The spring of 2020 promised to be a big year for Mexican wolf recovery. Unlike previous years, there would be no limits on the number of wolf pups born in managed care that the state of New Mexico would allow to be placed in wild dens, while Arizona increased their limit, allowing up to 12 placements. Known as “cross-fostering,” the process of placing pups born in managed care into wild dens, is a precise and well-coordinated effort that is executed by dedicated staff from several organizations. The chance to place more pups into the wild than ever before represented an important milestone for one of the most endangered mammals in North America.
The Mexican wolf was eradicated from the wild in both the U.S. and Mexico by the mid-1970s and was listed as endangered under the Endangered Species Act in 1976. In the late 1970s, a managed breeding program—established with only seven founder animals—was created for the species with the goal of one-day releasing Mexican wolves back into the wild. In 1998, the U.S. Fish and Wildlife Service (USFWS) began releasing Mexican wolves from the program into the wild in New Mexico and Arizona.
With such a small number of founders, ensuring the wild population contains enough genetic diversity for long-term persistence is a crucial step in the recovery process. The managed breeding program, organized by the Association of Zoos and Aquariums and AZA-accredited facilities, plays an essential role in Mexican wolf recovery by providing pups for cross-fostering each year. All pups selected for cross-fostering improve the genetic diversity of the wild wolf population.
This year, just a month before whelping began, the United States began closing down due to the COVID-19 pandemic. As many as 18 female Mexican wolves at facilities throughout the country were potentially pregnant with litters available to foster if timing matched with the birth of a wild litter. By April, with commercial flights canceling nationwide and pups at facilities in Eureka, Mo., and Wichita, Kan., needing to be transported to wild dens in Arizona and New Mexico, it was unclear if cross-fostering would happen. Since the Service requested the program intentionally increase breeding among captive wolves to provide a surplus of pups for release through cross-fostering, not fostering would have a domino effect of overcrowding the facilities that would be felt for years to come.
Luckily, six months earlier, the conservation nonprofit LightHawk began working with the Mexican Wolf Species Survival Plan team and the USFWS Mexican Wolf Recovery Team to plan for safer, faster, and more customized flights to transport the pups to join their wild foster mothers. The timing, cabin temperature, and route for these flights were all planned to meet the needs of the pups. LightHawk is the largest environmental flying organization in the country. Working with more than 100 conservation partners, they design strategic flight campaigns to address pressing river, ocean, land, and wildlife problems. With a network of over 300 volunteer pilots, they provide more than 200 flights to advance conservation each year.
LightHawk had already worked with the USFWS for a decade, flying adult wolves to advance Mexican wolf recovery. Over the years, LightHawk has flown 42 wolves, with 24 offspring produced as the result of wolf match-making flights, and 10 wolves eventually placed into the wild. This spring, LightHawk officially joined the pup foster effort.
In April 2020, LightHawk volunteer pilot Mike Schroeder signed-up to fly three pups from the Endangered Wolf Center in Eureka, Mo., and transfer them to the field team in Arizona. The transport required a predawn departure and over 10 hours of flying round trip in his Beechcraft King Air 100 in order to pick up the pups and get them to Arizona in time for them to be fed, checked by a veterinarian, and carefully re-packed into backpacks for the hike out to the wild den.
Fostering needs to occur when the donor litter and recipient litter are each less than 14 days old and born within four-to-six days of one another. Recovery team members know the approximate whelp date for managed litters based on observed breeding behavior. They can also ascertain wild whelp dates based on location data via GPS collars. If the stars align, donor pups are moved to the recipient litter.
Despite all these challenges, the transport was a success and the pups were placed into a wild den with their foster mother within just 12 hours of leaving their mother.
“LightHawk was amazing,” said Nancy Smith, senior zookeeper at Sedgwick County Zoo in Wichita, Kan. “Without their service, the Sedgwick County Zoo would not have been able to participate in cross-fostering this year. They also made it incredibly easy for us by doing all the transporting, and reduced the stress on the pups by getting them to their destination so much faster than we ever could have done otherwise.”
Despite myriad challenges, 20 wolf pups bred in managed care were successfully placed in the wild in the spring of 2020. Seven of these pups flew with LightHawk and 13 others were transported by Arizona Game and Fish and a private donor. This beats the record cross-fostering of 12 Mexican wolf pups in 2019.
This is so important because fostering pups into wild dens is currently the primary way the SSP and USFWS are working to improve the genetic diversity of the wild population. The release of adult Mexican wolves has proven effective–it is how the wild population was originally established–but it is not without complications.
Adult wolves released into the wild may lead to human-wildlife conflict. Having wild parents, with wild experience, raise pups born in managed care allows the pups to learn important survival skills. Additionally, adult wolf releases need to avoid areas already occupied by other wolves to avoid territorial issues. Fostering pups allows for genetically unrelated pups to be placed into an existing wild den in an area where humans are already experienced in dealing with wolves. A significant benefit of fostering is these pups are raised in the wild by experienced wolves, eliminating any nuisance behavior that would normally be associated with the release of adult wolves.
In recent years many commercial airlines have tightened restrictions on transporting wildlife. As AZA member facilities and state and federal agencies face increasing challenges related to flying wildlife, LightHawk is proving to be a critical resource. LightHawk flights support the genetic diversity, managed breeding success, reintroduction into the wild, and care of the managed and wild populations of endangered species.
“I don't think fosters would have happened this year without LightHawk, they provided the momentum and means, that even in a pandemic, allowed us to push conservation efforts forward,” said Regina Mossotti, the AZA Mexican Wolf SSP foster advisor. “Their efforts were incredibly impressive. This was an epic success. Not only did we manage to somehow still foster during a world-wide pandemic, but we broke the record for pups placed into the wild.”
In addition to flying to support species survival, LightHawk flights are also helpful for educating and informing other audiences. Flights are designed for educating and engaging elected officials and the media to support informed decision-making around recovery efforts as well as aiding scientists to locate and monitor species in the wild. Best of all, LightHawk flights are donated at no cost to the conservation partner.
Esther Duke is the western program director for LightHawk.