Primatology.net

In 1838 Charles Darwin jotted in a notebook, “He who understands baboon would do more towards metaphysics than Locke.” Baboon Metaphysics is Dorothy L. Cheney and Robert M. Seyfarth’s fascinating response to Darwin’s challenge.

Cheney and Seyfarth set up camp in Botswana’s Okavango Delta, where they could intimately observe baboons and their social world. But Baboon Metaphysics is concerned with much more than just baboons’ social organisation- Cheney and Seyfarth aim to fully comprehend the intelligence that underlies it. Using innovative field work, the authors learn that for baboons, just as for humans, family and friends hold the key to mitigating the ill effects of grief, stress, and anxiety.

This year marks the 60th anniversary of the founding of primatology in Japan, thanks to the works of Kinji Imanishi. Current Biology hosts an essay by Tetsuro Matsuzawa and William McGrew, which reviews Imanishi’s contributions to the field. The essay can be found at this link, “Kinji Imanishi and 60 years of Japanese primatology.”

I’m not too certain about Imanishi’s education. The piece indicates he was trained to be an entomologist. I deduce he specialized in ecology and animal behavior, because the review says he used to study Mongolian horses before he focused on primates. After his shift, Imanishi spent the rest of his life investigating the origins of human society by observing primates.

Anyways, the piece explains the various research projects after he started studying primates. This was three years after the end of the Second World War. Imanishi established several methodologies such as individual recognition, habituation and long-term observations, which are now standard techniques in the study of nonhuman primates.

Imanishi’s research also gave us insight to the mating habits of Japanese monkeys, their matrilineal societies, social hierarchies, and most importantly — the potato-washing behavior that is considered a proto-cultural behavior. You may have not known this, but this behavior, recorded by Satsue Mito, a student of Imanishi, in September 1953, is the first documented example of a cultural phenomena in nonhuman animals.

In February 1958, Imanishi traveled to Gombe, two years before Jane Goodall began her research. The photo below is from March 6th, 1958, where Imanishi (center) is pictured in Uganda, observing gorillas.

After his trip, he met up with Clarence Ray Carpenter, another primatology pioneer. Despite the death of Carpenter’s son against the Japanese during WWII, Imanishi was welcomed — a true testament of how science prevails. Imanishi gave the inaugural issue of Primates to Carpenter. Imanishi meet up with Louis Leakey and Sherwood Washburn, two big names in anthropology.

Imanishi was a true academic. He was inspired by other academics like Einstein, which motivated him to understand the world around him. If you want to know more about Imanishi, I recommend you check out this digital archive of his field notes.

Matsuzawa, T., McGrew, W.C. (2008). Kinji Imanishi and 60 years of Japanese primatology. Current Biology, 18, R587-R591.

I’m scouring the American Journal of Primatology for a paper on gorillas using tools as weapons in the wild. National Geographic News says the paper is out, but I can’t find it anywhere in the early edition nor in the current issues. I’ll continue looking, but in the mean time here’s what we got to run on (and it ain’t much)

“Researchers [doing a three year study of Cross River gorillas (Gorilla gorilla diehli)] in Cameroon have documented three cases in which the [gorillas] threw clumps of grass or tree branches at humans.”

The people who documented the behavior suggest that the gorillas possibly learned their unusual behavior from interactions with humans. Captive gorillas have been documented picking up stone throwing from their chimpanzee neighbors, so it’s not too improbably that wild gorillas could pick up grass and branch hurling from human neighbors. How did these gorillas learn the behavior? Could it be possibly due to mirror neurons? Conveniently this is a perfect transition into an upcoming PNAS paper on tool use and mirror neurons in macaques, that was announced in this ScienceNOW news article,

“To investigate how the brain performs this sleight of hand, [the team] recorded brain activity in two macaque monkeys. Each was trained for 6 to 8 months to grasp items of food with pliers. The team documented the activity of 113 neurons in F5 and in a brain area called F1, which has also been implicated in the manipulation of objects. The researchers first established the brain’s firing sequence when the monkeys grasped only with their hands. The experiment was then repeated while the monkeys used normal pliers that required first opening the hand and then closing it to grasp the food. The same neurons fired in the same order. Remarkably, the same neurons also fired, in the same order, when the monkeys used “reverse pliers” that required them to close their fingers first and then open them to take the food.”

The research is coming from the University of Parma which seems to be specializing in this sorta research because about a year and half ago they documented mirror neurons role in mimicry. In the new paper, the researchers,

“conclude that when learning to use a tool, the pattern of neuronal activity is somehow transferred from the hand to the tool, “as if the tool were the hand of the monkey and its tips were the monkey’s fingers.” As for how the same neurons could affect both the opening and the closing of the hand, the team speculates that they may be connected with other sets of neurons that more directly control these movements. The authors also point out that area F5 is rich in so-called mirror neurons, a type of nerve cell discovered earlier… that fires both when a primate performs an action and when it observes another individual doing the same thing. Mirror neurons in F5, the authors suggest, may be involved in this transfer process as a monkey learns how to use a tool by watching others.”

The first observations of gorillas using tools in the wild was made a couple years ago, and last year we saw (albeit not too convincingly) a chimp fashioning a spear to hunt, so I’m not too surprised about this news… I just wanna see it!

It seems that despite the wealth of information we know about primate behavior, especially chimpanzee behavior, we cannot fully grasp nor explain infanticide. In my opinion, primatology has not yet full investigated this unique and complicated behavior… well at least not until now. Before I get into the thick of new research on infanticide, let’s first define the term. Infanticide is defined as the killing of an infant and it is known to occur in many primate species. Most often in primates, and in other species, it is thought of as a male trait.

Take for example lions, when a male lion becomes head of a pride, he most often systematically kills all lion cubs. It sounds harsh. An unsupported evolutionary hypothesis for this behavior is that the male ‘wants’ to ensure his efforts as a leader influence the survival of his offspring and not the offspring of others… the whole selfish gene concept. The same could be said for male primates when they kill infants in their groups.

There is no explanation for when females engage in infanticide. Some justify female led infanticide as a pathological condition, where there’s something wrong with the female’s psychology. Surely it seems crazy, that the female, who invests so much time and energy and one of her eggs in rearing offspring, to kill one of her own. It gets a bit more complicated as far as jealousy/craziness when females begin to kill another’s infant. The pathological condition is what was hypothesized from Jane Goodall’s observations around the 70′s,

“Passion and Pom, a mother-daughter duo who cooperated in the killing and cannibalization of at least two infant offspring of other females.”

In a new Current Biology paper titled, “Female-led infanticide in wild chimpanzees,” authors Townsend et al., report three instances of female-led infanticidal attacks among the Sonso chimpanzee community in Budongo Forest in Uganda. From what they observed, they speculate these situations of female led infanticide are due to competition for limited resources. From ScienceDaily,

“Alerted to the killings by sounds of chimpanzee screams, the researchers directly observed one infanticide, and found strong circumstantial evidence for two others. Evidence suggested that in two of the cases, the killings were perpetrated by groups of resident females against “stranger” females from outside the resident group. Infants were taken from the mothers, who were injured in at least two of the attacks; in at least one case, adult males in the area exhibited displaying behavior, with one old male unsuccessfully attempting to separate the females.

The authors point out that these new observations indicate that such female-led infanticides are neither the result of isolated, pathological behaviors nor the by-product of male aggression, but instead appear to represent part of the female behavior repertoire in chimpanzees.

What drives the behavior is not yet clear, but may stem from demographic shifts that alter sex ratios and put increased pressure on females competing for foraging areas. In their report, the authors note that the Sonso community had experienced a significant population increase in the ten years prior to the infanticide observations (42 individuals in 1996 to 75 in 2006), and that there had been an influx of at least 13 females with dependent offspring since 2001. The population changes resulted in a highly skewed male:female sex ratio of 1:3, with relatively few males available to increase the home range.”

So there you have it, infanticide in this situation seems to be a numbers game — a means by which members of a chimpanzee community regulate population growth by taking into account the growth in the number of females in relation to growth in the number of males.

I doubt it is really as simple as that but it does provide us a bit more relevance to understand what is going on in the minds of these chimpanzees. We actually have a working model to base infanticide off of. I think we have proven time and time again how complicated chimpanzees are, they rival us in behavioral complexity. As hard as it is to derive why humans kill one another, it is equally challenging to pick that information out of a non-human species we observe in the wild. But this is a step into the right direction.

Personally, I have my own beef with sociobiology a.k.a. evolutionary psychology. I have yet to see it venture from a story telling, subjective science. But my issues don’t prevent me from acknowledging and respecting progressive work done in this subfield of behavioral studies and primatology.

I don’t know where Nick Wade truly stands about sociobiology, but I can tell he generally shares my sentiments on appreciating this issue, because he has eloquently summarized the work of Frans de Waal in his new article in the New York Times. I trust that you can tell what the topic and the scope of article is by reading the title, “Scientist Finds the Beginnings of Morality in Primate Behavior.”

At its core, this article is useful because it outlines the four basic behaviors for sociality, empathy, the ability to learn and follow social rules, reciprocity and peacemaking. If you think about it, our social structure is founded on it, and based off of years of Frans’ observations of chimps, macaques, and rhesus monkeys these traits exist to some degree in non-human primates.

Dr. de Waal makes the tangent that human morality has spawned off of primate sociality,

“but with two extra levels of sophistication. People enforce their society’s moral codes much more rigorously with rewards, punishments and reputation building. They also apply a degree of judgment and reason, for which there are no parallels in animals. “

The article goes on with a discussion on how Frans has stood up to criticism, competing and contrasting theories on the origins of human morality. I also noticed Nick opens talk about the origins and concept of religion, something I talked about here. But aside from the intricate subtopics, at the very minimum this article also provides us with some insight on why some of us study primate behavior…. even if it is story telling.

I’m curious to open this thread up to a discussion of how and where we think we developed our sense of morality? Is morality a behavioral trait inherited from our evolutionary relatives? Or is our morality a bi-product of our human only cultures? What do you think? Is there a grey area between these two? Can we ever truly find out where morality originated?