I would like to receive the following free email newsletters:

Newsletter Signup
  1. Bridal Party
  2. Dining Out
  3. Kliman Online
  4. Photo Ops
  5. Shop Around
  6. Where & When
  7. Well+Being
  8. Learn more
Where Do Zoo Babies Come From?
Scientists at the National Zoo are using high-tech ways to breed animals and save some from extinction. By Emily Leaman
Comments () | Published September 1, 2009

Ninety minutes outside Washington are National Zoo animals that few visitors ever get to see. Gone are the lines of tourists, gift shops, and ice-cream carts. In their place are wild animals that live and roam in the shadow of the Blue Ridge Mountains.

The National Zoo’s Conservation and Research Center is perched on the side of a mountain in Front Royal. From a grassy clearing, you can watch cars wind along Skyline Drive, the drivers unaware of the cheetahs, red pandas, and 400 other exotic animals nearby.

The center is nearly 20 times larger than the zoo’s DC location. There are a state-of-the-art veterinary hospital, half a dozen research labs, a satellite-imagery lab, and acre after acre of enclosures for animals.

Just inside the front gate is a pair of clouded leopards—cats with extra-long tails, large paws, and spotted coats. These animals made headlines twice this year when the female, Jao Chu, gave birth to a pair of cubs in March and another cub in July—the first clouded leopards born at the National Zoo in 16 years.

To the right are a dozen red pandas. These shy, sleepy animals, which look like foxes crossed with teddy bears, keep watch from perches in their silo-like enclosures. Keepers say the animals feel safest when they have room to climb.

Farther up the mountain, you pass the crane yard, which holds different endangered species of the oversize bird. In the rolling pastures beyond are Persian onagers, Przewalski’s horses, and antlered Eld’s deer.

The new cheetah facility is the last stop. Built in 2007, the nine-acre compound is a network of indoor/outdoor spaces with room for up to a dozen adults and their offspring. It includes living quarters, an exercise yard, and what one keeper calls “lovers’ lane,” a side yard for males to parade in front of interested females.

In many ways, the research center is like a real-life Jurassic Park. More than half of the animals are endangered. Scientists here study wildlife reproduction and develop techniques to make captive breeding easier and more successful. They chart hormone levels, tweak diets and habitats, and monitor animal behavior in large-scale settings that wouldn’t be possible at the DC zoo. Their goal is to save animals from extinction.

Many National Zoo scientists have been credited with making big strides toward that goal—artificially impregnating a giant panda, for example—and rightly so. But two decades ago, one unlikely scientist helped set the stage for almost everything they’ve been able to accomplish.


In 1973, Jon Ballou entered the University of Virginia to study political science. The son of a Foreign Service officer, he’d grown up in Asia. His father worked at embassies in Singapore, Japan, Hong Kong, and Beijing. Jon Ballou dreamed of working at the United Nations.

But late in high school, his father gave him a copy of Robert Ardrey’s The Hunting Hypothesis. The book, which draws parallels between animal and human behavior, fascinated Ballou. He signed up for an animal-behavior class at the University of Virginia and, as a sophomore, declared a major in animal-behavior science.

After graduating in 1977, Ballou read a story in the Washington Post about National Zoo volunteers who were conducting behavior studies. “I don’t recall thinking it would lead to anything,” says the 53-year-old with a salt-and-pepper beard. “It was something to do while I looked for jobs.”

The zoo already had started practicing conservation biology, a field that’s rife with controversy today. “The core struggle is between scientists who say we’ve lost the war against wildlife extinction and those who believe we haven’t,” says acting director Steve Monfort. “We’re the optimists.”

That’s the stance the zoo has taken since it hired its first scientist in the late 1960s. Most zoos then didn’t have a science mandate, much less the budget to support research. Even today, very few zoos have scientists on staff; the National Zoo has 35.

As a volunteer at the zoo, Ballou was put in charge of monitoring the Indian rhinos. After a few months, he was offered a $6,000 yearlong contract to do data analysis. He accepted.

Ballou didn’t know it then, but he had gotten his foot in the door at a time when zoos were on the brink of a major change.


In 1989, 33-year-old Ballou presented a paper at a conference at the Conservation Research Center. He stood in front of a roomful of colleagues and wrote four equations on an overhead projector.

For ten years, Ballou had been searching for the best way to manage the gene pools of animals in captivity. He had a theory that if you could identify animals with the most underrepresented genes and breed them with the right mates, you could maintain a healthy level of genetic diversity. Using family trees, he thought he could come up with a formula to identify the most genetically valuable animals. He had narrowed it down to four possible equations.

Ballou remembers his eureka moment. He was standing behind a lectern, explaining the equations one by one, when he felt a surge of adrenaline: “One of the formulas just made sense,” he says. “It clicked.”

His formula was dubbed “mean kinship”—a measure of the relatedness of captive animals. It yields a numerical value between 0 and 1 for each animal; the closer the number is to zero, the less related an animal is to others in a population of its species. Its genes are the rarest.

Ballou and two colleagues developed software to crunch the numbers. The program is called Population Management 2000. It yields lists of all the breeding animals in a population, ranking them according to their genetic value. Scientists can then make recommendations for breeding pairs that will best maintain or improve a population’s diversity. The software is now used for more than a hundred species at zoos around the world.


People & Politics
Subscribe to Washingtonian

Discuss this story

Feel free to leave a comment or ask a question. The Washingtonian reserves the right to remove or edit content once posted.
blog comments powered by Disqus

Posted at 12:00 AM/ET, 09/01/2009 RSS | Print | Permalink | Comments () | Articles