Ferrets born at Zoo using 9-year-old frozen sperm

WASHINGTON - It took WTOP a while to "ferret" out the story, but the National Zoo has a new, unusual birth announcement.

Two black-footed ferrets were born in June at the National Zoo's Conservation and Research Center in Front Royal, Va.

But what makes the births unusual is that the ferrets' fathers have been dead for at least eight years.

The kits were sired by male ferrets who died in 1999 and 2000. The sperm was collected and frozen in 1997 and 1998.

"We wanted to use frozen semen as a way to input gene diversity into the population," National Zoo Reproductive Scientist Dr. JoGayle Howard says.

Successful inseminations with frozen semen are extremely rare, the zoo says. Until now, only three black-footed ferret kits were born from the method.

For more than 10 years, the semen was stored in the Zoo's Black-Footed Ferret Genome Resource Bank. The bank helps maintain and enhance genetic diversity by infusing new genes into the population and also serves as insurance against catastrophes in the wild populations, the zoo says.

Howard says the program is vital to keeping the species from going extinct.

The black-footed ferret is an endangered species that was thought extinct until of 18 were discovered in Wyoming in 1981. There are now about 700 in the wild.

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