Whooping cranes back from the brink of extinction.
The U.S. Fish and Wildlife Service (Service) has had tremendous support from many partners in efforts to restore this majestic bird in the wild. Partnerships with the International Crane Foundation, the U.S. Geological Survey Patuxent Wildlife Research Center, Operation Migration (OM), the Wisconsin Department of Natural Resources (WDNR), the Louisiana Department of Wildlife and Fisheries (LDWF), and the Florida Fish and Wildlife Conservation Commission (FFWCC) have all played a vital role in moving this species towards recovery.
Historically, whooping cranes were wide-ranging in North America, occurring from central Canada south to Mexico and from Utah to the Atlantic coast and numbering from 15,000 to 20,000 individuals. Habitat loss caused by conversion of wetlands and grasslands to agricultural fields, coupled with unregulated hunting and specimen collection, devastated whooping crane populations. By 1941, only 21 remained in the world--six in a non-migratory population at White Lake in Louisiana and 15 at Aransas National Wildlife Refuge (NWR) in Texas. By 1947, there was only one surviving crane from the White Lake population. It was captured and transferred to the Aransas population in 1950.
Hope for the species' survival rested in the single remaining flock wintering at Aransas. The breeding grounds for this flock were unknown until 1954, when a fire crew flying over Wood Buffalo National Park in Canada spotted the birds there. Following this discovery, the Whooping Crane Recovery Team--a team composed of ten crane experts from the U.S. and Canada--began collecting eggs from Wood Buffalo National Park to start a captive breeding program. Egg collection began in 1967, the same year the species was federally listed as threatened in the U.S. (later changed to endangered status in 1970 after continued population decline). The successful captive breeding program, in conjunction with state, federal and international efforts to better protect the Aransas/Wood Buffalo migratory flock and its habitat, resulted in a dramatic change of fortunes for this rare, majestic bird. Today, nearly 280 cranes make up the population that migrates between Texas and Canada each year.
For insurance against potentially catastrophic events such as disease outbreak or natural disaster, which could eliminate the species, the recovery team attempted to establish a second self-sustaining migratory flock in southeastern Idaho in 1975, and a non-migratory flock in Kissimmee Prairie, Florida in 1993. Unfortunately, both programs were discontinued after they were only minimally successful.
Efforts to establish a migratory population of whooping cranes in the eastern U.S. began in 1999, with the formation of the Whooping Crane Eastern Partnership (WCEP). Starting in 2001, captive-reared chicks were released at Necedah NWR in central Wisconsin and trained to follow an ultralight aircraft in preparation for a fall migration to wintering grounds at Chassahowitzka NWR in Florida. Every year since 2001, juvenile whooping cranes have followed OM pilots south to Florida, and have successfully migrated back to Wisconsin the following spring.
The ultralight-led migration hit an unexpected roadblock earlier this year, however, when the Federal Aviation Administration (FAA) grounded the migration flight in Franklin County, Alabama over an issue regarding pilot licensing. Fortunately, FAA granted a one-time waiver allowing an OM pilot to continue the flight, but the 9 juvenile whooping cranes were not interested in migrating further south. In February, the whooping cranes were captured and moved to Alabama's Wheeler NWR, which has become their new winter home. However, efforts to establish an eastern migratory population of whooping cranes are working well, and there are now 112 cranes in this population.
The reintroduction of whooping cranes to the White Lake Wetlands Conservation Area in Louisiana marks the fourth reintroduction of the species into the wild, and the only reintroduction of the species into an area where it historically occurred. The Service, with help from LDWF, is working to establish, manage, and monitor this population. The first cohort, or group, of 10 juvenile whooping cranes arrived from Patuxent Wildlife Research Center in February 2011. These cranes were introduced to their new home using the soft-release technique and are acclimating quickly to their new home. A second cohort of 16 juveniles arrived at White Lake in December 2011. "Overall this second cohort is doing great, and we're thrilled to have more whooping cranes that now call Louisiana home," says Sara Zimorski, a biologist with LDWF. New cohorts of juveniles will continue to be released at the site until the population is able to sustain itself.
The efforts of many partners over the last 60 years have helped the species rebound from a low of 21 individuals in 1941 to 599 individuals in North America today. While this magnificent bird is still threatened by habitat loss and degradation, illegal shooting, predation, and collisions with power lines, the reestablishment of the White Lake population in Louisiana will help to further safeguard the species from the risk of extinction.
Editor's note: Additional information on whooping crane reintroduction efforts can be found at the Louisiana Ecological Services Field Office, the North Florida Ecological Services Field Office, and the Louisiana Department of Wildlife and Fisheries websites.
Nikki Lamp, a biologist at the Service's Southeast Regional Office, can be reached at email@example.com or 404-679-7118.
Please note: Illustration(s) are not available due to copyright restrictions.
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|Publication:||Endangered Species Bulletin|
|Date:||Jun 22, 2012|
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