A new baby elephant is on the way at the Oregon Zoo.

Zoo officials announced Monday that Rose-Tu, a 13-year-old Asian elephant is 10 months pregnant.

With a gestation period of 20 to 22 months,Rose-Tu will likely give birth in September or October 2008. Tusko, a 13,500-pound, 36-year-old Asian elephant, is the father.

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"We were confident that when we introduced Tusko to the girls, sparks would fly," said zoo Deputy Director Mike Keele, who also serves as the Asian elephant Species Survival Plan coordinator for the Association of Zoos and Aquariums. "From what we saw that day, Tusko was a true gentleman, a real 'lady's elephant' -- a true Casanova."

SLIDESHOW: Rose Tu expecting

Rose-Tu gets along very well with Tusko and seemed receptive to his advances. Her keepers described Rose-Tu as playful and highly intelligent and said they hope she will be a doting mother.

"The birth of a new baby is the most enriching thing that can happen in an elephant herd," said Keele. "If all goes well, and we hope it will, the herd will tightly bond and protect the baby as if it were their own. It's still early in the pregnancy and there are some risks associated with being a first-time mother, but we're hopeful."

There is a 40 percent infant mortality rate among captive Asian elephants.

Tusko arrived at the zoo in June 2005 on a breeding loan. He has successfully sired three calves in the past-two while living in Canada and one in California.

An endangered species, Asian elephants are represented by an estimated 38,000 to 51,000 individuals living in fragmented populations in the wild. Agriculture, deforestation and conflict with humans pose a constant threat to wild Asian elephants.