Howler Monkeys

Howler monkeys have short snouts and wide-set, round nostrils. Their noses are very keen, and the Howler monkey can smell out its food (primarily fruit and nuts) up to 2km away. Their noses are usually roundish snout-type, and the nostrils have many sensory hairs growing from the interior. They range in size from 56 to 92 cm (22 to 36 in), excluding their tails, which can be equally as long, in fact in some cases the tail has been found to be almost 5 times the body length. This is a prime characteristic. Like many New World monkeys, they have prehensile tails. They can grasp items with it, hence why they are often found using their prehensile tails for picking fruit and nuts from trees. Unlike other New World monkeys, both male and female howler monkeys have trichromatic color vision. This has evolved independently from other New World monkeys due to gene duplication. They have lifespans of 15 to 20 years. Howler species are dimorphic and can also be dichromatic (i.e. Alouatta caraya). Males are, on average, 1.5 to 2.0 kg heavier than females. [Wikipedia.org]