Mantled Howler Monkey
Alouatta palliata

f4 @ 1/1000s, ISO:800, Nikon D3S w 500mm

"Howler Monkey," Wikipedia, the free encyclopedia. As their name suggests, vocal communication forms an important part of their social behavior. They each have an enlarged basihyal or hyoid bone, which helps them make their loud vocalizations. Group males generally call at dawn and dusk, as well as interspersed times throughout the day. Their main vocals consist of loud, deep, guttural growls or "howls". Howler monkeys are widely considered to be the loudest land animals. According to Guinness Book of World Records, their vocalizations can be heard clearly for 3 mi (4.8 km). The function of howling is thought to relate to intergroup spacing and territory protection, as well as possibly to mate-guarding.

Guton Lake, Panama

02/28/2018