This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
There's one more white-naped crane (Grus vipio) in the world today, thanks to an innovative breeding program at the Smithsonian's National Zoo in Washington, D.C.
Fewer than 5,000 of these rare Chinese cranes are believed to exist in the wild, and the birds that are left aren't breeding very frequently. Making matters worse, very few female cranes have been born in captivity in recent years, putting the entire breeding program at risk as its gender balance gets out of whack.
The National Zoo's North American White-Naped Crane Species Survival Program received the chick's mother from China earlier this year, but the 20-year-old female was hand-raised by humans, had never given birth, and did not have experience with other birds of its species. According to the Associated Press, she "didn't know how to do the dancing, unison calling, stick tossing and other rituals that are part of crane courtship," and when the male she was matched with didn't see those expected movements, he ended up attacking the female.
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And so scientists at the National Zoo tried a different tactic: artificial insemination. It wasn't easy. "Bird keeper Chris Crowe slowly earned the female crane’s trust—playing with her, sitting with her, adapting her to his presence and touch—and was eventually able to successfully artificially inseminate her without using restraint or anesthesia," according to a National Zoo statement.
(We hope she got dinner first.)
The next step was equally important. The zoo wanted to make sure that the resulting egg was holding a female chick, without which their breeding program would face eventual stagnation. To accomplish this, Zoo staff developed a new technique that allowed them to penetrate the eggshell and extract blood without killing the embryo or introducing potentially deadly microorganisms. They were then able to determine that the chick was, indeed, a female.
The valued female chick was born on May 23rd, and is currently being raised by her paternal grandparents, since her mother has never learned any maternal skills.
Meanwhile, white-naped cranes in the wild face a dangerous next few years. They have already lost a great deal of habitat to human development in the Yangtze basin, and according to the IUCN Red List, their wetland homes are currently in the middle of a drought expected to last until 2015, which has already hurt their breeding success rates. That's why the National Zoo considers their breeding program to be so critical: some day soon, it might be needed to ensure the survival of the species.
Image: White-napped crane and chick, courtesy of the Smithsonian National Zoo