Save the whopping crane

The whopping crane's decline has been so drastic that its entire population numbers fewer than 200 birds. The fight to save it form extinction is slowly but successfully increasing its numbers.

Population decline

Fossilized remains of the whooping crane show that it was once far more widespread in the United States than in recent centuries.

During the 1 800s, its breed-ing range extended from cen-tral Illinois to the present-day Dakotas, and north into Canada. As this region was set-tled, the cranes left.

By 1950, the last known whooping cranes to exist in the wild were a colony of 15 that wintered in the Aransas National Wildfowl Refuge, established in Texas in 1937. The breeding grounds of these birds remained undiscov-ered until 1954, when a fire broke out in the Northwest Territories of Canada. Helicopter pilots helping to fight the fire noticed a pair of whooping cranes with their chick near a group of lakes.

Careful study revealed that these birds were from the Aransas National Wildfowl Refuge. They had chosen the most remote area possible in which to breed undisturbed.

Why the decline?

The crane is a shy bird that needs a large area of undis-turbed wetland in which to breed. Agricultural projects drained the water in many of these areas, which caused the crane to die out.

Much more destructive still was the extensive hunting of the whooping crane as it made its journey to and from its breeding grounds. Its large size and white coloration made it an especially easy target for hunters. Those birds that did escape after being shot often died after getting caught on power cables located in their flight paths.

Once a species has been reduced to very small numbers, it becomes increasingly vuInerable to natural disasters. Flooding of a breeding ground has been known to wipe out an entire colony of whooping cranes.

captive breeding program

The discovery of the breeding grounds of the remaining colony of whooping cranes allowed for the birds to be studied carefully.

It was known that, while cranes laid two eggs, only rarely did both chicks survive, Lisually because of competition between the two youngsters for food. By removing one egg from the clutch, there was a good chance that the egg could be reared artificially.

This procedure also benefited the single chick that was reared in the nest, as it eliminated competition for food.

Fosted parents

In 1975, a new method of artifi-cially rearing crane eggs was developed. A colony of closely related sandhill cranes in Grays Lake National Wildlife Refuge in Idaho was selected for an experiment in egg fostering. Whooping crane eggs were substituted for the sandhill cranes’ own eggs. The cranes incubated the eggs, which suc-cessfully hatched.

young whooping cranes were accepted by their foster parents as their own, and now whooping cranes are regularly raised in this way.

Migration routes

Whooping cranes begin their departure from their Texas wintering grounds in late March. The journey, which takes several weeks, follows a direct route from Texas to the Northwest Territories of Canada.

In mid-September, the birds follow the same path when they begin their winter migra-tion back to Texas.

The whopping crane's future

The decline in the wild popula-tion of whooping cranes has become a celebrated cause for conservationists, and, through their efforts, the wild popula-tion is increasing.

The population of whooping crane was at an all-time low in the 1930s, but it has shown a slow increase since then. From between 15 and 33 birds in the 1 930s, the numbers gradually rose to between 110 and 134 birds by 1987.

Barring natural disasters, the future of the whooping crane’s breeding and wintering areas seems secure, and the last remaining birds have a good chance of survival. Still, the population increase will be slow because of the crane’s poor breeding success, and the fact that many birds die before they even reach breeding age.

Only a continuing study of the species, a commitment to its protection, and public awareness will allow the whooping crane to flourish.

Other consercation measures

Although the desperate plight of the whooping crane was rec-ognized in the 1930s, its num-bers had already been severely depleted. Their population is now slowly recovering as a result of a captive breeding program and continued protec-tion of their Texas wintering grounds.

National campaigns have been launched to educate the public. Shooting of the birds, once a popular sport for hunters, has been banned. A special crane branch of the International Council for Bird Preservation was also formed.