The Best De-Fence

The saga of the bearded emperor tamarins at the Dallas Zoo may have had a happy ending, but the mysterious crimes that have plagued the zoo aren't necessarily over yet.  Overshadowed by these events has been the theft of a dozen squirrel monkeys from Zoosiana, the Acadiana Zoo in Louisiana.  The crimes do not appear to be connected, nor are these the first animal thefts at zoos (with primates being popular targets).  Still, it has led many zoos to decide that it's as good a time as any other to review security.

Historically, many US zoos were free public attractions that developed organically from city parks.  They consisted of a few cages or dens scattered about for anyone to come and see, and often they were not enclosed in any formal fence or boundary.  That, of course, left the animals exposed to threats at night - both animal, in the form of packs of stray dogs and other predators, as well as human vandals.  Losses at some facilities could be quite high, but there was widespread resistance in many cities against letting zoos put up fences.  With a fence, a zoo could control the flow of people coming in and out, and among other things, that would lead to the increased likelihood that the zoo might start charging admission.  Not surprisingly, many zoos saw those two factors - the gate and the gate fee - go hand in hand.

Even the increasingly small number of free zoos, however, are generally fenced in today.  It's just too risky and irresponsible not to be.  Not only does it keep intruders out, but it also serves as an additional form of confinement in the event of an animal escape.  For that later reason, it's considered best policy not to have any animal enclosures built into the perimeter fence, lest damage to one allows animals to escape from the zoo.  Ideally, the fence will be clean and accessible for the duration of its length, allowing staff to frequently inspect it and walk the perimeter.

Guards are another import security measure - usually human, though one zoo I worked at had a large and amazingly ineffective guard dog (I remember driving home late one night and seeing the dog a mile from the zoo it was ostensibly supposed to guard, playing in the middle of a street).  Guards should regularly patrol the grounds and watch for intruders; some facilities also employee designated night keepers to provide care for the animals after dark, such as neonates who might need a late night bottle, or pregnant animals on maternity watch.  A heavier night presence can be maintained in the event of emergencies - for example, if you're expecting a bad storm, some staff may stay late to monitor for falling trees which could damage fences.

Then, there are all the high tech gadgets - all of those cameras and sensors and monitors.  These are great devices that can allow staff to keep an eye on the facility and its animals, even from home.  Not only can they look out for intruders or fires, but they can monitor abiotic environmental factors, such as temperature for cold-sensitive animals or oxygen levels for aquatic systems and sound emergency alarms to notify staff in the case of equipment failure.

Of course, Dallas Zoo had all of these defenses in place - guards and fences and cameras - and they're still having problems with their mysterious enemy.  Which just goes to show that there's no defense system that is 100% effective against malice.