Rose-Tu's pregnancy enters the home stretch

June 22, 2012 - 10:15am

Rose-Tu, mother of Samudra, is expected to give birth in the fall

Let the countdown begin. Asian elephant Rose-Tu has reached the last stage of her pregnancy, according to Oregon Zoo animal-care staff, leaving behind what in human terms would be considered the "golden" second trimester and marching trunk-first into the home stretch.

This week marks Rose-Tu's 16th month of pregnancy. The 17-year-old pachyderm, who gave birth to Samudra in 2008, has been "in a family way" since February 2011, but her second calf isn't ready to be born just yet. The gestation period for Asian elephants is around 20 to 22 months.

"Rose-Tu has been through this before, and she's doing great," said zoo veterinarian Mitch Finnegan. "Right now, all we can do is make sure she maintains a healthy weight and gets plenty of exercise."

And continue to wait, of course. We should expect to see another member of the zoo's celebrated elephant family sometime between late October and the end of the year.

"Elephants live in matriarchal herds," said Bob Lee, the zoo's elephant curator, "and the arrival of a new calf is an incredibly important event for them. If everything goes the way we hope it will, the entire herd will bond around this new baby and help care for him or her, just as they have with Samudra."

Keepers believe the new calf was conceived around Feb. 22, 2011, when they observed breeding activity between Rose-Tu and Tusko, the 13,000-pound, 40-year-old bull elephant who fathered Samudra.

But even after 16 months, you'll need to look closely to spot Rose-Tu's "baby bump," Finnegan says. The bulge that zoo visitors have been noticing is actually the result of Rose-Tu's abdominal organs shifting to make room for the baby.

"For many wild animals," Finnegan notes, "the signs of pregnancy are a lot less obvious than they are in humans."

And while the zoo's elephant experts expect everything to go well, they also know the birth of a healthy baby is no sure thing.

"There are definitely risks involved," Finnegan said. "Complications can arise for both mother and calf. A calf may be stillborn or get lodged in the birth canal."

Another possible complication is how Rose-Tu might react to a new calf. After giving birth to Samudra in 2008, the first-time mom nearly trampled her baby. Keepers quickly intervened to save the young elephant's life, and zoo staff worked around the clock for a week to ensure the mother-calf bond became the strong one it is today.

Lee, who was senior keeper at the time, believes Rose-Tu became confused by the birth, since she had never before witnessed one. Until Samudra's arrival, no elephant had been born at the zoo since Rose-Tu herself in 1994. Lee and the rest of the zoo's animal-care staff are hopeful that, as an experienced mom, Rose-Tu will know how to react when her second calf is born.

The Oregon Zoo is recognized worldwide for its successful breeding program for Asian elephants, which has now spanned five decades. More than 25 elephants have been born at the zoo, beginning with Packy in 1962. Rose-Tu's mother, Me-Tu, was the second elephant born at the zoo (just months after Packy), and her grandmother, Rosy, was the first elephant ever to live in Oregon.

Asian elephants are considered highly endangered in their range countries, threatened by habitat loss and conflict with humans. It is estimated that only around 38,000 to 51,000 remain in fragmented populations.

The Association of Zoos and Aquariums' species survival plan for Asian elephants recommended that Rose-Tu be bred with Tusko. The AZA, of which the Oregon Zoo is an accredited member, strives to maintain a sustainable population of elephants in North America. Currently, birth rates are lower than necessary to do so. With few bulls and low birth rates — combined with an aging female population — the North American elephant population is at of risk becoming extinct.