Our Window on Nature

We began tracking whooping cranes in the late 70s, and wrote this article in 1983. But last week we found a wonderful video from National Geographic where you can see how these magnificent birds are “trained” to migrate following an ultra-lite aircraft.
There have been great success stories in the whooping crane recovery saga, with their numbers now approaching 500. Watch some terrific air photography as this group of cranes train for their two-month journey from Wisconsin to Florida. It’s taking place right now. (Link for the video at the end of the article.)

The best publicized bird on the endangered species list must be the whooping crane. We began following their story in 1979 with a visit to the whooper’s wintering grounds in Texas. With a wingspan of 6 1/2 to 7 1/2 feet, these huge white birds have come to symbolize the precarious position of much of the wildlife in our modern world.

Although the plight of the whooping crane is well known, few people are aware of the effort being invested in the foster parent program. Its purpose is to increase the chances for survival of North America’s tallest bird.

By the late 1940s fewer than 20 whooping cranes remained. Never very numerous, the population dwindled as their marshland habitat gave way to cities and farmlands. Since the whooper’s range extends beyond the borders of the United States, only by decisive international action could the whooper be saved.

First the governments of the United States and Canada established wildlife preservation programs at the birds’ sole breeding grounds in Wood Buffalo National Park in Canada, and at their wintering grounds in what is now Aransas National Wildlife Refuge in Texas. But so long as the birds were concentrated in such limited areas it was conceivable that the world’s entire population of whooping cranes might be erased by a Texas hurricane or an oil spill. And since all the birds followed the same migration route, they were vulnerable to careless hunters and unseasonable Spring and Autumn storms.

A rush was on to study the whoopers, so Canadian and American wildlife biologists “stole” a few eggs to incubate at the Patuxent Wildlife Research Center in Laurel, Maryland. Their captive-bred population offered a small margin of safety against disaster, but a caged flock runs a poor second to whoopers in the wild.

In 1975 the biologists, under the direction of Dr. Rod Drewien, began a program to have whooping cranes reared by foster parents. In the wild a female whooper lays two eggs each year, but usually only one chick survives. In fact, those whooping cranes with a single offspring are more likely to have a fledgling still alive to accompany them south than those who produce two chicks. By removing the “extra” egg, researchers hoped to bolster the existing flock while establishing a new whooping crane colony with totally different breeding and wintering grounds.

Fortunately, greater sandhill cranes are willing to accept the substitution of whooping crane eggs for their own. Each year biologists pack freshly-laid whooper eggs into special suitcases and rush them from northern Canada to Grays Lake National Wildlife Refuge in Idaho. There they introduce the eggs into sandhill crane nests and leave them in the care of their new foster parents.

When the program began the big question was, “Will the whoopers follow their sandhill parents south?” They did. Instead of wintering in Texas, the handful of foster-reared birds traveled to Bosque del Apache National Wildlife Refuge in New Mexico. We now have two small, but separate, flocks of wild whooping cranes instead of one.

Yet the problem won’t be solved until the foster-reared whoopers establish a true breeding flock. The oldest birds show an interest in choosing whooper (rather than sandhill) mates, but until actual pairbonding occurs, the success of the program remains in question. But the experiment is still young.

In the winter of 1982 the New Mexico flock had increased to 13. According to refuge biologist Mike Hawkes, last winter produced a gain to 15 New Mexico birds (although 17 were counted in Colorado during migration).

With only 15 birds in the New Mexico branch of the family, wildlife researchers take no chances with the birds’ welfare. They radiotrack the birds during migration and require that hunters at “the Bosque” pass special training courses to insure that no whoopers are shot by accident.

Last season the whooping crane total was 71 birds in Texas in addition to the 15 along the Rio Grande Valley. Although Bosque showed a slight increase, the Texas flock was down by the same number, meaning no overall increase for the year. With the cooperation of the sandhill cranes, this year may be better.

All of this puts new drama into fall migration in the West. A flock of cranes moves south along the Rockies announcing their passage with trumpeting that carries for miles. Wildlife biologists at Bosque del Apache wait and watch for a few more white birds with black wingtips among the birds of gray, bringing a brighter future for the whooping cranes.

Here’s the link to the National Geographic Video on the whoopers. Enjoy.