So here's my theory. In The Graduate, there is a scene in which Benjamin is stalking Elaine, even following her onto a bus. He asks where she is going; she says to meet someone. He asks where. She says, "At the zoo." Incredulous at her having a date at a place usually associated with families with kids, he asks, somewhat condescendingly, "At the zoo?" "At the zoo," Elaine replies, as if this were totally normal.
And here we have a song called "At the Zoo," on the same album as "Mrs. Robinson," with the line "you can take a crosstown bus." So my theory is that the song was written for, but not used in, the movie.
Most songs about zoos-- from Tom Paxton's "Going to the Zoo" to Peter Himmelman's "Picnic at the Zoo"-- are, in fact, children's songs. Only a few songs that mention, or are set at, zoos, are for adults: "Zombie Zoo" (Tom Petty), "Knockin' 'Round the Zoo (James Taylor), "Gorilla You're a Desperado" (Warren Zevon). And these use the zoo, or the image of one, merely as a jumping-off point.
This one, however, is entirely for adults: The changes in tempo and tone, the match-striking sound, and especially the vocabulary. Aside from terms like "reactionary" and "turn on," we have the assertion that elephants are "dumb." A children's song would never make fun of, or demean, an animal. (We don't talk like that in this house, mister... say you're sorry.) Also, we have the bored zookeeper taking a nip on his frequent breaks.
We certainly have never heard of these animals being characterized these ways before. What is "honest" about a monkey, or "insincere" about a giraffe? If anything, monkeys are one of the few animals intelligent enough to make things up, while giraffes are barely audible and seem rather straightforward.
Most likely, this is simply Simon having fun in the same way as on the bus trip with Kathy in "America." The benign-looking man with the bow tie was just too benign; he was probably a spy. So, too, the placid-seeming antelopes are really interesting in selling you their religion, and the pigeons are not congregating to eat fallen popcorn but conspiring to rebel. Every once in a while, they let the secret slip; we think they say "coo," but they are really crying "coup!"
Simon clearly had fun with this song; and we can even hear him laugh during the recording. After the biting humor of "Blessed," "Pleasure Machine," "Desultory Philippic," and even "Mrs. Robinson," it's nice to hear the duo just enjoying playing with words and music. The mood starts light, as with "Cloudy" or "Feelin' Groovy," and the song ends with a jaunty, upbeat bounce of "Groovey Thing."
It's songs like this that remind us of the other side of S&G. While they are known for their sadder, more introspective and more challenging works, they never forgot that they were still-- in some part-- Tom and Jerry.
Simon has a charity, The Children's Health Fund, that involves sending trucks full of medical equipment-- basically clinic-mobiles-- out to poor parts of New York. They even drove their trucks down to New Orleans to help with Hurricane Katrina relief.
Jimmy Buffett turned his song "Jolly Mon" into a children's book, then Carly Simon followed with "Fisherman's Song." Paul Simon turned this song, "At the Zoo," into a children's book, too... with the proceeds going to The Children's Health Fund.
Although intended for adults, the song is Simon's most child-friendly (aside from the lullabies "St. Judy's Comet" and "Father and Daughter"). The line about hamsters "turning on" is finessed in the illustrations by having them wear miner's helmets with head lamps; the "zookeeper" is now fond not of rum but of a beaver named "Rum."
Next Song: Bridge Over Troubled Water