Josephine Marcotty, Star Tribune

Published January 4, 2004 WOLV04

Rosalyn is the alpha female wolf in her pack, a position she has won through many bloody battles with her sisters and daughters in the pens at the Wildlife Science Center in Forest Lake.

But she showed none of that ferocity Saturday as she paced, trembling and fearful, in a holding area. A few humans in Carhartt overalls reached out to soothe her as a sedative took effect. Rosalyn's golden eyes slowly glazed over, and her long legs gave way as she sank to the concrete.

It was time for her birth-control implant.

She is one of seven wolves at the center that will be test subjects for an experimental drug that could help control captive populations and bring genetic diversity to nearly extinct subspecies of the gray wolf that are being reintroduced to the wild elsewhere in the country.

"Species reproduce quite well in captivity, and we keep them alive much longer than in the old days," said Cheryl Asa, director of research at the St. Louis Zoo, who is heading the wolf study. "It's getting to be a problem."

The nonprofit wildlife center is home to 49 wolves and doesn't have room for any more.

The center, which is at the Carlos Avery Wildlife Management Area, is also home to lynx, bears, raptors, bobcats, foxes and two New Guinea wild dogs from a now-defunct animal show at the Mall of America. There aren't many birth-control options for wolves in captivity. Fertile females must either be temporarily separated from their lifelong mates, which is difficult for both the wolves and their handlers, or given a hormonal implant that fools their bodies into thinking they are pregnant. But inserting it requires a surgical incision, and false pregnancies can lead to long-term health problems, said Peggy Callahan, a wolf expert and executive director of the wildlife center.

So Callahan jumped at the chance to help Asa with her research on the new drug, another type of coated implant.

If it works, the new birth-control implant would be a huge advance, Callahan said, because it's inserted with a needle instead of through an incision, and it suppresses ovulation, resulting in fewer health risks for the animal.

One wolf at a time

Rosalyn, who Callahan said is named after a "tough, gnarly" character from the TV show "Northern Exposure," was the first to get the implant Saturday morning.

After the sedative did its job, Callahan and other staff members from the center carried her inside on a blanket. They pulled a muzzle over her nose and eyes, weighed her by hanging her from a hand-held scale and draped her unconscious body over a table.

Rosalyn was born at the center about six years ago. Her mother was a criminal from Alaska, sent to the center probably because she'd been killing dogs, Callahan said. Most of the wolves there are criminals, political prisoners or their offspring, Callahan said.

Rosalyn weighed in at 105 pounds. Only wolves raised in luxurious captivity grow as large or as old as her, Callahan said.

Mark Beckel, Callahan's husband and fellow wolf handler, bared a patch of skin between Rosalyn's shoulder blades and inserted the drug-coated plastic implant with a large needle. Within a few minutes, the sedative began wearing off and Rosalyn's ears twitched. She was lifted into a steel crate where she could come out of the anesthesia safe from the cold and any pack members that might try to fight her for her alpha role while she was vulnerable.

Rosalyn's sister, Mariah, was next. No one was sure whether she'd been named after the wind or the rock star. She was easily captured when a line of humans snaked across the one-third-acre pen and slowly directed her toward the gate to the holding area. The humans stepped over bloody chunks of frozen deer carcass -- roadkill used to feed the wolves a natural diet -- and kept a watchful eye on the rest of the pack as it kept its distance from the humans and their strange behavior.

The third female had no name, though Callahan affectionately referred to her as Miss Trouble. She was big and fast and would never come close to humans, so she had to be caught with a net as she charged at 20 miles per hour through her pen.

Next was Bea, a 9-year-old tundra wolf whose parents came from Alaska. And last were Sheila and Daisy, who came to the center from Canada as pups after their mother was shot.

Later this month, Callahan and her staff will help with the second part of Asa's study, using a quicker-acting dose of the drug to trigger ovulation instead of suppressing it. If it works, Asa said, researchers will be able to artificially impregnate wolves with sperm from males other than mates.

That is especially important for the nearly extinct Mexican and red wolves, subspecies of the gray wolf that have only a few breeding lines and should be more genetically diverse before being reintroduced to the wild.

"The only other way is to break up pairs and move them somewhere else, and we hate doing that," Asa said. "So we have to move genes around without moving animals."

Josephine Marcotty is at marcotty@startribune.com.

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