It would seem difficult to overlook something as large as a new species of monkey, but scientists had no idea about the lesula until just a few years ago when conservation biologist John Hart discovered a specimen being kept as a pet in the Democratic Republic of Congo.
In retrospect, the monkey's striking, almost humanlike face should have made it hard to miss, and Hart, who spoke with All Things Considered host Melissa Block, is the first to admit that this new monkey was apparently not such a mystery to the Congolese themselves.
"As we talked to the local hunters ... we realized that this animal was well-known to the locals," he says.
That was in 2007. The monkey was being kept by the daughter of a school director in the town of Opala, in central Congo.
It had become "quite attached to her, quite attached to living in their little compound," he says. "It played with the dogs and the goats and the chickens and ate the same scraps from the kitchen that those other animals were eating."
After finding the specimen, Hart and his colleagues wanted to make sure it was really a new species before unveiling the primate to the wider scientific community.
"It was a young animal we started with and you can always be fooled by something young, so we wanted to see it grow up," he says.
Observations and genetic tests helped clinch the verdict: The lesula was indeed a new species, at least as far as science was concerned.
Hart's team then spent a few more years trying to piece together "its habits, its ecology, its range," he says. But that wasn't easy.
"They are shy, so when we started this study, we were getting relatively brief glimpses of them because they could detect us before we could detect them," he says.
Among other things, the scientists determined that lesula females average about 9-10 pounds, while males can reach as much as 16 pounds. Also, the animals spend a lot of time on the forest floor, which is unusual for a monkey, Hart says.
The discovery was published in the journal PLOS ONE. The journal says it's only the second time in 28 years that a new species of African monkey has been identified.
MELISSA BLOCK, HOST:
It looks like a monkey thinking very deep thoughts. With big close-set eyes, a long nose and thin mouth, its pink face framed by a long golden mane. It's a new species of monkey called the Lasula, identified recently in Africa in the Democratic Republic of Congo.
We reached conservation biologist John Hart in the Congolese capital, Kinshasa. And he told us how his field team first spotted the monkey back in 2007, on a trip to a forest in central Congo.
JOHN HART: They were at Opala, the last town on the way into the forest. And in the port, there were dugouts coming up from the forest and full of bush meat and plenty of dead animals. But there was this one live animal that they didn't know.
BLOCK: They brought photos back to John Hart, who's worked in Congo for 35 years, and he went to see the monkey for himself. He found one tethered to a post. It was being kept as a pet by the daughter of a local school director.
HART: I was familiar with all the field guides. I'd seen a lot of animals before and there was just something about this one, right away, that I knew was unusual.
BLOCK: And when you say you knew right away, what were you seeing? What did you see in this monkey that you hadn't seen before?
HART: Well, for me, was the red - bright red at the base of the back in the tail. I'd never seen that in a monkey before. And I thought is this some strange one-off case? It wasn't.
And as that young animal matured and as we saw older animals, we saw some of the other main features on them; these bright blue buttocks, their whole backside of the adult male is just this brilliant aquamarine; the yellow mane of hair around the head, all of those emerged as the animal got older. But that red on the back and the lower tail, that was just the one signal for me.
BLOCK: The images that I've seen of these monkeys, their face is just so sweet. Was there something about the expression on them that struck you right away?
HART: What there was, was we noticed right away the large eyes. And in fact, one of the analysis made by our morphologist was that this species has significantly larger eye orbits than any other related species, in almost any other monkey in this group of ceropithecus. So the fact that this animal spent so much of its time active in this crepuscular, pre-dawn darkness, and even at dusk sometimes we'd even hear the calls at night, made us wonder, is there still something to be discovered about this animal, as it's got a noctural behavior that would really be exceptional. It's all possible now, now that we know the animal.
BLOCK: John, I want to play some audio that your team recorded in the forest, in the Congo. And help us pick out where the monkey is in this recording.
(SOUNDBITE OF CONGO FOREST SOUNDS)
HART: Well, first of all, we're hearing all these night orthopterans, they're the grasshopper, cricket-like calling in the background and you hear the first birds making plenty of noise, as well. But in all of that, tucked in, almost, you know, if you don't listen it's gone before you know what you're hearing, you hear a low, little boom call and that was a lesula calling, not close, but it's definitely a lesula. They've got a very little, short little boom, and in fact if you hear it up close it does descend. It has a sort of (makes noise). But it's kind of a moaning call almost, a little. And that's them. And that's their time, right then when everything else is waking up and after that they're quite quiet.
BLOCK: It does seem surprising that with so much adventure travel, scientific expedition going on that there would be a species of monkey that nobody had documented before.
HART: That is remarkable. And this is only the second one in the last 28 years. And I never expected it. I don't think any zoologist ever really expects to find something new like this.
BLOCK: And John, we're talking about this monkey as a new species, but clearly it's not new to the Congolese. It's well-known there.
HART: That's right. That was, that became evident right, we didn't know what it was and our field assistants, who are also Congolese but not from that area, didn't know what it was. It's a well-known monkey within the restricted area of its range. And people didn't think there was anything particularly unusual about it. Of course, they didn't know that it wasn't, had never been added to the zoological literature. It was unknown zoologically, but for them it was known.
BLOCK: John Hart, thanks so much for talking with us.
HART: Thank you very much.
BLOCK: Conservation biologist John Hart, talking with us from Kinshasa in the Democratic Republic of Congo about the new species of monkey identified there, the lasula. There's a photograph of it at npr.org. Transcript provided by NPR, Copyright NPR.