Which ape has male throat sacs used to make loud calls and belongs to the genus Symphalangus? The answer is Siamang.
The siamang is a black-furred gibbon and the only living species in the genus Symphalangus. Its scientific name is Symphalangus syndactylus. Siamangs are the largest gibbons, and their most recognizable vocal feature is a large gular, or throat, sac that can inflate dramatically and amplify resonant calls.
The question’s reference to males describes a familiar feature, but throat sacs occur in both male and female siamangs. They use loud calls and coordinated duets to communicate, advertise pair bonds, and help defend territories. Their calls are especially prominent in the morning and may include booms, barks, and screams.
Siamangs live in forests on Sumatra and the Malay Peninsula, across Indonesia, Malaysia, and Thailand. Another unusual feature is syndactyly: the second and third toes are partly joined by a membrane. They are often confused with other gibbons, but the inflated throat sac, large body, and joined toes are strong clues.