Whenever I get a reader comment that starts with, “I don’t want to be nitpicky. . . “, I know that what follows will totally pick a nit. Well, that’s usually okay in the interests of accuracy, and I have my own nit to pick this morning. (And do recall that “nitpicking’ has a biological origin: it originally referred to removing lice eggs—”nits”—from people’s hair.)
Today’s New York Times has a piece by Douglas Quenqua on attempts to breed the okapi in captivity. Okapis are artiodactyls (even-toed mammals) found in central Africa, and there’s only one species (Okapia johnstoni). Here’s a specimen (note the slightly elongated neck):
Okapis are in the mammal family Giraffidae, which contains one other species, the giraffe (Giraffa cameleopardis, of which there is only one species but many [contested] subspecies). The specific name of giraffes, cameleopardis, has a Medieval Latin origin reflecting the fact that giraffes have spots like leopards but faces like camels. See? (camel photo from Shutterstock).
Anyway, the gist of the Times piece is that okapis are skittish, solitary, endngered, and notoriously hard to breed in captivity:
The pairing of two okapis begins with the Association of Zoos and Aquariums, which keeps a “stud book” that contains genetic information on all okapis in American zoos. Mates are chosen to prevent inbreeding and maximize genetic diversity among calves.
Once they are paired, okapis at the Bronx Zoo are placed in adjoining cages with a multistage sliding door between them. At first, the door is opened just enough to let the animals smell each other. If they don’t respond aggressively, another part of the door is opened after a week or two so they can see each other, then another the next week so they can touch.
“They’re working it out socially,” said Pat Thomas, general curator and associate director of the Bronx Zoo. “We let them tell us when they’re comfortable.”
To prepare female okapis for pregnancy, they are given mock sonograms every day. The idea is to make the procedure, which requires close contact with handlers, less stressful for the animal and less dangerous for the humans.
When it comes time to give birth, the okapi mothers — unlike other animals in the zoo — are left alone, monitored only by a closed-circuit camera.
Breeding M’bura was somewhat simplified by the fact that her parents — Kweli, a 14-year-old female, and Poucet, “a genetically desirable male,” according to Mr. Breheny — had mated before. This time, the two were brought together in March 2010, and M’bura was born on June 2 this year.
But birth is not the end of the husbandry process. Because okapis are easily spooked, curators forgo neonatal exams on the calf. This reduces the likelihood that the mother will refuse to nurse or, worse, try to harm the calf. One way the handlers know the calf is doing well is if it doesn’t defecate for the first four to six weeks.
Live and learn. But what really bothered me about the piece (and I’m channeling Andy Rooney here) was this statement:
Okapis are the only known relative of the giraffe, but with the silhouette of an antelope.
What? “Only known relative of the giraffe?” In fact, everything is a known relative of the giraffe, including ferns, alligators, and humans! All species are related to greater or lesser degrees. The Times statement is like saying that “Jerry is the only known relative of his sister,” despite the existence of my many cousins.
What Quenqua meant, of course, is that okapis are the closest living relative of the giraffe, a statement that’s accurate.
What are the next closest relatives? Guess. It’s not obvious!
It’s the family Antilocapridae, which contains only a single species, the pronghorn antelope (Antilocapra americana) which is, of course, native to North America, not Africa. It’s the sole living representative of what was a diverse family of artiodactyls during the Pliocene and Miocene. Here’s a phylogeny from the reference given at the bottom:
Note that giraffes are more closely related to whales than to camels! That would surely confuse many laypeople.
Voilà le pronghorn, a lovely beast:
So that’s my nit, but one that bears on one of the most important findings of evolutionary biology: every species is related to every other. The Times should correct the sentence.
Price, S. A., O. R. P. Bininda-Emonds, and J. L.Gittleman. 2005. A complete phylogeny of the whales, dolphins and even-toed hoofed mammals (Cetartiodactyla). Biological Review: 80: 445-473.