Howler Monkeys range in size from 56 to 92 cm, excluding their tail which can be equally as long. They typically live in groups of 10-15 animals having 1-3 adult males in the group.
Howler Monkeys are considered to be the loudest land animal as a result of an enlarged hyoid bone (lingual bone) a horseshoe-shaped bone in their neck. The main vocals consist of loud, deep guttural growls or 'howls' which can be heard throughout the day. As Guinness Book of World Records notes, their vocalizations can be heard clearly for 3 miles (4.8 km).
These Howlers were living in the trees in Playcar, Mexico - moving through the tree tops between the Sandos Resort to the Iberostar Tucan Quetsel Resort. They eat the leaves and the fruit. The resorts discourage human contact other that photographing and filming. However, there is one Resort Friend who has gained the trust of one of the males in this group.