In 2005, Mumbali, an adolescent female gorilla, was dying of a mysterious infection at Lincoln Park Zoo in Chicago. In a last-ditch effort to save her life, veterinarian and keepers anesthetized Mumbali and Kwan, a male gorilla, then laid them side by side to send Kwan's blood directly from his arm into hers. It was a crude procedure, similar to the way transfusions were done for humans before the blood bank was invented in 1937.
But there was little to go on in the veterinary literature, which had nothing about whether gorillas have different A-B-O blood groups like humans, or if they needed to have blood matched to their own for a successful transfusion.
"It's one of the most basic pieces of knowledge we need for the care of our animals, and it simply wasn't there," ape-keeper Jill Moyse said. Mumbali died despite their emergency interventions.
Five years later, Moyse and Kathryn Gamble, the zoo's chief veterinarian, have created an entirely new body of literature on great ape hematology. Just as important, they have produced an international registry to record the blood types of captive apes on four continents.
The registry represents all four great ape species -- gorillas, orangutans, chimpanzees and bonobos. In North America, it encompasses nearly every healthy male and female adult of the species who could donate blood if another ape of its species with the same blood type needed a transfusion.
"You don't want to transfuse the wrong type of blood, because a transfusion reaction can make a bad situation even worse," said Gamble, who published the project's research in the journal Zoo Biology.
"These are small populations," she said, "so emergency calls for blood are pretty rare. But when you need it, you really, desperately need it."
Before the project began, the only species of great apes with known blood groups were chimpanzees, the majority of which have Type A blood. That is known because chimps are frequently used as stand-ins for humans in medical research.
To learn more, the Lincoln Park project turned to a Danish company, Eldon Biologicals, which a few years ago revolutionized blood typing with small, chemically coated cards. A small smear of blood on the cards almost instantaneously reveals the donor's blood type.
Gamble and Moyse sent the cards out to North American and European zoos with ape collections and to African and Asian sanctuaries that rehabilitate injured and abandoned wild apes to restore them to the wilderness.
Because U.S. customs has strict controls about importing blood products, sanctuaries that lacked personnel to do the card analysis could not send the cards to Chicago, so Moyse sent them digital cameras to photograph the completed cards, e-mailing the photo for analysis at Lincoln Park.
Once the cards went out, it was several years before most eligible apes had their analyses done. Getting a blood sample from apes is no easy task. Though the test needs only a tiny blood smear, most big apes won't willingly undergo a jab of a sharp needle for a blood sample.
Because anesthesia is risky, keepers won't put animals down just for a blood sample. They do, however, anesthetize each of their adult apes roughly every two years for thorough physicals, so the project had to wait to get its blood.
The blood typing cards are revealing new information about the great apes. The project has verified that the blood of different ape species isn't interchangeable between species or humans, she said. It found that bonobos have only Type A blood, while orangutans have all four types, A, B, AB and O.
"Gorillas so far are somewhat confusing and frustrating," said Gamble. "Although all of their cards came back as Type O, it is clear from genetic evaluation from our collaborators at University of Chicago that gorillas don't in fact have all the same blood type."
Thomas Meehan, who heads the gorilla Species Survival Plan veterinary board for all North American zoo gorillas, said the ape blood type registry could do for apes what the blood bank did for humans. In particular it may result in new, lifesaving surgical procedures for apes.