There has been a lot of discussion of chimpanzee aggression this past week. A baby
chimpanzee was killed in front of zoo visitors by a male chimpanzee at the LA Zoo
and a graduate student who had just begun working with chimpanzees was
horrifically attacked by two male chimpanzees at Chimp Eden in South
Africa. Journalists and much of
the general public are shocked.
Most people familiar with chimpanzees are responding to the shock by
explaining that chimpanzees are stronger than humans, that aggression is a part
of their natural behavioral repertoire, that chimpanzees are not domesticated and will
never be “tamed.”
I think there is more to it.
The aggressors are captive male chimpanzees who have not yet
mellowed with age (some older male chimpanzees can be remarkably caring and
sweet – but no one should let their guard down around them nonetheless. This is one
especially sweet old guy, Keo, who turned 54 this week. He is the oldest male chimpanzee in captivity).
 |
| Keo at the Lincoln Park Zoo (c) Steve Ross |
Captivity is stressful. Even the best captive conditions are stressful, and from
what I gather, both the LA Zoo and Chimp Eden are among the places that really
take chimpanzee well-being into account.
One very serious stressor for chimpanzees is being exposed
to new people, whether those people are unfamiliar humans or chimpanzees. At zoos, having new people constantly in one’s
environment is a significant stressor. The stress level
during introductions between chimpanzees is always high, and a new baby
inevitably causes shifts in group dynamics, which also adds to the
tension. Add zoo visitors
gawking and oohing and ahhing at the new baby and, well, the sad outcome at the LA Zoo could
have been predicted. But that it was predictable,
doesn’t mean it is the same as infanticide in the wild. No one really knows enough about
infanticide in the wild. Maybe one
cause is stress. To point to infanticide
in the wild as an explanation for what happened at the zoo, seems simplistic
and wrong-headed.
Captive
chimpanzees engage in very different behavior than wild chimpanzees. To take just one obvious example, no
one would walk among captive chimpanzees in the way that primatologists have
been doing at field sites throughout Africa for decades.
Perhaps that slippage contributed to the tragedy at Chimp
Eden, where the young graduate student was horribly mauled. This incident also involved a lot of
new people and territorial issues with captive chimpanzees. The student was new
to the facility, he was lecturing to visitors to the sanctuary, and he was
standing in an area (with his back to the chimpanzees?) where he should not
have been.
Yes, chimpanzees are aggressive. But captive chimpanzee aggression is different than wild
chimpanzee aggression. It would be
interesting to learn more about each.
Aggression is just one part of captive chimpanzee
behavior. Another big part of
their behavior is their compassion, courage, wisdom, and humor. And in some rare
circumstances it makes sense for those who know them very well to interact directly
with them. This is what Gloria
Grow did when beloved Pepper was dying.
I’m glad she was able to be with Pepper in this way. It was a tribute to the depth of their
relationship and Pepper’s profoundly “good” nature that Gloria was able to intimately
hold her as she left this world.
Please read her memorial tribute here. RIP Pepper.
 |
| Pepper (c) Frank Noelker |
Great post, Lori. I've been concerned about the quality of some of the chimpanzee research lately -- but you point out an intriguing area that is ripe for study! I hope someone picks up on your idea for looking at the differences between captive and wild chimpanzee aggression.
ReplyDeleteThanks Dawn. I think this sort of research could actually improve captive conditions and hopefully minimize stress and aggression in captivity!
DeleteHi Lori,
ReplyDeleteThe points you raise are interesting, though the issue at the L.A. zoo was less about the stresses that zoo chimpanzees must contend with (in general terms) and more about the known problems of breaking up a family unit (the social hierarchy is often fragile when outsiders get involved, especially during times like these when things become uncertain, and changes to an individual's status, rank, and role may swing wildly when seperated from the group) and the reintroduction that must follow. Many would not have split up the family unit to preserve the social structure, and few would have done so with the intent of reintroducing with an infant so small.
On the broader topic of stress in sanctuaries and zoos, the neurology, the neurophysiology, and the neurogenetics are much closer between human and chimpanzee than at the level of the genome to general anatomy and physiology. The Human and chimpanzee genomes are not 98.6% identical (though quite a few good biologists get this wrong) but instead we are that close at the level of the transcriptome (about 5% of the total genome for each) and no one has any idea how close our genomes are (maybe 80% - maybe 99.999%). However, how our extraordinarily similar gender-based development occurs is remarkable, and it is a central focus of my work.
When we raise great apes in environments that truly do not suit their evolutionary heritage, behaviors arise we would call aberrant or abnormal, when compared with those raised in native (natural) settings. Though some continue to say that individuals (esp. children) are "resilient", this wrong - we are all malleable (think of clay – you can add to it, mold it, and carve away any portion – but no matter how hard you work, it can never be “truly” remade into the original block of clay). Environmental forces shape genetic expression, starting as far back as our grandparents and possibly farther, and continue right up until our own death. The brain and it's gene-regulated development is susceptible to the epigenetics of both maternal and paternal endowment, fine-tuned while still within the womb, supported or impinged upon in the infant's environment, further ratified to a great degree until well beyond adolescence, and remains available to additional restructuring as the ape (human or non) ages into twilight. Unfortunately, the as our brains have grown large and complex, so too as the kind and degree of behavioral deviation possible; developmental, mood, and personality disorders are the price we pay for having the great brain plasticity that permits such fantastic learning, or terrible damage to both form and function, primarily during the most sensitive stages of growth.