Accredited Zoos Play a Critical Conservation Role in Survival for Imperiled Species
Connecticut’s Beardsley Zoo in Bridgeport, Conn., one of 57 zoos nationwide with Mexican grey wolves in its collection, recently welcomed Dr. Cheryl Asa as part of the Association of Zoos and Aquariums’ Mexican Wolf Recovery Program. The AZA’s Species Survival Plan―manages the bi-national recovery program with the U.S. Fish and Wildlife Service (USFWS) and Mexican counterparts.
Asa, a reproduction advisor in the recovery program and affiliate scientist of the Saint Louis Zoo in St. Louis, Mo., came to Connecticut’s Beardsley Zoo with her colleagues Rebecca Bose and Louisa Gagliardi from the Wolf Conservation Center in South Salem, N.Y., to collect semen samples from the Zoo’s two male Mexican grey wolves.
Declared extinct in the wild in 1980, the Mexican grey wolf, also known as “el lobo,” faces ongoing genetic threats to its survival. The Mexican grey wolf population comes from just seven original “founders,” wolves captured by three private breeders before their numbers plummeted. Genetic diversity suffered as those separate pairs of wolves were inbred.
Zoos in the U.S. and Mexico acquired the wolves and initiated a recovery program for the species. They have created a genetically healthier population through genetic analysis and careful breeding.
“Our Mexican grey wolves are ambassadors for their species. Unless people can see and appreciate these animals, there is little support to protect them in the wild. In accredited zoos, they are provided with professional care and often live much longer lives, providing breeding opportunities to help sustain their numbers,” said Zoo Director, Gregg Dancho. “We’re proud to do our part to help save this important species, one of the most endangered mammals in the country.”
In 1990, USFWS designated the Saint Louis Zoo Research Department as the headquarters for a frozen semen bank responsible for evaluating fertility in individual males. Males are chosen for banking each year based on their genetic value to the population and their location around the country.
“The semen collection is important because it gives us the ability to add a male’s genes to the population even after he dies,” said Asa. “We can accomplish genetic management without physically moving wolves, which can disrupt pair bonds in a monogamous species that mates for life.”
USFWS estimates that there were 241 Mexican grey wolves in the wild at the end of 2022, but the population’s numbers remain below recovery objectives, and genetic management remains critical. The population in zoos is more genetically balanced than in the wild, making it essential to monitor and release wolves with genes that can help restore genetic balance.
Wolves contribute to the environment’s health by keeping deer, elk, and javelina populations in check, preventing these animals from population growth that results in overgrazing and the destruction of habitat that other species depend upon.
More than one million wolves were killed in the U.S. between 1850 and 1900. In 1907, a call was made for the extinction of the entire species. Throughout the wolf’s history, they have been hunted and reviled due to fear and misunderstanding. In addition to the Mexican grey wolf population’s genetic diversity issue, the wolves face inadequate recovery habitat in the wild and conflict with humans when wolves wander past their restricted boundaries.
Photo Credit: Jack Bradley
Edited by Sarah Gilsoul, a writer and communications program assistant at AZA.
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