So far, Tique, a 9-year-old female Pacific white-sided dolphin, doesn’t look any different, but her keepers at the Shedd Aquarium’s Oceanarium seem positively radiant these days.
Thursday night, they announced to Shedd members at the aquarium’s annual holiday party what has them so elated: Tique (pronounced TEE-kay) is pregnant. Hers is the first pregnancy ever in the 4-year-old, $43-million Oceanarium, built partially on the promise of becoming a major captive breeding facility for whales and dolphins.
Mixed in with the elation, however, is the bittersweet reality that the odds are against Tique’s first offspring surviving very long. As a rule, more than half of the first pregnancies of cetacean (whale and dolphin) mothers as young as Tique end up either as stillbirths, or with the calves dying before their first birthday.
“Because of this naturally high mortality rate and public disappointment,” said Ken Ramirez, assistant marine mammal curator, “a lot of institutions never announce a pregnancy when one occurs.
“We decided that this pregnancy represents such a rich learning experience for us, that we would share it with the public from the outset. We know we are risking a very big likelihood of a letdown with an unsuccessful pregnancy or an infant death.
“But all that is a part of the story of this animal’s normal life cycle, and this is a good way to get people to understand that story.”
There has been only one successful Pacific white-sided dolphin captive birth in North America, a female born in September 1993, at Sea World in San Antonio. Thus, marine mammal experts all over the world likely will be watching Tique’s pregnancy.
The Shedd is estimating that Tique’s calf, sired by a 9-year-old named Bulea (boo-LAY-ah), should be born sometime late next summer.
More Top Picks Best Field Watches For Men
Though Tique had never given any sign of being mature enough to be ovulating, Jeff Boehm, the Shedd’s director of veterinary services and research, began suspecting her pregnancy late in September. That is when a routine sample of blood, taken once a month from all animals in the Oceanarium, showed elevated levels of progesterone, a hormone associated with ovulation and pregnancy.
Over subsequent weeks, the progesterone levels remained high. Boehm began monitoring the dolphin with ultrasound equipment, which eventually confirmed the presence of a growing fetus.
Ultrasound images cannot measure the length of the calf, which is balled up in a fetal position in Tique’s womb, but Boehm estimates the fetus now measures about 1 1/2 inches in diameter.
Long admired as one of the fastest, most graceful ocean creatures, surprisingly little is known scientifically about this dolphin species. Experts, for instance, don’t know the dolphins’ gestation period, with estimates ranging from 10 to 12 months.
“This is just a great opportunity to learn a lot of things about these animals as we go along,” said Boehm.
“We see this as a chance to document some pretty basic things, like the growth rate of the calf, the weight gain of the mother and the length of pregnancy.”
Pacific white-sided dolphins are abundant in nature, ranging from Baja California north to Alaska and across the Bering Strait, extending down the eastern shore of Asia past Japan.
Only 22 of them currently are in captive collections in North America, counting the Shedd’s seven. Four of the 22 are males, including two males at the Shedd.
Tique came to the Oceanarium before it opened early in 1991. The Shedd collected her, two other females and Bulea, in late 1988 in California’s Monterey Bay area.
The original four have been the mainstay of the Oceanarium’s five daily public shows, astounding visitors with 25-foot leaps and other athletic displays. They, along with four beluga whales who share four giant Oceanarium pools, the biggest such indoor facility in the world, have been the nucleus of what the Shedd hopes will become important breeding groups for both species.
At this time last year, a second expedition off California to collect the Shedd’s other three dolphins was the object of a major animal rights protest campaign.
Activists, insisting that keeping intelligent, free-ranging ocean mammals in captivity is cruel and inhumane, threatened to launch an armada of small craft to harass the Shedd’s collection boats.
The armada never appeared, and the three new dolphins are also now in the Oceanarium’s pools.
Last October trainers allowed the three new dolphins, two females and a male, to begin swimming and interacting with two of the older females, Kri and Sira. Thus far, however, Ramirez has not let them swim with Tique and Bulea.
“We don’t know exactly how Bulea will act around the younger male,” he said. “And Tique has a sort of domineering spirit, so we decided to hold off on her introduction to the younger animals too.
“But we’ll introduce them soon. I would rather she gets used to the youngsters being around her now, before she has the calf.”
Given the slim survival chances of a first-born, Boehm and Ramirez have been more anxious than first-time human parents planning for the baby’s arrival.
“Ultimately, we decided we had to let Tique dictate the terms of her pregnancy,” Ramirez said. “She has continued to participate in the daily shows, and we want that, because she needs the exercise and mental stimulation.
“As time goes on, we probably won’t ask her to make the more strenuous leaps, but she may do it on her own, anyway, because it’s just part of a dolphin’s natural behavior.
“When the time comes closer to the birth, she’ll let us know which of the animals she wants to be around simply by the company she chooses. We’ll let her choose where she wants to be for the birth too.”
The original four dolphins have been sexually active for several years. Little is known, however, about their reproductive cycles. Boehm said it appears the females have bouts of ovulation a couple of times a year, which coincide with heightened sexual activity by the males.
“They engage in sex all year long, but it is on a very infrequent basis for long periods of time,” Ramirez said. “But a couple of times a year, for a period of two to three weeks, the male may seek out the females and copulate 10 or 20 times a day.”
Once pregnant, the female shows few outward signs of her condition, he said, until the last month, when her girth might become noticeably larger.
The birthing process itself is a crucial and breath-taking time, Ramirez said.
“The calf usually emerges tail first, its head last. They are about two feet long and weigh 20 to 25 pounds, and their skin is all creased up from being folded in the womb. It’s awkward at first, and you’re holding your breath, to see if it is going to rise to the surface to take its first breath of life.
“Right after birth, you wait to see if the mother will swim up to nuzzle and nudge the baby, and begin to bond with it. It’s really exciting.”
More Top Picks Best 50 Inch Tvs
Depending on where Tique chooses to be and the time of day the birth occurs, the birth of her calf could turn out to be a public event.
“It has happened at other institutions where the birth happened in the right place at the right time of day so that it was witnessed by hundreds of spectators. I suppose that could happen here too,” Ramirez said.
Several things can go fatally wrong in the first days, he said. Sometimes a new mother will not try to bond with the baby, for instance, or the baby, for whatever reason, won’t nurse.
Though there is little documentation on the lives of Pacific white-sided dolphins, there is a growing body of data on other cetaceans, particularly wild bottle-nosed dolphins. Those studies show more than half of all calves born to mothers younger than 15 die before reaching the age of 3. Nearly 20 percent die before their first birthday.
“There are only certain things we can control,” Ramirez said. “Our job is to make the conditions as comfortable and optimal as we can for the mother and baby, and hope for the best.
“We have to be realistic about history telling us that this first-born’s chances are not very optimistic. Even then, it would be a positive experience, a first step to the day when Tique has a successful birth and a baby that survives and thrives.”