Mike McPhate
washingtonpost.com Staff Writer
Thursday, July 10, 2008 2:32 PM

Two rare horse foals have been born at the National Zoo's Conservation and Research Center in Front Royal, officials announced today.

The Przewalski's foals, a species native to China and Mongolia, were born four days apart on June 27 and July 1.

"It's really significant for us," said a zoo spokeswoman Pamela Baker-Masson. "We've tried for a very long time to get [the father] to breed."

The Przewalski's horse, the closest living wild relative of the domestic horse, went extinct in the wild during the 1970s. Through breeding of those held in captivity, their numbers have grown to about 1,500.

The two foals, a filly and a colt, were sired by a 9-year-old stallion named Frog. Biologists have ranked the father the most genetically valuable Przewalski's horse in the U.S. because his genes are so rare among the breed's population. The mothers were brought over from Europe to breed with Frog in late 2006.