Two small cheetah cubs have been born to a surrogate mother via in vitro fertilization (IVF) for the first time. Their births offer hope for the struggling cheetah population, and animal experts are calling it a "groundbreaking scientific breakthrough."
The male and female cubs were born on Feb. 19 at the Columbus Zoo and Aquarium in Ohio to surrogate mom, Isabel. Affectionately known as Izzy, the 3-year-old is a first-time mom.
The cubs' biological mother is 6-year-old Kibibi. The team harvested eggs from Kibibi and another female named Bella. They fertilized them with thawed semen from two different males and then implanted the embryos into Izzy and her sister, Ophelia. They chose to use the sisters as surrogates because they were younger and would have a better chance at healthy pregnancies. A cheetah's ability to reproduce drops significantly after 8 years old.
After three months, Izzy gave birth to the two tiny cubs. The father is 3-year-old Slash from Fossil Rim Wildlife Center in Glen Rose, Texas.
"These two cubs may be tiny but they represent a huge accomplishment, with expert biologists and zoologists working together to create this scientific marvel," said Dr. Randy Junge, the Columbus Zoo's Vice President of Animal Health, in a statement. "This achievement expands scientific knowledge of cheetah reproduction, and may become an important part of the species' population management in the future."
According to the zoo, Izzy has been taking great care of her cubs so far. Both cubs have been nursing and appear healthy.
A remarkable opportunity
Izzy is one of the Columbus Zoo's ambassador cheetahs. Many of them arrived at the zoo when their mothers were unable to take care of them, so they were raised by hand and are very accustomed to humans. Because of that, they have close bonds with their caretakers and have been trained to voluntarily allow X-rays, ultrasounds and other medical procedures. This training allows for minimal use of anesthesia and lets zoo staff to be near Izzy when necessary.
"In the 19 years that I've worked with cheetahs, one of the big challenges is that we have no idea if a female is pregnant until at least 60 days following a procedure or breeding. Working with the Columbus Zoo and Aquarium was a game-changer because their females are highly cooperative. We knew that Izzy was pregnant at five weeks by ultrasound and we continued to collect ultrasound data throughout her entire pregnancy. It was a remarkable opportunity and we learned so much," said Adrienne Crosier, cheetah biologist at the Smithsonian Conservation Biology Institute, one of the scientists who performed the embryo transfer.
Having the cheetah's cooperation is just one piece of the puzzle.
"This is a really big breakthrough for us with cheetah reproductive physiology but also with cheetah management"” said Crosier in a news release. "It gives us a tool in our toolbox that we didn't have before, where we can reproduce these individuals that are unable or unwilling to breed naturally."
Only the third try
Cheetahs are classified as vulnerable according to the International Union for Conservation of Nature (IUCN) and their numbers are decreasing, with only an estimated 6,674 left in the world. Threats include habitat loss, conflict with farmers and unregulated tourism, limiting them to just 10% of their range in their native Africa.
To help shore up those population figures, biologists at SCBI have tried artificial insemination in cheetahs for many years, but they haven't had a successful birth since 2003. They recently switched their focus to IVF on this project. IVF has been somewhat successful in small domestic cats and African wildcats, according to the zoo, but has been mostly been unsuccessful in large cats until now. This was only the third time scientist had attempted the procedure with cheetahs.
"The first thing we had to do is show that this technique works," said Junge. "Then we have to become proficient in it, so we can do it efficiently and reliably. With experience, we may be able to freeze embryos and transfer them to Africa."