Howler Monkeys of Costa Rica (and their lion-like roar)

Costa Rica [2] has four species of monkey. Almost every visitor who ventures beyond San Jose [3] and the highlands will chance upon at least one troupe during their visit. It's almost guaranteed. Monkeys are everywhere.

If you don't see them, you'll hear them. Especially the howler monkeys. And especially around dawn, when the males proclaim their turf with lion-like roars that will make you jump out of bed. In fact, the howler's vocal ability is said to be second only to that of elephant in terms of how far it can carry. It's certainly SOUNDS scary. The males roar again at dusk, and whenever they feel that their turf is being disturbed.

In fact, the howler–the largest of the four species–is a harmless herbivore that spends its time living communally and relatively peacefully, munching on leaves and fruits.

The male's astonishing Pavarotti-like abilities are due to an unusually large larynx and throat that inflates like a resonating balloon.