Many years of research are celebrated in the birth of two cheetah cubs at the Smithsonian Conservation Biology Institute—the first cheetahs (Acinonyx jubatus) born at the Smithsonian’s National Zoological Park facility in Front Royal, Va.
The cubs were born to two separate females; the first to 5-year-old Amani Dec. 6, the second to 9-year-old Zazi Dec. 16. Cheetahs that give birth to only one cub, called a singleton, cannot produce enough milk to keep the cub alive. Typically, females in the wild will let a single cub die, after which they will enter estrus and breed again to theoretically produce a larger litter. So scientists at SCBI resorted to an alternative technique. The cub born to Amani, a first-time mother, was hand-raised for 13 days before being placed with Zazi, creating a litter of two that will likely help stimulate milk production from Zazi. Researchers have observed both cubs nursing from Zazi.
“When we realized that Amani had a singleton, we removed the cub to hand rear it,” said Adrienne Crosier, SCBI cheetah biologist. “So when Zazi gave birth, we decided it was the perfect opportunity to give both cubs a chance at survival as one litter under her care without any additional interference by us. Only a few institutions in North American have ever successfully cross-fostered cheetah cubs and this is a first for SCBI.”
Amani’s cub showed abnormal cranial tremors when pulled for hand rearing. Initially veterinarians thought the tremors were associated with the cub’s hypothermia, but they became concerned when the tremors did not resolve despite the cubs’ seemingly normal growth and appetite. With the possibility of a lethal congenital brain disorder or developmental defect, the cub underwent some tests and advanced diagnostic imaging in the form of magnetic resonance imaging. The MRI results did not show a developmental brain disorder, and the severity and frequency of the tremors slowly improved. At that point, SCBI staff determined they could incorporate the cub into the foster family. They will continue to monitor the cub closely for any indications that his health could be compromised.
Both cubs were sired by 2-year-old brothers that arrived at SCBI in April 2010. The Association of Zoos and Aquariums’ Species Survival Plan, which pairs cheetahs across the country in order to maintain genetic diversity in the population, will likely consider the two genetically valuable, Crosier said. Eventually, they will be transferred to other breeding facilities.
These births are especially significant, as cheetah births in zoos across the country have dwindled over the past five years, worrying animal care managers about the sustainability of the North American population in human care.
Approximately 35 percent of female cheetahs in the SSP are older, and researchers have found that after 8 years of age they do not reproduce well. SCBI is trying to address the dearth of cheetah cubs through a number of research projects, including one project that looks at the reproductive potential of females as they age. SCBI scientists are also studying whether they can harvest eggs from an older female, fertilize them and then transfer them to a younger surrogate female.
“We are proud to help find a solution to maintaining a sustainable captive cheetah population,” said Steve Monfort, director of SCBI. “This is only our first year of having breeding pairs at SCBI, so it’s really exciting that we have produced two cubs. The more that we understand about our cheetahs, the more we can do for those in human care throughout North America and for those in the wild.”
Cheetah cubs in human care have about a 20 percent mortality rate (compared to up to 70 percent in the wild in east Africa), and animal care staff will continue to monitor the two cubs closely in the coming weeks and months. Thirty-three cheetah cubs (including the cubs born at SCBI this month) have been born in North America this year and have survived. With the new arrivals, the Zoo’s two facilities now care for 13 cheetahs.
Although SCBI is not open to the public, three cheetahs from SCBI were recently moved to the Zoo’s Washington facility, where visitors can see them in their outdoor habitat. Two litters of cheetahs have been born at the Zoo’s Washington facility since 2004, including one by Zazi, the cheetah now rearing the two cubs at SCBI.
Historically, about 95 percent of all cheetah cubs in the SSP have been produced in off-exhibit breeding centers. This includes five centers, including SCBI, that make up the Conservation Centers for Species Survival (C2S2), a group that collectively manages more than 25,000 acres of land devoted to the survival of threatened species with special needs (including those requiring large land areas, natural group sizes and minimal public disturbance). All five groups maintain a cheetah breeding facility as part of their long-term commitment to cheetah breeding and research. Collectively, these five centers manage more than 40 percent of the SSP population, and each C2S2 institution has produced cheetah litters this year.
As the result of human conflict, hunting and habitat loss, there are only an estimated 7,500 to 10,000 cheetahs left in the wild. The International Union for Conservation of Nature considers cheetahs a vulnerable species.
This work was made possible, in part, through the generous contributions of William P. McClure, William H. Donner Foundation, CGH Technologies, Ohrstrom Foundation, Nick Arundel and Magalen O. Bryant.