A study at Rutgers University has revealed that there is an increasingly high number of violent human/chimpanzee interactions. The chimp often ambles away as the victor. This is not surprising as despite his diminutive stature, the chimp is thought to have an upper body strength of between 5 and 10 times that of a human being. The Rutgers study documents 11 chimp killings that have taken place since 1970, 8 of which have occured along the borders of the Kibale National Park in Tanzania.
Last night’s article in the Toronto Sun (April 21st) entitled “Killer Chimps” bought the issue to my attention. Apparently a group of chimps attacked four people at the Tacugama Chimpanzee Sancturary in Sierra Leone. Three of the four victims, tourists, escaped with serious injuries but the group’s driver was killed. Seventy apes live in the Parks borders and today paramilitary police are combing the surrounding jungle to see if they can capture any of the perpetrators.
Maggie and I had been discussing the primates of Costa Rica yesterday and she had mentioned that she knew of three types of monkey, the howler monkey and spider monkey who were quite passive and some other type of monkey who had on a number occasions demonstrated some unusually cruel behavior (“Hateful litle beasts” as Maggie called them.) The agressive primate species were known to have captured other small animals and tortured them, throwing the hapless victim amongst themselves, poking out its eyes and generally making sport of the killing. By their actions it is hard to not describe chimps in anthropomorphic terms.
What really intrigues me is why chimps choose to attack. They are a species that are so close to humans. I suspect that there are so many social and emotional connections that if we understood them properly, we would be horrified at not having given them the vote! I think that they might attack for many of the same reasons that humans attack each other. This manner of judgement would hardly seem all that inappropriate, to me they are so human-like that their actions would be quite obvious if we simply stopped seeing them as “animals” and instead considered them as “Distant cousins”. Like humans I think that at times the spirit of the moment might govern their actions. Controlled by a dominant individual or the frenzy of a mob, otherwise gentle beings might be induced into some rather uncharacteristic acts. There is also the aspect of territorial aggression and of course the age old motivation of testosterone.
Eight of the 11 attacks documented by the Rutgers study took place along the border of the Kibale National Park in Tanzania. A number of reasons have been suggested for this concentration, in particular the high population and the shrinking territory in which the chimps are confined as the local logging industry approaches the park’s borders. Its the age old problem of diminishing resources and increasing population. Somethings gotta give; we humans usually end up in a war.
An article by Wairagala Wakabi entitled “Drunk and Disorderly Chimps Attack Ugandan Children” comments on the prevalence of attacks in situations when the band is thought to have raided illegal brewing establishments. The moonshine industries are concentrated in river valleys along the Kibale Park’s borders where the chimps are also especially prevalent and once intoxicated they are known to become very agressive. There is onee notorious chimp known as “Sadam” who is reputed to have killed at least 3 babies. An untended child is usually snatched up by the drunken band and torn apart in the trees.
It appears that most chimps operate in a similar manner when attacking. It is not unusual for groups of chimps to attack the red columbus monkey, biting off its limbs and disembowelling it. Chimps are thought to only attack when they perceive that they have the advantage. They usually demonstrate by their facial expression,(A tight lipped grimace) what their intentions are. I suppose that their might be some variation in their method and by the manner of the attack one might surmise something of their motivation. In a great many attacks the victim’s feet are torn off. Genitals are another favorite target. I wonder if there is any corelation between the nature of the damage and the reason for the attack?
In an attack that took place in a California sancturary where an elderly gentleman had his foot torn off and genitals mutilated by two male chimps, Jeffery French, a physiobiologist from the University of Nebraska suggested that the presence of two other female chimps might have spoken of the motivation in some way. Apparently male agression in chimps increases in the presence of sexually receptive females.
The California situation arose when a couple visited the sancturary with a birthday cake for 39 year old Moe, a former pet and current inmate of the facility. They were just about to cut the cake when the lady present was pushed aside, having her thumb bitten off and the two male chimps that had been skulking on the sidelines then asulted the older gentleman. Moe stood by uninvolved in the incident. A theory proposed by Deborah Fouts, a chimp behavior specialist is that there was some jelousy. She says that primates have a highly developed sense of what is fair and what is not fair. It may have been that they resented the attention being lavished on Moe. The attack finally stopped when the agressors were shot by the owner.
The chimp’s tendancy to display individual agression is not surprising as it exists in most animal species but their tendancies to wage war seem very unusual. It is eerily human. One observer commented that though they wage war, they only pursue it as long as the odds are very much stacked in their favour. We humans dont always follow that logical path, a fact attributed to the increasing tendancy for the “war makers” to not nessisarily be the “war fighters”. The article “Wired For War”, a special to World Science” cites a case in 1998 in Uganda where a number of male chimps were seen beating and jumping on the body of another dead chimp. They had torn out his wind pipe and fingernails as well as pulling off his testicles. There are also examples of where “chimp genocide” has occured, whole population wiping out other populations.
Up until last night I had always considered chimps to be docile, hairy caricutures of a dim human but this mornings investigations have proved otherwise. There complexity seems astounding and their reactions quite complex. Next time you see some dopey looking little fellow staggering along in a pair of diapers, realize that there is a complex and developed brain behind those eyes, as capable of loving and trusting as it is of sheer, calculated ferocity and malice.