife Service. “Fostering is a truly remarkable conservation achievement, demonstrating what can be accomplished when partners come together under a unified goal to recover endangered wildlife.”
The Mexican wolf is the rarest and most genetically distinct subspecies of gray wolf in North America. Approximately 4,000 individuals 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, resulted from antipredator campaigns in the United States and Mexico. According to the 2023 population census conducted by USFWS, wild Mexican wolf numbers saw another year of growth. The increase-a minimum of 257 Mexican wolves distributed across Arizona and New Mexico-marks the eighth consecutive year of population growth, which is the longest continuous streak since recovery efforts began.
To learn more about Brookfield Zoo Chicago’s conservation work with Mexican wolves and other species, visit brookfieldzoo.org.