Take the O-Line

The orangutans at the National Zoo have a great opportunity to be independent agents—to move about freely, to choose their own location, to urinate on visitors’ heads: it’s called the O-Line.

To connect the great-ape house to the Think Tank, the area where scientists and orangutans collaborate on studying learning (although the orangs don’t get author credit), the zoo has built a network of towers connected by thick cables: these allow the orangutans to travel from the outdoor enclosure of the ape house to the Think Tank and back. The orangutans are also able to just hang out on one of the towers along the way—although a subtle but very present buffer-zone of electric fencing below the platforms prevents the apes from descending anywhere but within their enclosures.


It’s a terrific sight to see them brachiating along the cables with such poise and ease; it’s inspiring and also a little envy-inducing—you really wish you could do something like that yourself instead of engaging in this whole walking-upright nonsense. It reminds me of one of my favorite quotes from a college friend of mine: “You know what I miss most about evolution? Opposable toes!”



The cables stretch across the paths that visitors take through the zoo, and enough people have expressed alarm that a placard has been put up to answer the question: “But what if the orangutans fall?” (In case you’re wondering: they don’t. They kind of know how to do the swinging-from-vines thing.) The concern, it turns out, that more visitors should have is, “What if the orangutans pee on my head?” –And they do seem to derive a great deal of pleasure out of letting loose directly above the paths—so much so that volunteers are always asking people to stay out from under the cables while the orangutans are traveling on them. But the orangs also do other things, like hanging suspended from the wires, surveying the zoo—and swinging with the grace and weightlessness of trapeze artists.


I’ve already expressed my ambivalence about seeing, and watching, great apes in captivity, but the O-Line always makes me happy, just because it seems as if the orangutans themselves enjoy the experience. Maybe I’m anthropomorphizing, or maybe you just can’t help feeling, and expressing, some joie de vivre when you’re swinging through the air like that. Just imagine it—feeling the wind in your hair, looking down at awe-struck humans and contemplating your soon-to-be-empty bladder—how can that not bring about a warm glow of satisfaction?