Historic cross-fostering involves wolves from here

This photo shows Wesley shortly after his release in  April 2013 into a large acclimation pen in the Apache-Sitgreaves National Forest in eastern Arizona. The photo was taken by Executive Director Ginny Busch. Several members of the Endangered Wolf Center staff were present.

Wesley shortly after his release in April 2013 into the acclimation pen. Photo taken by Executive Director Ginny Busch. Several members of the Endangered Wolf Center staff were present.

Ernesta runs from her crate into the acclimation pen in April 2013.

Ernesta runs from her crate into the acclimation pen in April 2013 in the Apache-Sitgreaves National Forest in eastern Arizona  .

ST. LOUIS – Ernesta and Welsey, two Mexican wolves from the Endangered Center in Eureka, Mo., are playing key roles in historic events now taking place.

The Mexican Wolf Interagency Field Team has conducted the first cross-fostering of Mexican wolf pups in the wild, the U.S. Fish and Wildlife Service and Arizona Game and Fish Department announced May 21, 2014. Cross-fostering is a technique to move very young pups from one litter into a different, similar-age litter with the hope that the receiving pack will raise them as their own.

Two pups from the six-pup litter of Ernesta (F1126), a recently released Coronado pack female, were transplanted into the three-pup litter of the Dark Canyon pack female (F923) on the Gila National Forest in New Mexico on May 15, the agencies announced. Both litters are approximately two weeks old.

This cross-fostering attempt was undertaken to introduce genetically desirable pups into the litter of an experienced female and wild-proven pack, the agencies explained. Cross-fostering has been successfully employed in the east coast red wolf recovery program. Ernesta and her offspring are descendants of a genetically underrepresented lineage in the Mexican wolf wild population. F923 is a 9-year-old female that has successfully reared pups in a pack that demonstrates favorable wild behavior.

“We will adaptively manage these wolves in order to produce a population that is not measured by numbers alone, but by genetic robustness, desirable wild behavior and survivability,” said Benjamin Tuggle, the U.S. Fish and Wildlife Service’s Southwest Regional Director. “Cross-fostering is just one of the management tools we can use to improve the genetic health of the wild population.”

Ernesta was born in 2008 at the Endangered Wolf Center and raised there before moving to the Brookfield Zoo in Chicago. Her mother Anna, still lives at the Center.

Ernesta was among two pairs of wolves released by the Mexican Wolf Interagency Field Team in April in Arizona. She and her mate were identified as the Coronado pack. Shortly after her April 9 release into the wild, the pregnant wolf and her mate M1249 separated, possibly as a result of an encounter with an already existing pack. M1249 has since been located back in his original territory. Ernesta settled in an area south of the release site, and the field team maintained a food cache for her in the area. Ernesta established a den and delivered pups around May 5.

She has no previous experience in the wild, and with no mate to assist her with hunting and rearing the pups, the field team determined that the pups would not likely survive in the wild based on previous occurrences of inexperienced lone females being unsuccessful in raising pups in the wild.

On May 15, the Interagency Field Team retrieved Ernesta and her pups. While two pups were cross-fostered to the Dark Canyon pack, the remaining four pups were transported with her to the Sevilleta Wolf Management Facility in New Mexico. On May 17, the Service introduced Ernesta and her pups to her former mate, Wesley (M1051), to enable these pups to be reared by both an adult male and female and provide a cohesive pack for translocation to the wild.

If this newly formed pack continues to do well, it is slated for translocation into the Gila Wilderness Area in New Mexico early this summer.

The reintroduction is collaborative effort of the U.S. Fish and Wildlife Service, Arizona Game and Fish Department, White Mountain Apache Tribe, USDA Forest Service, USDA Animal and Plant Health Inspection Service–Wildlife Services, and several participating counties in Arizona.

The Endangered Wolf Center serves as the cornerstone of the U.S. Fish and Wildlife Services Mexican wolf reintroduction programs.

At one time, only five Mexican wolves existed in the wild. When those five were captured between 1977 and 1980 and brought into managed care, the species was declared extinct in the wild. The first release of wolves from managed care facilities took place in March 1998. Nine of the 11 wolves in that release were from the Endangered Wolf Center.

The latest census of Mexican wolves conducted in 2013 found 83 of them in the wild.


For more information contact:

Regina Mossotti, Endangered Wolf Center, Director of Animal Care and Conservation, at 636-938-5900 or [email protected]


The item above is based on a news release issued May 21, 2014, by the U.S. Fish and Wildlife Service and the Arizona Game and Fish Department.



Show your love for wolves and get 10% off your membership through February! Adoptable Animals