It’s a girl.

The Oregon Zoo’s 18-year-old Asian elephant Rose-Tu gave birth early Friday morning to a 300-pound female calf.

The calf was born at 2:17 a.m. Zoo officials said the baby and mother were both doing well after 30 hours of labor and more than 21 months of pregnancy.

“We’re all delighted at the arrival of Rose-Tu’s new calf,” said Kim Smith, Oregon Zoo director. “The calf is beautiful, healthy, tall and very vigorous. As soon as she hit the ground — before she was even out of the amniotic sac — she was wiggling. And she’s vocalizing loudly. The first time we heard her, the sound was so deep and loud that we thought it was Shine. She’s definitely got a great set of pipes, and it looks like she’s going to be a real pistol.”

Zoo staff and much of the surrounding community had been on baby watch since Nov. 25, when Rose-Tu’s progesterone levels dropped to near zero, indicating labor should begin soon. Rose-Tu entered early labor in the afternoon of Nov. 28 and began showing signs of active labor around midnight last night.

Immediately following the birth, the zoo’s animal-care staff took the calf aside to clean it and perform a quick veterinary checkup, and they are working to reintroduce the mother and calf.

“Rose is doing considerably better this time around,” Smith said. “When Samudra was born, it was four days before she would even let him come near her, so we’re much farther along this time. We’re starting to see motherly behavior from Rose, and the calf is already nursing a bit. These are great signs that the mother-calf bond will be a strong one. Our animal-care staff is working hard to help the two along, and things are progressing every minute.”

Zoo visitors probably won’t be able to see the calf for some time as mother and daughter bond.

“The main thing determining that will be the strength of the bond between Rose-Tu and the calf,” said Bob Lee, the zoo’s elephant curator. “Rose should allow the calf to nurse regularly, sleep, play and generally act like a calf without trying to stop it and control its movements. Then we’ll determine whether she’s calm and comfortable with staff around. And finally, we want to make sure the calf has had a chance to bond with the rest of the herd.”

Zoo officials will select a short list of possible names and the zoo’s elephant fans will have a chance to vote online, the same way they helped name Samudra in 2008.

The Oregon Zoo is recognized worldwide for its successful breeding program for Asian elephants, which has now spanned five decades. Counting the new calf, 28 elephants have been born at the zoo, beginning with Packy in 1962. The zoo’s efforts have helped significantly expand understanding of elephant reproduction.

Rose-Tu became pregnant in late February 2011 by Tusko, the 40-year-old bull who also had sired Samudra. Throughout her pregnancy, keepers monitored Rose-Tu’s health and led her through exercises to facilitate a healthy birth.

The elephants at the zoo live in a matriarchal herd, as elephants do in the wild. Construction begins next year on Elephant Lands, an expansion of the elephant habitat that will quadruple the elephants’ space.