It was just before 5 a.m. and four critically endangered wolves were tucked under a seat on a commercial flight from St. Louis to Arizona.
The Mexican wolf puppies, one of the most endangered subspecies of the gray wolf in the world, sat piled in a carrier at the feet of a conservationist.
She was on a mission along with a team of others to bring the tiny wolves born in captivity at the Endangered Wolf Center in Eureka, about 30 miles southeast of St. Louis, to two different packs of wild wolves in Arizona and New Mexico that might raise them along with their own.
But pulling it off would be a logistical feat.
"The stars, the moon, the planets—everything had to align," said Regina Mossotti, director of animal care and conservation at the Endangered Wolf Center.
For these pups to make it into a wild pack, they needed to be no older than 14 days and born within three days of the wild pups they would be paired with and conservationists had to be able to find and hike to the wild den in time.
"None of us were sleeping much," Mossotti said.
The stakes were high—the Mexican wolf was just recently saved from the brink of extinction, largely through the work of the Endangered Wolf Center. In the last 40 years, the wolves have gone from just seven to about 150 in the wild today.
Phase one: Mating watch
The first pieces of the jigsaw puzzle that is rewilding an endangered wolf pup started to fall in place in February in Eureka.
Groups of volunteers at the wolf center were given the unusual assignment of watching its enclosures in shifts 24/7 to report when the wolves mated.
They marked that a female named Sibi who had been shot before coming to the center was set to give birth after mating with a male, Lazarus.
Using the volunteers' breeding alerts, staff know the female would be due within 60 to 63 days.
They entered the due date into a database monitored by the U.S. Fish and Wildlife Service.
Meanwhile, biologists with the service were tracking the behavior of Mexican wolves in the 7,000-square-mile span known as the Blue Range Wolf Recovery Area in Arizona and New Mexico, where most wild Mexican wolves live today.
The biologists use GPS collars to track the wild wolves and note when they begin circling the den, signaling the birth of a new litter.
Then the matchmaking begins.
The Fish and Wildlife service searched the database of wolf litters born in captivity, looking for one born within three days and with lineages that will add to the genetic diversity of the wild pack. They also need to find a pack with several healthy pups. At least two have to be left in captivity with the parents.
In early April, it started to come together. Five pups where born to the wild Elk Horn Pack in Arizona, six pups were born to the Frieborn Pack in New Mexico, and, in Eureka, Sibi gave birth to seven healthy puppies in captivity.
The match—if they could make it happen—was perfect.
Phase two: Wolves on a plane
Next the conservationists had to transport the young wolves some 1,200 miles from St. Louis County into the wild.
They hoped to go on April 16, but were forced to delay because of 60 mph winds and wildfires.
Still, luck was on their side. The fire turned. The winds slowed, and they were able to leave two days later. The pups were still just 10 days old.
The day began at about 3 a.m. for the wolf fostering team, when they put on headlamps and entered the center's wolf enclosure. With black gloves on their hands, they removed the four pups while avoiding the parents.
They checked the animals' health and packed them for the flight, already feeling nervous, Mossotti said.
"You have these critically endangered, federally-owned, helpless, tiny animals in your hands and it's your job to keep them safe and get them across the country," Mossotti said. "So yeah, there's a lot of pressure."
The wolves hadn't yet opened their eyes or started to make noise, so they sat silent in their carrier as they were passed through TSA and placed under the seat on the three-hour flight.
After they landed, the team boarded a tiny plane from the Arizona Game and Fish Department that Mossotti calls "scary small" and made their way to the Blue Range Recovery Area in search of the wild packs.
Phase three: Finding the den
The conservation team split up to find each den, carrying the pups in backpacks all the way.
Using GPS collars on the wild wolves, they trudged through high-elevation expanses in both Arizona and New Mexico—climbing over trees downed by fire and tracking the wolves to pinpoint the small hole in the ground that marks the den.
Once they spotted the wild litter, the biologists used a bit of trickery.
They needed to make the wild-born pups smell the same as the two born in captivity to trick the parents into raising the new additions.
To do this, biologists rubbed the new pups in the dirt and the urine of their adopted wild siblings. They dotted the wild pups with the formula the center-born pups have been eating. They wore gloves and clothes washed in unscented detergent to avoid leaving a human scent.
And, before too long, they moved away from the pack, hoping nature would be kind to the pups they left behind.
Trail cameras and microchips in the pups will, in time, tell if the small wolves survive. It's gone both ways in the past.
"Unfortunately being wild is hard," Mossotti said. "Things happen: they are fighting for food, there's disease, there's other predators and, unfortunately, they also get shot or trapped. People see them as a threat."
Saved from the brink
This type of work has undoubtedly saved Mexican wolves from extinction. The species was decimated by ranchers who, concerned about their livestock, shot, poisoned or trapped the wolves in the late 1800s.
There was a turning point in 1976, however, when the Mexican wolf was placed on the Endangered Species List, giving the animals federal protection. The U.S. Fish and Wildlife Service began an effort to capture the remaining wolves in the wild.
Only seven were found: six males and one female, Nina.
After failed attempts to breed Nina in captivity, she was brought to the Endangered Wolf Center in Eureka in 1981 with the hopes that its large habitat and seclusion would allow her to breed. And it did.
Since then, the Endangered Wolf Center has taken part in several more landmarks in its effort to save the Mexican wolf: the first of the species raised in captivity were released into the wild in 1998, the first was born through artificial insemination using previously frozen sperm and, in 2015, a wolf born in captivity was fostered into a wild pack.
The recent effort marks the third time the center has been able to complete a fostering and the first time members of one Mexican wolf litter has been fostered with two different wild packs at once.
Fostering has now become part of the official federal recovery plan for the Mexican wolf, but conservationists say more needs to be done.
Mexican wolves are restricted to one 7,000-square-mile recovery area. If they venture out, game wardens relocate then back within the confines.
"They are all packed together," Mossotti said. "So we worry how that might limit the recovery effort. They like to move, one pack can cover 100 square miles."
Hunters worried about competition for game and ranchers have fought efforts to allow the wolves more space, Mossotti said, sitting in an office at the Wolf Center.
But despite these concerns, Mossotti said the wolves actually help the ecosystem, keeping populations of deer and other prey in check and weeding out disease.
As Mossotti was speaking, Lazarus the wolf howled for several long moments in the distance.
"They're misunderstood," Mossotti continued. "They don't want to hurt us, they're scared of us. They just want to survive."
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