Tuesday, February 10, 2009
Birds - The Whooping Crane
Whooping cranes are an endangered species although the population was never high due to over hunting in the 1800s. In the 1940s, the population decreased even more to less then 20. Due to the Whooping Crane's low population, bird care organizations do not allow them to go outside a protected area and they are now protected by law. Their habitat is very limited because they need clean wetlands, and there are only a few left. Notably, a small area of Wood Buffalo National Park in Northern Canada and in the Southern US states near the coast. Organizations are working to increase the crane population that today is about 377.
Whooping cranes have white feathers, long pointed bills and long necks. Cranes also have long thin black legs. However, they do not use their legs for swimming as when cranes are not standing in the water, they fly around their environment with the neck straight out in front and legs trailing behind. Cranes have noticeable black tips on the ends of each wing that you can see when they are flying with their young. Younger cranes do not have white feathers, although they are almost the same height as older cranes; they have brown feathers that gradually turn white when they grow older.
Whopping cranes eat snails, larval insects, leeches, frogs, minnows, small rodents and berries. When whooping cranes are in Texas, they will eat shellfish and small fish from the ocean.
Previous generations' migration routes help Whooping Cranes learn to migrate. Smaller cranes will follow their parents from the fall nesting grounds to the winter nesting grounds. Many cranes will have previously used the same migration route for thousands of years and continue to do so today. Researchers also help cranes to migrate by teaching them how to follow a truck on a set migration path they want them to follow so they can memorize it themselves. They also use cranes from the wild and set them free, then they recapture them and release them again. The researchers do this in the hopes that the cranes will connect the dots during migration.
These methods are effective, but the most successful method is the ultra light aircraft method, because it closely replicates the parents leading their children south during migration. Ultra lights are the only aircraft that can fly slowly enough (without stalling) so that the cranes can follow. Normally chicks are attracted to the first creature that nurtures them. To teach the chicks, prior to hatching, a recording of the aircraft is played to them, and then in 7 days the researchers introduce the chicks to ultra lights themselves.
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