High Society at the Zoo

Primates – be they apes, monkeys, or lemurs – are easily among the most popular of zoo animals.  They also pose some of the greatest challenges to a zookeeper.  Part of it is that they are very intelligent and dexterous and agile, all of which lends to them being able to get into all sorts of trouble.  The aspect of their biology which has always caused me the most anxiety, however, is their social nature.

With few exceptions, primates are highly social beings.  Even some species which were previously thought to be very solitary, such as orangutans, are now suspected of being far more sociable than we thought before.  Even the less social species, when placed in a controlled environment with abundant food and resources, tend to loosen up and become friendlier.  For other species, such as mandrill, groups numbering in the hundreds have been reported in the wild.  When you hear things like that, seeing the dozens of macaques in Monkey Jungle’s crab-eating macaque colony makes a lot of sense, to the point where you start to wish more zoos would manage their monkeys on that scale.

About that…

“Social” does not, unfortunately, always equal “peaceable.”  Bigger troops lead to bigger conflicts, which is less of a problem in the wild where monkeys and apes can either get away from each other by leaving the group… or just die (which goes against the ethos of the zookeepers).  Managing primates in a zoo isn’t just about managing individuals – it’s about keeping on top of the whole soap opera drama of the group and knowing who is standing where in relation to who.  That is often established with fighting and chasing and other, subtler bullying.  When carrying for primates at one zoo, it seemed that every day the daily report was just a laundry list of who did what to who.   When I would come back from my days off, I felt like a kindergarten teacher who was getting a report from her exasperated substitute, who was full of gossip of how badly the kids had been misbehaving over the last few days.

There isn’t just drama within a group, there’s drama between groups.  Gibbons and howler monkeys spend lots of time yelling at each other (or at other groups) to establish territories.  It could be cool to have two exhibits of a species, located at either end of a zoo, able to hear but not see each other.  Each morning, the gibbons could hoot and holler at each other, confirming that everyone is going to stay in their own territory.  When the Bronx Zoo opened its massive Ethiopian Highlands, home to baboon-like geladas and other species, the thought was that it would originally house two troops of the large African primates.  For a while, it did, following careful introductions, keeping to separate territories.  Then, to the surprise of zoo staff, some geladas from Troop “A” and Troop “B” got together and formed Troop “C,” establishing their own territory.

 It can be challenging to do anything that benefits everyone equally.  Suppose you provide your chimpanzees with some awesome enrichment – the dominant animals may love it, and therefore monopolize it.  The bottom-ranking chimps, seeing something that they would love to play with but can’t use for fear of the big guys, may become very stressed.   Whatever resources you provide – food, toys, sleeping sites – you have to keep in mind that no one is going to be inclined to share evenly. 

It sometimes seems like the only thing worse than being in a social primate setting, is putting one alone.

I’ve met some primates, even of the most social species, who – as individuals – just hated everyone and liked to be alone.  That’s fair enough – some people hate everyone and want to be left alone.  Other times, however, when a primate is isolated for any reason – say, it’s sick and has to go to the zoo’s hospital – it can become very upset, sometimes even refusing to eat and getting sick.  In these cases, a buddy might be brought with them to keep them company.   And this isn’t even counting the drama that removing an individual from a group can cause, especially if it’s a dominant animal and leaves a power vacuum.

Some zoos have even begun to rethink the concept of quarantining new primates into their zoos, provided they are coming from a known source, such as another accredited zoo, with a known health history.  The thinking is that whatever possible health benefit might be gleaned from thirty days of observation is outweighed by the stress of isolation.  Better to just get that animal integrated into its social unit as quickly as possible.

I’m going to leave you with one more anecdote that I really think sums up the primate social network better than anything.  A zoo had a large troop of baboons, when one of them – the dominant male – died unexpectedly.   There was no heir apparent, and the rest of the troop began fighting and squabbling and generally being awful to each other.  Unable to stop the fighting, the zoo had a novel solution – they added a pair of chimps to the enclosure.  Immediately, the baboons stopped.  They were all united in their suspicion and fear of these mysterious, alien new beings and spent all day cautiously watching the chimps.  All inter-troop conflict was put on hold.  Eventually, they all seemed to forget what the fuss was about.  The chimps were removed (no one was harmed during this experiment), a new leader assumed dominance of the baboon troop, and everyone lived happily ever after…

Until the next petty squabble…