Howler, Spider, and Woolly monkeys

The howler, spider, woolly, and woolly spider monkeys are New World monkeys found throughout the forested regions of Central and South America, from Mexico to northern Argentina. These monkeys have long prehensile tails with a sensitive, almost hairless, tactile pad on the underside of the distal part. They frequently use their tails as 'fifth limb' while moving through the trees where they make their homes. They also have nails on their fingers and toes, enabling them to climb. Most species have predominantly dark brown, grey, or black fur, often with paler markings. They are arboreal and diurnal animals that mainly eat fruit and leaves, however, the smaller species, in particular, may also eat some small insects. These monkeys typically live in social groups with up to 25 adults, depending on the species. Where groups are relatively small, as is common amongst the howler monkeys, a single male monopolizes a 'harem' of females, but larger groups will contain several males, with a clear hierarchy of dominance. Females give birth to a single infant (or, rarely, twins) and in most species, individuals give birth every 1 to 3 years. Vocal communication for howler monkeys, as their name suggests, forms an important part of their social behavior. They each have an enlarged basihyal or hyoid bone, which helps them make their loud vocalizations. Their main vocals consist of loud, deep, guttural growls or "howls". Howler monkeys are widely considered to be the loudest land animals. According to the Guinness Book of World Records, their vocalizations can be heard clearly for 3 mi (4.8 km)!