COLUMBIA, SC (WIS) - Over the last year, Riverbanks Zoo has had baby fever, but there is one species zoo officials would love to see have offspring that has not had any success.
For the last three years, two of Riverbanks' three tigers, male Vitale and female Koshka, have continued to breed, but Koshka has not gotten pregnant.
“We had become concerned,” Riverbanks Zoo’s Director of Animal Health Martha Weber said. “Is it that they’re just not a good pair, or is there something that is preventing them from reproducing successfully?”
Weber says the only way to know for sure was to call their partners at the Southeast Zoo Alliance for Reproduction and Conservation, or SEZARC.
“We work with everything from stingrays and sharks to tigers and cheetahs and elephants and rhinos and everything in between,” SEZARC Director Linda Penfold said.
But their visit to Riverbanks was their first time performing a tiger ultrasound. They’ve used other observation methods to study tiger fertility in the past, but they add the ultrasound allows them a closer look.
“We were looking at the reproductive tract to make sure there were no obvious abnormalities or pathologies,” Penfold said.
“We also are taking a look at what we call the pituitary function and pituitary is part of the brain and we're looking to see how that's responding because that part of the brain is critical for ovulation to occur,” said Laura Metrione, a research associate for SEZARC.
Both could hold clues to why Koshka hasn’t been able to have cubs. Riverbanks officials say tiger cubs from Koshka and Vitale would be greatly beneficial when it comes to the conservation of this endangered species.
“They are both ranked very highly in the Species Survival Plan or SSP for their genetics,” Weber said. “It would be great if we could get offspring from them.”
While the planning, set-up, and preparation to get to this fertility exam and ultrasound moment took hours, within minutes of starting the ultrasound, researchers saw one of the things they hoped to find.
“Do you see these two lines here?” said Penfold as she pointed to the ultrasound monitor. “Those are the two uterine horn's coming from the uterus.”
“You could see nice clear tissue with no evidence of any kind of masses or any edema which would be swelling or fluid in the uterus, and everything looked clean and clear and ready to go,” Mitrione said.
While researchers will continue to examine Koshka’s blood work and her results, researchers said they didn’t see an early cause for concern. Male Vitale’s exam also showed he was healthy and should be able to reproduce.
“I'm really optimistic and the specialists were also optimistic when we talked with them,” Weber said. “There's no physical reason that we can find right now that they should not be able to produce. They got us a lot of helpful pointers for how we can move forward and make sure we’re taking the best opportunities to put them together.”
Keepers say one of those pointers is to allow the Tigers more time together when Koshka is willing to breed. Keep in mind, in the wild tigers are solitary animals, so the tigers at Riverbanks Zoo have kept apart unless they show signs they want to breed.
We also asked vets why they would perform a fertility exam on a tiger when they wouldn’t be able to do one on a tiger in the wild.
“We just want to make sure they’re healthy,” Weber said. "If there is something that’s causing them to be unable to reproduce that may be related to their overall systemic health, and we want to know that because we want the animals that are here to live the healthiest lives they can.”
A tiger’s gestational period is just about three months, so if the tiger pair is successfully able to breed sooner than later it wouldn’t be long before there are tiger cubs at Riverbanks.