The Minds and Manners of Wild Animals: A Book of Personal Observations

The big and solemn long-nosed monkey of Borneo (Nasalis larvatus) utters in his native tree-top (overhanging water), a cry like the resonant "honk" of a saxophone. He says plainly, "Kee honk," and all that I could make of its meaning was that it is used as the equivalent of "All's well." Of all the monkeys that I have ever known, either wild or in captivity, the red howlers of the Orinoco, in Venezuela, have the most remarkable voices, and make the most remarkable use of them. The hyoid cartilage is expanded,--for Nature's own particular reasons,--into a wonderful sound-box, as big as an English walnut, which gives to the adult voice a depth of pitch and a booming resonance that is impossible to describe. The note produced is a prolonged bass roar, in alternately rising and falling cadence, and in reality comprising about three notes. It is the habit of troops of red howlers to indulge in nocturnal concerts, wherein four, five or six old males will pipe up and begin to howl in unison. The great volume of uncanny sound thus produced goes rolling through the still forest, far and wide; and to the white explorer who lies in his grass hammock in pitchy darkness, fighting off the mosquitoes and loneliness, and wondering from whence tomorrow's meals will come, the moral effect is gruesome and depressing. In captivity the youthful howler habitually growls and grumbles in a way that is highly amusing, and the absurd pitch of the deep bass voice issuing from so small an animal is cause for wonder.