Quin: GibbonsEucalypti, bathed in sun unsually warm for San Francisco, cast lacey shadows on the dusty footpaths wandering through the zoo. You might have thought it was Los Angeles it was so warm and dusty. Iron bars, two stories up, thirty feet by fifty, shaped a cage that cast harsh parallel shadow-bars over the dozen-or-so gibbons lounging there post-prandially. You might have thought they were sleeping but they were watching us. Quin and I had learned to play this game on earlier gibbon visits. Making ooo - wooop! shrieks like alarm signals on a ship pitching each set higher peaking, then oooo... descending, slow oooo..., oooo... Sex calls! Repeating the sequence drove the gibbons to a frenzy of requital. Swinging wildly round their cage returning ooo-woops and ooos they drew quite a crowd from the footpaths humans unaware of Quin and me and the game. At apogee wed knock off ventriloquizing and the gibbons would calm themselves. The humans seemed bewildered harumphed at one another then started off to see other jungle critters caged elsewhere. Giggle. Again? Ooo-wooop!