Several species of howlers are widely distributed through Central and South America. These are the largest New World monkeys and generally attain lengths of about 40–70 cm (16–28 inches), excluding the 50–75-cm (20–30-inch) tail. Howlers are stoutly built bearded monkeys with a hunched appearance and thickly furred prehensile tails that are naked on the underside of the tip to afford a better grip. The hair is long and thick and, depending on species, is typically black, brown, or red. Howlers live in groups within territories whose boundaries are mapped out by howling matches with neighbouring clans. Their voices carry for 3 to 5 km (2 to 3 miles) and can be heard at dusk, at dawn, and during rainstorms. Howlers are slow-moving monkeys that commonly sit on the topmost branches and rarely descend to the ground. They feed primarily on leaves. When on the move, howlers progress in orderly groups usually led by an old male.
Photographer: Dave Saunders