PORTLAND, Ore. - It won't be long before we have a new addition to the elephant herd at the Oregon Zoo.
Rose-Tu is about to give birth to her second calf and we stopped by the zoo to check in on her and find out how she is doing in the final stages of her pregnancy.
The zoo's elephant curator, Bob Lee, told us they are monitoring Rose-Tu closely and she is doing well. She is expected to give birth any day now.
A hormone drop in Rose-Tu's blood will signify that she is going into labor. The zoo is doing daily blood draws so they can keep track of where the numbers are.
Even though Rose-Tu is about to give birth, it's difficult to tell just by looking at her that she is pregnant.
"Rose-Tu weighs just over 7,000 pounds right now and a calf is typically somewhere between 250 and 400 pounds," said Lee. "So she's not going to gain a tremendous amount of weight. And, in fact, we have to watch her weight very closely and make sure she is as fit as possible because that's the best way to ensure success of the calf."
There are, however, some signs that zoo visitors can look for.
"There are times when you can see some movements on her side," said Lee. "And especially as we start getting to the end here. You'll see the baby kick every once in a while. When folks come out to the zoo, they should really look at her side and study and look for those little movements. You can certainly see things."
Rose-Tu's diet hasn't changed much but Lee said they are trying to keep her moving because she tends to collect food and then stand in one spot for a length of time. So they have her on an exercise program to keep her strong and healthy.
The father, Tusko, will not have much interaction with the baby at first. The father enters the picture once the calf begins interacting with the herd.
"Samudra, when he was born, was supposed to be a girl according to that test," he said.
Samudra is Rose-Tu's first calf. You might remember that when Rose-Tu gave birth to him, she nearly trampled her baby. Zoo officials believe she was frightened and startled by giving birth since it was her first time and she had never experienced it before. They hope this time around Rose-Tu will not react that way because she knows what to expect.
"When Rose-Tu was pregnant the first time, she had never seen a birth and she had never been pregnant before," said Lee. "So she went through 33 hours of labor and then had this calf. And she didn't realize what was going on. So she became quite nervous and did what comes naturally for elephants when they are nervous - she stepped on him a few times."
Zoo officials separated the two and then put them through a re-introduction process. And it worked.
"Over the course of three days, we got her comfortable with the calf and we got the calf nursing," said Lee. "And once the calf latched on, you could physically see her relax. Hormones were released and she took over being a great mom. The third time we brought him over to nurse, she was actually nudging him back to nurse. She's been tremendous ever since."
"With this pregnancy, she has so much more information about what's going on," Lee added. "She'll understand what's going on. And that's one of the reasons we have the other elephants around. So they can experience it and see it so when they go through a pregnancy, they will realize what's going on as well."
Can Rose-Tu Have More Babies?
"Rose-Tu could have several more calfs," Lee told us. "Every four to five years she should be having another calf. And that's such an important time for the entire herd because these guys are designed to live together in a herd - to raise young collectively."
The zoo's senior veterinarian, Dr. Mitch Finnegan, is the on-call doctor for the labor and delivery. He was there when Rose-Tu was born 18 years ago and also when she gave birth to Samudra in 2008.
"That last birth easily took a year off my life," Dr. Finnegan said. "I hope this one goes easier."
"We're expecting the best and preparing for the worst," Dr. Finnegan added. "We'll have several carts of equipment and hopefully we'll use none of it."
One of the major complications that might arise is dystocia. This is where the labor stalls and veterinarians have to use medications to stimulate the uterus so the labor will continue. But even doing that could cause problems.
"Normally, elephants are delivered rear feet first," Dr. Finnegan said. "In very large animals like elephants, it's sometimes difficult to know whether the calf is positioned normally. Palpation and ultrasound are our best tools, but they provide relatively limited information in elephants compared to smaller animals like horses or dogs. The risk is that if drugs are used to stimulate labor and the baby is malpositioned, intense contractions could tear the uterus. Since we often don't have all the information we would like, it can be a harrowing experience if labor does not progress normally and medical intervention is necessary."
If the labor appears to be happening normally, Dr. Finnegan will keep out of Rose-Tu's sight.
"Ideally, we'll leave her alone and only have people in the barn that she's really comfortable with," he said. "As much as possible, we want it to be just another day for her. Animals are very good at sensing our emotions and stress, so we want everyone upbeat and mellow."
Infographic courtesy of the Oregon Zoo.