Tucked away like a secret in the woods between Baltimore and Washington, D.C., the crane man and his subjects whoop it up. He, unassuming and jovial, is eager to show off his feathered friends. They, long-legged, long-necked and beady-eyed, will delight the curious observer, if she is lucky, with a dance that has survived the centuries. With a purr-like contact call, he invites their interaction and they come, like snakes to a charmer, necks reaching, legs in an exaggerated, deliberate high-stepping motion. Almost, almost, they dance for me.
Far Away in the Wild
Far afield from Chesapeake Bay, in the wilds of northern Alberta, Canada, at Wood Buffalo National Park, the worlds last wild colony of whooping cranes nest and breed. These rare cranes are snowbirds. After summering in Canada, they migrate to winter at Aransas National Wildlife Refuge on the Gulf of Texas. Since the 1960s, each nesting pair has sacrificed one egg to scientists like Dr. George Gee, the crane man at Patuxent Wildlife Research Center in Laurel, who hope to establish captive flocks to conserve the gene pool.
The theft is working. In 1941, 15 cranes whooped at Wood Buffalo. Today there are 170.
We take one good egg and leave one good egg in each nest, explains Gee. You hold them up to your cheek and if they are warm, then there is a live chick inside. If an egg collector finds two cold eggs, both are removed and replaced with a warm egg from another nest. The removal of one egg from each nest seems to have increased the number of chicks fledged each fall in Canada, since cranes usually lay two eggs but rarely raise two young. Competition between the chicks is fierce and often leads to death.
Still, 170 whooping cranes is not enough to make a healthy gene pool. With all the wild cranes concentrated in one area, they could be wiped out by disease, natural disaster or human impact. Thats where the cranes strutting their stuff for me at Patuxent Research Refuge enter the picture.
Here at Home, Swelling the Flock
These Maryland whooping cranes are the blue bloods, the purebreds, of the crane world. They are part of a breeding program to conserve specific gene lines and prevent extinction of the species. Some will move to Florida, where theyll join a non-migratory colony. Others will never breed lest they pass along genetic deformities common in cranes scoliosis, which contorts their back and neck, or heart murmurs. As foster parents, theyll make fine imprint models for borrowed chicks.
Whooping cranes of the species Grus americana live only in North America. Our whoopers belong to an ancient family of birds that came into being some 50 million years ago, before whales swam in the seas or primates walked on the land. The whoopers name comes from the noise they make. Their trachea which is something like a French horn extends to five feet long and can project a tune as far as two miles.
The Maryland cranes are the parents and foster parents of seven young birds. The chicks hatched at Patuxent in May and are now making their first migratory odyssey: some 1,200 miles from Wisconsin to Florida. Their trainers hope theyll become the first whooping cranes ever taught by humans to migrate.
The trainers Gee, an avian physiologist; David Ellis, a migration research behaviorist; and 13 others on staff at Patuxent are partners with researchers in Wisconsin and Canada in the Whooping Crane Eastern Partnership, a consortium of government agencies and non-profits, whose shared goal is to establish a flock of migrating whooping cranes.
Like the cranes they foster, these scientists are unique in the world as the only international recovery team. Among the members, Operation Migration, based in Canada, helps reestablish migration routes of endangered trumpeter swans [Getting to Know the New Birds on the Bay: Vol. IX, No. 9: March 1-7] and Canada geese, as featured in the movie Fly Away Home. Last year less-rare cousins, the greater sand hill cranes, passed trial flight. This year is the whoopers turn.
Chicks in Training
photo courtesy of Operation Migration
Crane mama Kathleen OMalley figures she has raised more whooping cranes than anyone else in the world in her 17 years at Patuxent. During chick season March through September her friends and relatives know not to make any plans that include her. The chicks need round-the-clock care, seven days a week.
OMalleys shift usually starts at noon and ends, as any mother knows, when the last chick falls asleep. Sick chicks sometimes keep her working through the night. At first it seems that the only difference between her job as chick mama and mine as mama to two daughters is that she gets paid, at least a little.
But as we chat, more differences surface. While I only dress up for Halloween, Kathleen dresses up like a crane whenever she has contact with the chicks. Rather than singing lullabies, she purrs a crane greeting.
The exception is when she cares for the 10 chicks wholl be trained to migrate. For these chicks, the sound of the human voice is not allowed. During their incubation and after they hatch, they hear only tape recordings of crane calls and sounds of their natural environment. They are allowed no exposure to human-made equipment, with one important exception the noises and companionship of the ultralight aircraft that will eventually lead them to their wintering grounds.
The chicks become so accustomed to the ultralight that eventually, OMalley says, they will follow that thing anywhere.
In the wild, crane chicks like geese and swans follow their parents south on the fall migration. Making a mental map of the route, they return north the following spring on their own. Now humans and ultralights are taking the place of crane parents, safely leading the chicks through their migration.
Gee is excited about a new idea that he and George Sladen of the Trumpeter Swan Migration Project have been kicking around that of flying the cranes along the migration route inside an aircraft rather than behind one. Theyre thinking blimp. From a Plexiglas cage on the bottom of the blimp, the cranes could travel first class, viewing their migration route and learn its landmarks. The blimp would circumvent problems faced by the ultralight aircraft, like vulnerability to poor weather conditions and losses en route.
But for now, the ultralight is mom and dad. At the chicks first exposure, when they are just days old, it is a wingless parent. The babies first get comfortable merely foraging around the ultralight frame or trike. Next they follow in its wake around a circular pen, periodically getting mealworm treats from a crane puppet head mounted to an extension arm on the trike.
In the center of the circular pen stands the jealousy pen, from which reluctant chicks can view their comrades foraging treats. Gee and I laugh over this idea, which strikes home with me. I think of my four-year-old, who is much more willing to finish the food on her plate when she views her more cooperative sister getting ice cream across the table.
Finally, at 70 to 90 days which translates to midsummer the chicks are ready to fledge. But not until they travel to Necedah National Wildlife Refuge in Wisconsin for flight training.
The chicks arrived at Necedah on July 10. While adjusting to their new surroundings, they continued to follow the wingless trike. After a few days, the trike grew wings. In mid-August, all the chicks were able to fly. By August 28, the older birds, now nearly full-grown, were flying up to three and one-half minutes behind the ultralight.
There are numerous predictable disturbances along the flight path, most related to weather. The birds wont fly if its windy, foggy, rainy or snowy. There are also unpredictable upsets, as when the FAA grounded all flights following the September 11 terrorist attacks. Fortunately, on September 11 the cranes were being fitted with bands and radio transmitters. They were given a few days to get used to their new jewelry, so the FAA restrictions didnt affect their flight program. By early October, the cranes could fly more than 20 minutes at a time. They were ready to make the trip south.
We Have Liftoff
Two weeks ago, on October 17, at 7:15am, eight cranes sailed into clear skies over Necedah National Wildlife Refuge and into history, behind pilots Deke Clark and Joe Duff of Operation Migration. Shortly after take-off, one crane, known as number four, dropped out of the flight formation and proceeded to lead team members on a day-long search-and-rescue mission across two counties.
Entries from the Whooping Crane Eastern Partnerships website read like a good spy novel:
11:27amFrom opposite sides of Castle Rock Lake both [crane biologist Richard] Urbanek and [Barry] Hartup [from International Crane Foundation] picked up a weak signal that appeared to come from the area near where the crane was last seen. Following the signal, Urbanek headed down a dirt road to the lake shore hoping for a visual sighting
1:14pmUrbanek met up with Hartup/Zimorski at Castle Rock County Park and the two crews continued to scan the skies with binoculars and monitor the directional radio receiver
5:05amSprague and Zimorski put on crane costumes and with a hand-held radio receiver and a loudspeaker head into dense woods along the lake shore.
Finally number four is retrieved at 5:20pm and the wayward bird is given a second chance to join his flock on the migration.
Along the route, public and privately owned lands serve as stopovers. A staging area at Hiwassee Wildlife Refuge in Tennessee will provide a temporary layover if temperatures get too hot for the birds to continue to fly. Their destination is a saltwater marsh at Chassahowitzka National Wildlife Refuge in Florida. The entire journey, expected to take four to six weeks, would result in the longest human-led migration in history: 1,250 miles.
Dancing the Blues Away
photo courtesy of Operation Migration
Why such a big to-do over cranes?
Wild cranes need all the help they can get. Biologically, cranes dont have a lot going for them. Natural fertility in cranes is poor. Whooping cranes dont begin to produce fertile eggs until age five or six. Successful breeding depends on finding a compatible mate and breeding territory. Unmated females search for males with an established territory. Then the question is, ladies, can he dance?
It dont mean a thing if he aint got that swing. Bowing, leaping, running and flapping, stamping and tail fluttering: These crane dances are elaborate rituals that appear to be genetically determined. Even blind cranes in captivity know the moves. The object of the behavior, however, is learned. If a chick is raised by people, it will dance for people. Like love at first sight. When a female encounters a male who knows the right moves, the two may form a bond for life as long as they continue to be successful at breeding. If the cranes arent dancing together, they probably arent mating. A little charm can go a long way in the lives of cranes.
Whoopers breed in the far north where spring is short and re-nesting is seldom possible if a first attempt fails. Then there are concerns of egg viability and competition between chicks, which is fierce even when food is available. In addition, cranes build their nest on a low platform in shallow water, an easy target for predators.
Their food frogs, minnows, blue crabs, clams, sedges and berries, larval, nymphal and adult forms of insects, marine worms, acorns, and small invertebrates make them dependent on aquatic habitats throughout the year. Add to all their breeding pressures the disappearance of wetland habitat, and you have a nearly impossible species-survival situation.
In spite of all those pressures, cranes have lingered for over 40 million years. Fifteen species survive on five continents. No crane species have become extinct in recorded history.
Help from Friends
Gee does a delicate balancing act with his cranes, balancing genes. For, in order to preserve the cranes, scientists must preserve biodiversity. A population of about 500 cranes would be enough to ensure a healthy gene pool, which is the sum of all the genetic information carried by all the individuals of an interbreeding population.
Studies at Wood Buffalo focus on the productivity of crane pairs. Is a pair producing chicks on a regular basis? If not, why not? Losing a family line is one way to lose diversity. Increase is good. The wild population in Wood Buffalo is increasing at about four percent each year. At this rate, it will replace itself in five to 10 years. Gee considers this rate good enough.
Having some insurance is even better. In 1993, Gee began to establish a non-migratory population of whooping cranes on the Kissimmee Prairie in Florida. This colony numbers about 80 birds, including 15 pairs. Cranes from this population are released to the wild when they fledge.
We had a lot of difficulty getting started. The bobcat was a serious predator until we moved the birds to cattle ranches, which proved to be safer, Gee explains. We also had to help them change their nesting behavior [by teaching them to nest away from the edges of ponds.] This has made a big difference in their survival rate.
To restore crane populations, scientists need to understand the cranes hormonal rhythms and control disease, a constant concern at the captive crane colonies. At Patuxent, Gee studies ovulation and the egg-laying cycles of cranes, and he develops methods, including artificial insemination, to improve fertility. He also studies the effectiveness of vaccines, such as the Eastern Equine Encephalitis vaccine.
In the late 1800s, when about 1400 whooping cranes lived in North America, threats came from feather and egg collectors, hunting for meat and wetland loss. Contemporary environmental dangers are just as real but harder to pinpoint. Voice prints can help.
Voice prints record the tone, frequency and cadence of an individuals call, and, like fingerprints, are unique to each individual. Using voice prints, Gee can track birds on their migration from Wood Buffalo to Aransas and back, observing potential threats along the way.
Along the flyway, cranes encounter wetland loss, pollution, lack of food and fresh water and threats from high tension wires. Gee found lots of carnage of all kinds of birds in his study, the first of its kind, on the impact of high tension lines on migratory species. Simply placing orange aircraft balls on the high tension lines kept birds away. Fatalities dropped 90 percent.
If you and I care to be a good friend to cranes, then we need to do the same kinds of things we would do to save any wetland species. Conserve water and energy, reduce our dependence on household chemicals which end up downstream, recycle. Buy and eat local and in-season produce, while avoiding fish that are overharvested.
In the Field at Patuxent
After talking with Gee for over an hour in his office about his research with cranes, I asked, Can I see them? A smile came easily to his face. I like to visit them, too, he replied.
Driving to the pens, Gee points out other experimental sites. So much significant research goes on here. At an acid rain study site, he tells me, You know, sometimes the rain that falls here is like vinegar. At an old DDT study plot, Gee refers to the work of Rachel Carson who, as an employee of the Fish and Wildlife Service, introduced the public to the deadly effects of pesticides on birds and other wildlife. Can you imagine a meadow, he ponders, with nothing living in it but plants? We drive through woods, wetland, meadow and edge habitats and I notice lots of bluebird boxes, because we like bluebirds, Gee says, smiling again.
I hear the cranes before I see them. Theyre making an alarm call, he explains, because an airplane is flying overhead. The interruption disturbs them.
I dont wish to disturb them. Nonetheless, Gee opens the gate and we step inside one pen holding a crane pair. These cranes will not ever be wild, so they can see us in our human clothes and hear our human voices.
Gee makes a deep throaty noise. They know him and his noise and respond with their own crane noises and movements. Gee translates each call and posture for me. Youre lucky, he says as they come curiously closer. I feel lucky and privileged to witness these ancient wonders. Head bobbing, high-stepping on long black legs, their sleek white bodies approach until their red foreheads, black cheeks and golden eyes are level with mine. At five feet, they are the tallest birds in North America. I feel unease but unmistakable wonder.
One crane backs off a bit to a place where there is room enough for him to spread his immense, black-tipped wings. He struts his stuff with steps learned long before humans walked these woods and meadows.
And in this moment there is nothing wrong in the world. I am transported to a time and place beyond the confines of human boundaries. I feel like dancing, too.
Visit Patuxent National Wildlife Visitor Center two miles east of the Baltimore-Washington Parkway, off Powder Mill Road, just south of Laurel. Hours are 10am5:30pm daily. Interactive exhibits demonstrate the value of wildlife research. Visitors are not permitted to the cranes pens. Trails allow for exploration of a variety of habitats. All exhibits are free. Tour by guide tram weekends until November 11; $2 w/age discounts: 301-497-5760 www.pwrc.usgs.gov.
Track the cranes migration course on www.bringbackthecranes.org.