Endangered Mexican Gray Wolf Leaves Brookfield Zoo to Prepare For Reintroduction to Native Habitat

Ernesta, an endangered female Mexican gray wolf, recently left Chicago Zoological Society – Brookfield Zoo to prepare for reintroduction to the wild. Photo by Jim Schulz/Chicago Zoological Society


Ernesta, an endangered female Mexican gray wolf, will soon be making great strides for the future of her species.

With only 58 Mexican gray wolves living in the wild in New Mexico and Arizona, the 4 ½-year-old wolf left Brookfield Zoo, which is managed by the Chicago Zoological Society, to prepare for reintroduction to her species’ native range.

On October 27, Ernesta relocated to the U.S. Fish & Wildlife Service’s (USFWS) Sevilleta Wolf Management Facility at the Sevilleta National Wildlife Refuge near Socorro, New Mexico. At the facility, she will then choose a mate to be paired with for potential release. They will receive survival skills conditioning through a pre-release “boot camp” to prepare them for life in the wild.

“Just a few decades ago, the Association of Zoos and Aquariums’ (AZA) Mexican Gray Wolf Species Survival Plan® (SSP) was put in place to save the wolves from absolute extinction,” said Joan Daniels Tantillo, associate curator of mammals for the Chicago Zoological Society. “Ernesta’s potential transfer into the wild is an important step to help foster genetic diversity within the reintroduced population to allow this species to survive.”

The purpose of the pre-release conditioning is to make sure wolves are good candidate for re-introduction to their native range. Wolf biologists with the USFWS wildlife refuge will observe Ernesta as they slowly transition her to feedings that mimic the typical wolf food patterns found in the wild. She will transition to eating native prey (including road-killed deer and elk) and experience conditions that imitate their natural eating patterns in which prey kills happen only every several days. She will also be subjected to conditioned taste aversion to avoid eating beef so that if she is reintroduced into the wild, she does not cross paths with cows and ranchers.

While Ernesta may have some skills to learn at boot camp, her natural wolf behaviors have been encouraged since her first day at Brookfield Zoo and will help ensure a safe and healthy transition for her potential release to the wild.

Regenstein Wolf Woods, the wolf exhibit at Brookfield Zoo, includes design implementations to cultivate these behaviors, including:

  • Wolves socialize only with each other. Keepers do not interact directly with wolves.
  • Wolves receive native prey species such as elk hide, bison meat, and whole prey items.
  • Climbing logs, a pool, heated rocks, and loose dirt encourage natural behaviors like playing, lounging, and digging.
  • Dens and tunnels are the size, shape, slope, and length of those in the wild, and there is space for the wolves to dig their own dens.
  • Buildings blend in with the natural surroundings so that the wolves don’t associate manmade structures with shelter or food.

“We are committed to the highest level of animal care, and Regenstein Wolf Woods ensures that wolves participating in the release program will be successful in their transition into the wild,” Daniels said.

Accompanying Ernesta to the Sevilleta Wolf Management Facility were two potential mate choices from the Endangered Wolf Center in Eureka, Missouri, where Ernesta was born in April 2008 before coming to Brookfield Zoo in 2010 with her litter mates (three brothers and four sisters). The rest of her pack remains at Brookfield Zoo.

The flight to New Mexico was sponsored by LightHawk, a volunteer pilot organization that sponsors flights of animals partaking in reintroduction programs. LightHawk also participates in other conservation-related monitoring in North America to provide aerial views of the land and assist in environmental protection.

Ernesta arrives at the U.S. Fish & Wildlife Service’s (USFWS) Sevilleta Wolf Management Facility at the Sevilleta National Wildlife Refuge in New Mexico. Photo by Tom Buckley/USFWS

Mexican gray wolves are part of a breeding program that is managed by the USFWS in coordination with the AZA under its Species Survival Plan® (SSP) and the Mexican Technical Advisory Subcommittee for the Conservation of Mexican Gray Wolves.

Mexican gray wolves are the rarest and most genetically distinct subspecies of the North American gray wolves. The USFWS first listed the species as endangered on the Endangered Species List in 1976. There are 283 Mexican wolves living in 52 institutions across the United States. The 2011 census recorded a minimum count of 58 individuals in the wild in New Mexico and Arizona, and in October 2011, five wolves were released for the first time in the northern Mexican state of Sonora.

If all goes well during boot camp, Ernesta and her selected mate will be reintroduced to their native range sometime in the spring of 2013.

Contributing writer: Nina Martines/Chicago Zoological Society


Jennifer Fields

This entry was posted in Brookfield Zoo, Conservation, Wildlife, Wolves, Wolves, Zoo. Bookmark the permalink.

One Response to Endangered Mexican Gray Wolf Leaves Brookfield Zoo to Prepare For Reintroduction to Native Habitat

  1. ladyofthezoos says:

    So excited for this species!


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