The male Mexican wolf shot and killed Wednesday at the Minnesota Zoo may have escaped a separate holding area to go after two wolves new to the exhibit, officials said.
The new Mexican wolves from the flooded Dakota Zoo in Bismarck, N.D., moved in a couple of weeks ago, disrupting life for Minnesota's lone wolf, said Tony Fisher, animal collection manager at the Apple Valley zoo.
The local wolf's last companion died six months ago.
Zookeepers had been keeping the new wolves away from the Minnesota-born wolf because of its aggression toward them, Fisher said.
The 8-year-old wolf slipped through a gap in the holding area's fence before jumping an 8-foot fence in a secondary enclosure and running onto a public path. The wolf traveled halfway around the zoo's Northern Trail before zoo staff shot and killed it.
The wolf did not harm any humans.
Last winter's heavy snowfall may have caused gaps in the enclosure's fence, Fisher said. Thursday, zookeepers checked exhibits throughout the facility, especially those outdoors, to ensure that other animals are securely contained. Staff also secured the holding area's fence, where the wolf escaped, by adding more fasteners to it.
"We're looking at things a lot closer," Fisher said.
The secondary enclosure's 8-foot fence seemed high enough when the wolf exhibit was created, he said. Now, the zoo may add a wire-mesh top.
"Animals do surprise us on occasion, and some animals are better athletes ...,"
"I think Hollywood has turned tranquilizers into a miracle drug that instantaneously puts animals to sleep, and it's just not that way," Fisher said. "It's really not a very effective tool for controlling a potentially dangerous animal in a tight situation."
Long-term plans are to convert the Mexican wolf exhibit for other animals. Mexican wolves, which are native to the southwest United States and Mexico, are an endangered species, but Fisher said zoos contain a fairly large population.
About 50 Mexican gray wolves exist in the wild, and about 300 in captivity, according to Mexicanwolves.org. The Minnesota Zoo does not breed that species.
After Wednesday's escape, the zoo was required to notify the U.S. Department of Agriculture, which regulates and monitors facilities according to the animal welfare act.
The federal law ensures that facilities provide animals with veterinary care and adequate-size living spaces, as well as meeting other needs, said Dave Sacks, a USDA spokesperson.
It's standard procedure for the USDA to inspect a zoo after an animal escape, he said. If there are any signs of a violation, the zoo could be investigated and face penalties.
Since 2008, the Minnesota Zoo has undergone four routine inspections by the USDA, with the last occurring in July 2010, records show. The agency found no violations.
Within 30 days of an animal escape, the zoo also has to submit a report to the nonprofit Association of Zoos & Aquariums, which accredits facilities for meeting standards, said spokesperson Steve Feldman. The report will detail how the zoo reacted to the escape and what it learned from it. An accreditation commission will review the report.
However, "it's far too early to tell" whether other zoos should change their exhibits yet because of the wolf escape, Feldman said.