Primates
laelaps | February 27, 2008
Even though it has a blurry spot, this is one of my favorite photographs of the orangutans (Pongo pygmaeus) at the Philadelphia Zoo. The enclosure for the animals wasn't a very good proxy for their native habitat, but it's possible (even likely) that the orangutan will become extinct within my lifetime. As a professor of mine who studied them once told my class, if you want to see them in the wild, do not delay.
laelaps | January 30, 2008
The black-and-white ruffed lemur (Varecia variegata) is one of two species of ruffed lemur (Varecia sp.), although there may be as many as three subspecies of the black-and-white variety. Like many other lemur species, the black-and-white ruffed lemur is presently endangered, populations existing at relatively low densities throughout its range on the island of Madagascar.
laelaps | January 26, 2008I'm still trying to figure out how to best divide up my term paper from last semester about the evolution of hunting behavior in primates and hominids, but one thing that I learned was that a number of living primates will eat meat or catch prey if given the opportunity to do so. Chimpanzees have taken meat-eating to a more organized level than every other living primate except our own species (although behaviors associated with hunting may be used in raids on desirable plant food resources), but baboons frequently take animal prey, too. The narration is a little over-the-top (as is the slow-…
laelaps | January 26, 2008
The ring-tailed lemur (Lemur catta) is the most well-known (or at least most recognizable) of the living lemurs, probably because it is diurnal species and spends a lot of time on the ground. Just because this species is relatively easy to study does not mean it's any less interesting, though. One of the things that I learned while at the Duke Lemur Center is that olfactory signals are extremely important to this species, and the lemur in the photograph is scent marking the chain-link fence with glands on its wrists. This species also has scent glands on the shoulders and genitals, and males…
laelaps | January 24, 2008
By now regular readers of this blog know that I have a definite affinity for saber-toothed critters, a rather motley assemblage of unrelated animals which include a large number of extinct and extant animals. Many primate species, somewhat surprisingly, fall into this category. Some representatives like baboons have extremely impressive canines (complete with a specialized molar to sharpen their teeth on), but lemurs also have some formidable dentition. In many primate species enlargement of the canines is a sexually dimorphic trait, males having larger canines than females. Gibbons are an…
laelaps | January 22, 2008
In addition to the blue-eyed black lemur I mentioned yesterday, the golden-crowned sifaka (Propithecus tattersalli) was another lemur I got the chance to see at the Duke Lemur Center. Like many other lemurs, this species is under threat from the development of agriculture and habitat fragmentation, although this species faces a further threat. Gold has been discovered in golden-crowned lemur habitat, mining operations becoming a further threat to the species. Such activities have resulted in this species being critically endangered, and it was sad to think that the lemur I saw at the Duke…
laelaps | January 17, 2008I haven't had the chance to fully read it over yet, but there's a new paper in PLoS about chimpanzees sharing foods raided from local farmers, the behavior potentially showing some parallels with meat-sharing behaviors seen in other populations of chimpanzees. I'll soon write something a little more detailed, but I will say that I think the paper is a little out of order (materials and methods should come before the results and discussion/conclusion). Likewise, be sure to look at some of the criticisms and caveats introduced by other primate researchers in the comments section, especially…
laelaps | January 13, 2008
A mother lowland gorilla (Gorilla gorilla) with her child, taken at the Bronx Zoo.
laelaps | January 9, 2008
While the mountain gorillas (Gorilla beringei)studied by Diane Fossey might be the most familiar to the public, the vast majority of living gorillas are Western (or lowland) gorillas, Gorilla gorilla. While myths about these animals had circulated for some time, they were officially named in 1847 (the mountain species not being named until 1903), but of the two gorilla species they are generally less studied. Western gorillas differ from mountain gorillas in that they eat much more fruit and are more arboreal, and some populations have been observed to use tools (the elusive Cross River…
laelaps | January 8, 2008
In the year I was born the Dutch primatologist Frans de Waal delivered a highly popular and influential book about the chimpanzees of Arnhem Zoo, the Netherland facility housing the largest captive population of the apes in the world. At first such a book might not have seemed so exciting, the well-known studies of Jane Goodall or Diane Fossey among apes in Africa making a group of chimpanzees in a zoo seem bland by comparison, but de Waal took advantage of the opportunities for detailed observation the captive setting provided and painted a vivid picture of the complex social life of…
laelaps | December 19, 2007
Barbary Macaques (an adult male and an infant). Via Wikipedia.
Part of the experience of living in an apartment involves occasionally being subjected to the sounds of members of our own species mating. While the torrid love affairs of our neighbors might keep us up at night, though, there's a good reason why they do it (just as there's a good reason why there's a whole business based upon the proclivity of some men to drop loads of cash to listen to a woman pretend to have orgasms over the phone), at least if we're anything like Barbary Macaques (Macaca sylvanus). In a new study published…
laelaps | December 19, 2007
The Pygmy Marmoset (Callithrix (Cebuella) pygmaea) is an interesting little primate. While it is often said on documentaries or zoo enclosure descriptions that they are among the most "primitive" of primates, marmosets actually have a number of derived features. On their hands, for instance, they have claws called tegulae instead of flattened nails. At first this would seem to be a characteristic that was retained from their ancestors, but tegulae are actually modified nails, meaning that the marmosets evolved claws in something of an evolutionary reversal. Likewise, marmosets often give…
laelaps | December 14, 2007
If you see an Orangutan (Pongo pygmaeus) at a zoo, they'll probably be carrying around a large piece of cardboard or a blanket like the one from the Philadelphia Zoo pictured above. The reason for this seems to be that orangs normally live in a forested, enclosed habitat and prefer to have something over their heads, and if there are no trees they'll work with what they have. Chimpanzees, too, like to have cover over their heads in the wild and largely fear open spaces like savannas, the population at Mt. Assirik in Senegal being an exception as they move in large mixed-sex groups over the…
laelaps | December 6, 2007I'm going to be out most of the day as I'm going to attend a lecture in New York on how useful (or not) living primates are in reconstructing the lifeways of extinct hominins (with a new copy of Peter Bowler's Monkey Trials and Gorillas Sermons to keep me occupied during the trip), but if you're looking for something good to listen to check out an interview on NPR with Dorothy Cheney and Robert Seyfarth about their new book Baboon Metaphysics. Included in the discussion is a mention of the creationism/evolution culture war and a story (originally related to me by my primatology professor, a…
laelaps | November 25, 2007
Yet another skull from the AMNH Hall of Primates, this time of a gorilla. This skull is quite different from those of the other apes I've put up recently, especially in the presence of a prominent sagittal crest for the attachment of jaw muscles.
laelaps | November 24, 2007
Like many of the other photographs I've posted over the last week, this one also comes from the Primate Hall of the AMNH, this skeleton belonging to a gibbon (Family Hylobatidae). Gibbons are often called the "lesser apes" (they are not included in the Family Hominidae, which includes orangutans, gorillas, chimpanzees, bonobos, humans, and extinct relatives), but they are among the most charming of all primates, at least in my opinion. What you might notice in the skull, however, is the size of the canines, a feature that might be unexpected in a monogamous animal. Enlarged canines are…
laelaps | November 23, 2007As Sideshow Bob once opined, television is essentially a "bottomless chum bucket," and even when I am petsitting at a house with cable I usually prefer to read over endlessly channel surfing for a nature program that I probably won't like anyway. Some programs on PBS, however, are notable exceptions, and I recently came across some YouTube videos of a Nature documentary all about baboons that I wish I had caught when it aired. I didn't always like baboons, but between reading the excellent book A Primate's Memoir (if you haven't read it already, I urge you to do so) and taking a course with…
laelaps | November 23, 2007When I look in the mirror to shave every few mornings or so, I know I'm looking at a reflection of myself and not another human who happens to be doing just the same thing that I'm doing at the same time. Even though I can be a bit shy in person to person contact, I am not afraid of eye contact, nor was I when I was a child, which allowed me to make the connection that the image I saw in a mirror was really me many years ago. Chimpanzees, bonobos, and oranguatans can recognize themselves in a mirror as well (gibbons and capuchin monkeys can't, even though they can use mirrors in different…
laelaps | November 21, 2007
As a follow-up to yesterday's photo of a juvenile Chimpanzee (Pan troglodytes), here's a photo of the adult. The differences between the adult and juvenile are quite striking; the adult skull has a more pronounced brow ridge, smaller incisors compared to the rest of the skull, more prominent canines, and is a bit more prognathus (the jaw sticks out more). Indeed, the infants and juveniles of these apes are not just small clones of the adults but change in important ways as they grow and mature, although as I noted in the comments yesterday juvenile chimpanzees seem to be strikingly familiar…
laelaps | November 18, 2007
Update will be a bit sparse today; I'm headed off to the AMNH in New York City with the undergraduate anthropology club, but hopefully I'll get some photos up later this evening when I arrive home. Among my favorite 4th floor fossils I'll also be headed back to the human evolution exhibit where the above fossil, the skull of Proconsul is displayed. Initially discovered in 1909, there are now as many as four species of this Miocene primate, although debate still goes on as to whether it is actually an ape (putting it closer to the line that led to hominids) or closer to Old World Monkeys (…