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Wisconsin Natural Resources magazine

Wisconsin Natural Resources magazine

An ultralight plane piloted by Operation Migration personnel leads the way for these young whoopers. © Whooping Crane Eastern Partnership
An ultralight plane piloted by Operation Migration personnel leads the way for young whoopers.

© Whooping Crane Eastern Partnership

April 2002

On a wing and a prayer

An airborne metal "mom" may save whooping cranes from extinction by teaching young cranes how to fly – and migrate.

Robert J. Manwell

Lift-off! | A quick whooper history
The Wisconsin choice | Migration 101
Staying wild, staying safe | Why whooper recovery is important
Whooping crane vitals | Whooping crane partners

At the edge of Necedah National Wildlife Refuge stands an iron sculpture, "Freedom, Liberty and Courage," that depicts three tall birds – whooping cranes – that were once part of this great wetland. The birds disappeared from this place over 123 years ago and very nearly disappeared from the face of the earth altogether.

After the last glacier, when grass was the dominant vegetation, cranes ranged from coast to coast and from the arctic to central Mexico. In time, forests replaced grassland and water tables subsided, shrinking crane habitat. Some cranes such as the sandhill adapted to a less watery environment, while the whooping crane didn't change and stayed within evernarrowing confines.

Settlers, pushing the frontier west, found the large birds to be a free, welcome addition to their table fare. Milliners found the large white feathers fashionable. In a vast land of great resources, everyone thought there would always be whooping cranes around some place. No one ever imagined how soon we would run out of some places – and whooping cranes.

But for this species, on a cold fall morning in October 2001, a new beginning was about to unfold.

Lift-off!

Fifty or so people stood on the edge of the Necedah marsh that day, clustered in small groups, hands stuck deep in pockets to warm cold fingers. Their first clue that history was in the making was the drone of small aircraft engines. Approaching from the south, three tiny yellow aircraft came into view. One dipped low and landed, briefly disappearing behind the intervening vegetation.

It quickly rose into the air again, but this time it was not alone. Stretched out in two loose chevrons from the aircraft's wingtips were eight young whooping cranes. These were the first wild whoopers to fly over Wisconsin in 123 years. They were embarking on the first leg of a 48-day, 1,218-mile journey behind the slow-flying ultralight airplane driven by a costumed pilot they thought of as a parent.

A quick whooper history

Available accounts of whooping crane populations put their numbers at somewhere between 700 and 1,400 in the mid-1800s. Whooping cranes never numbered very many as far as we know. They are reclusive and shy, females lay just two eggs each year if they lay eggs at all. Their nests are vulnerable to predators and they do not adapt well to much of what people call "progress": the draining of wetlands, the plowing of prairies, the raising of tall buildings, towers and powerlines. What is clear is that by the 1940s, only about 15 to 20 whooping cranes remained in the world.

This small flock showed up every fall at what is now the Aransas National Wildlife Refuge on the Gulf Coast of Texas about 75 miles north of Corpus Christi. What wasn't known was where they disappeared to each spring.

In 1946, the National Audubon Society appointed researcher Robert Porter Allen to study the life history of whooping cranes on the Texas wintering grounds, trace their migration route and search for their nesting area.

The whoopers' breeding ground finally was revealed in 1954, when a fire crew flying over Canada's Wood Buffalo National Park sighted three cranes in the air near the Hay River. One year later, the nesting area was confirmed when Allen located a whooper nest.

From this meager beginning, concerned biologists began the slow task of rebuilding the population of the largest of all North American waterfowl. Out of this effort grew the present day International Whooping Crane Recovery Team – a group of Canadian and U.S. wildlife managers dedicated to the recovery of the endangered species.

The Endangered Species Act requires that a recovery plan be created to improve the population health of the species. The plan devised by the recovery team calls for establishing geographically separate flocks of wild whooping cranes, so that if disease, bad weather or other natural or human-caused disaster affects one flock, the remaining flocks can continue the work of survival.

Step one was to place a non-migrating flock of 14 birds in central Florida at Kissimmee Prairie, managed by the Florida Department of Environmental Protection. That original 1993 flock now numbers 75 birds and new birds are added each year. A pair of adults from this flock has successfully nested and produced a pair of chicks, but both were lost to predators. Hope remains high that this pair will mate again and others in the flock will follow.

The Wisconsin choice

Setting up a non-migratory flock was important and a great accomplishment in the preservation of the species. But whooping cranes are migratory birds and the difficulty of establishing a migrating flock was much greater. Where would they nest? Where would they winter? How would they learn a safe migration route? This was new ground in the practice of wildlife management, requiring new ideas, new techniques and new approaches.

A search to find suitable northern nesting habitat started. Whoopers are reclusive and require large areas of shallow wetland habitat with average water depths of 24 inches or less. They need sufficient food sources, reasonable protection from predators, and water relatively free of pollutants, lead shot and avian disease.

Biological criteria weren't the only items on the list. The local human population needed to be receptive to having an endangered species reintroduced to their environment, and public access to the rearing, flight training and nesting sites had to be controlled to protect the new flock.

Three Wisconsin sites offered promise: Crex Meadows, Horicon National Wildlife Refuge and the adjoining state Horicon Wildlife Area, and Necedah National Wildlife Refuge adjoined by the Meadow Valley State Wildlife Area. In September 1999, the Whooping Crane Recovery Team decided on Necedah. At the same time, the Whooping Crane Eastern Partnership (WCEP) was formed to carry out the project. A group of nine state and federal agencies, private nonprofit organizations and two fundraising foundations, "Wee-Sep" quickly established extended partnerships with 20 eastern states, two Canadian provinces and the Eastern and Mississippi Flyway Councils to cover all the ground a growing whooping crane population might one day visit.

Whooping crane partners
The Whooping Crane Eastern Partnership consists of representatives from: International Crane Foundation,Whooping Crane Recovery Team, National Fish and Wildlife Foundation, Natural Resources Foundation of Wisconsin, Operation Migration, Inc., U.S. Fish and Wildlife Service, U.S. Geological Survey – Patuxent Wildlife Research Center, U.S. Geological Survey – Wildlife Health Center in Madison, Wis., and the Wisconsin Department of Natural Resources.

Visit: Whooping Crane Eastern Partnership

For teachers: Journey North

Migration 101

Eggs for the Wisconsin flock came from captive rearing stock at the U.S. Geological Survey's Patuxent Wildlife Research Center in Maryland. The eggs were hatched at Patuxent and when the chicks were old enough to travel they were flown – via donated charter plane – to Wisconsin for training and imprinting on the Necedah surroundings to ensure they would return to Necedah in the spring.

In the wild, juvenile whooping cranes learn to migrate from adults in their family group. But there are no adult whoopers for young cranes to learn from in Wisconsin. Operation Migration, a nonprofit Canadian-U.S. organization dedicated to exploring the possibilities of human-led migrations, has been developing techniques to train birds to follow ultralight airplanes.

The organization's co-founders, William Lishman and Joe Duff have flown with Canada geese, trumpeter swans, sandhill cranes and now, whooping cranes. Some readers may remember seeing the movie Fly Away Home, which was based on Lishman's work.

Key to the success of the technique is the young crane's instinct to imprint on the first large object it sees upon hatching – in this case, a crane-head hand puppet, a white-costumed handler and the aircraft.

Like other migratory birds, whooping cranes are able to remember and navigate on their own after first being shown the route. The recovery migration route was chosen to closely follow routes used by wild sandhill cranes, but with slight detours to avoid large cities like Chicago and Atlanta.

Staying wild, staying safe

Training began before hatching, when recordings of the aircraft's motor were played in the incubator as soon as the chicks began to pip or tap on the inside of their shells with their bills. After hatching, the chicks were fed and nurtured with the hand puppet, then gradually introduced to the costumed handler and to the aircraft in an outside pen.

Once wild animals become accustomed to humans, they tend to lose an important survival skill – human avoidance. The whooping cranes in this project were raised according to a strict isolation protocol. They never experienced an uncostumed human and the handlers never spoke within hearing distance of the birds. Recorded crane calls were played to accustom the cranes to their own "language," to calm the birds when frightened, and to entice them to follow the handler or the aircraft.

At about six weeks of age, the juvenile birds were put into individual shipping cages and flown to Wisconsin where they were checked by veterinarians and released into an outdoor pen. Costumed handlers conducted all the work in complete silence.

The whooper chick, imprinted from birth on the adult crane puppet, learns to eat with a little help from 'mom.' © Whooping Crane Eastern Partnership
The whooper chick, imprinted from birth on the adult crane puppet, learns to eat with a little help from 'mom.'

© Whooping Crane Eastern Partnership

Over the next weeks the birds grew rapidly and began to develop flight feathers. Each day, just after sunrise, they were let out onto a flat grassy area in front of the pen where an ultralight airplane sat, waiting. At first, the cranes walked slowly behind the airplane, picking up tasty mealworms dropped by the pilot from a crane puppet. Soon, the birds were running and hopping as the aircraft taxied faster. When flight feathers were developed enough to create lift, the young cranes ran, set their wings and glided a few feet until one day, they left the ground in full flight.

The early flights were very short, lasting only a few minutes. Cranes normally soar; they ride thermals, or upwellings of warm air, to great heights, then set their wings and glide for miles. Soaring uses little energy compared to flap-flying like a crow or songbird. For a bird as large as a crane, flap-flying is very tiring; it takes many weeks to build up flight muscles and endurance.

Following an ultralight, the cranes in front of the line can "surf" on the "wake" of air spilling off the aircraft's wing; the birds farther back must work harder. The wake forms best in still morning air. With a tailwind, it's possible to cover 80 to 90 miles a day on migration. The average flight for this first fall migration was 48.7 miles. With a headwind, which breaks up the wake, the pilots and birds usually remain on the ground. In 2001, poor weather and headwinds grounded the migration for 23 days out of 48.

The cranes arrived at Florida's Chassahowitzka National Wildlife Refuge on December 3 – 1,218 miles from their starting point in Wisconsin. Researchers anticipate the whoopers will return to Necedah on their own this spring. The sandhill cranes led down to Florida by ultralight the previous year returned on their own to Necedah to within 100 yards of their training area.

Why whooper recovery is important

The Whooping Crane Recovery Team aims to restore two flocks of at least 25 breeding pairs in addition to the existing Wood Buffalo-Aransas migratory flock. This would bring the population to a level where whooping cranes could be downlisted from endangered to threatened under the Endangered Species Act. In Wisconsin, biologists feel that it will take a total population of about 125 birds to provide 25 nesting pairs. Ultralight migrations may continue for the next four to five years as the flock increases. After that, it is expected that young of the year will learn the migration route from adults.

Why is whooping crane recovery important? One reason is that humanity has an obligation to practice wise stewardship of our soil, air, waters, flora and wildlife. We have the capacity to plan for the future of our natural world. This project is a significant step toward slowing the disturbing trend in species extinction.

Wisconsin has made great progress in returning extirpated species to the land. Completing this project will return one more piece of Wisconsin's natural heritage to the landscape, and will add to the list of things that make Wisconsin a great place to live. There is excitement in anticipating the day citizens or their children will be able to look skyward at the sound of a whooper's bugle and see a group of these remarkable birds fly overhead.

Robert J. Manwell is the public affairs manager for DNR's endangered resources, parks and wildlife programs as well as Outreach Team Leader for the Whooping Crane Eastern Partnership.

Whooping crane vitals
  • Species: Grus americana
  • Height: up to five feet
  • Weight: males average 16 pounds; females, 14 pounds
  • Wingspan: up to eight feet
  • Life span: up to 25 years in the wild
  • Color: juveniles – ruddy brown with some whitish tinges and black wing tips, eyes blue. adults – feathers white except for black wing tips, eyes yellow, bill yellow, legs black, feet black, red patch on top of head

  • Primary threats: disease, power lines, loss of wetlands due to climate change and drainage

  • Call: many vocalizations, most prominent is probably the unison call, which is audible for up to two miles (listen to the calls at Whooping Crane Eastern Partnership.)

  • Reproduction: Cranes pair for life and mate at about four to five years of age. Female usually lays two eggs, only one of which survives to fledging stage. Nests are built in shallow wetlands from surrounding vegetation.