Four whooping crane chicks raised in captivity were brought into the wild over this weekend in continued efforts to bolster the endangered species' numbers.

The six-month-old cranes will reportedly be joining a flock of about 95 cranes that inhabit wetlands in the US Fish and Wildlife Service's Necedah National Wildlife Refuge (NWR) and other parts of central Wisconsin during the summer months.

And this release is just in time. Come autumn, the cranes will be gone from Wisconsin, winging their way towards wetlands in the Southeast United States.

The release also marks the first success for a new experimental program in which captive adult whooping cranes are used to raise hatched chicks.

"Over the past 13 years, USGS biologists - dressed in costumes to avoid having the birds 'imprint' on people - have raised between five and 20 whooping crane chicks annually that have been released into the Eastern Migratory Flock," John French, leader of the raise and release project, explained in a recent release. (Scroll to read on...)
[Credit: Hannah Hamilton , US Geological Survey]

Now, for the first time at the US Geological Survey's (USGS) Patuxent Wildlife Research Center in Laurel, Maryland, live cranes were used to raise the chicks instead.

"This new method ... is intended to evaluate the effects of rearing by humans in costume, which is obviously an odd condition," French added. "Parent rearing may result in the chicks learning behavior important to their survival and reproduction."

The chicks reportedly arrived at Necedah NWR on Saturday, where they will be housed in predator resistant cages until they become acclimated to the region. When the Eastern Migratory Flock makes its way near the center, the chicks will be released to rejoin the wild.

Not too long ago, it was believed there were fewer than 24 whooping cranes left in the word. Thanks to efforts like these, today's population is estimated to be more than 400, with an additional 125 in captivity.