Tarsiers have ultrasonic communication

A recent study has revealed that Philippine tarsiers are capable of communicating with each other via ultrasonic sounds, which are inaudible to most animal species including humans. This type of communication might have developed in order to compensate for the inefficient nocturnal vision of tarsiers and may serve as an alarm call mechanism.

It was not understood why tarsiers sometimes seemed to be yawning, as their mouths were opening but no sound was audible. By recording sounds using an ultrasonic microphone, it was discovered that tarsiers were emitting sounds ultrasonically, at a sound-level far from the range of the human ear.

The Philippine Tarsiers, which was the study species, is a near-threatened species due to extensive habitat destruction with a decreasing population trend

(IUCN, 2012)

Study Abstract

"Few mammals—cetaceans, domestic cats and select bats and rodents—can send and receive vocal signals contained within the ultrasonic domain, or pure ultrasound (greater than 20 kHz). Here, we use the auditory brainstem response (ABR) method to demonstrate that a species of nocturnal primate, the Philippine tarsier (Tarsius syrichta), has a high-frequency limit of auditory sensitivity of ca91 kHz. We also recorded a vocalization with a dominant frequency of 70 kHz. Such values are among the highest recorded for any terrestrial mammal, and a relatively extreme example of ultrasonic communication. For Philippine tarsiers, ultrasonic vocalizations might represent a private channel of communication that subverts detection by predators, prey and competitors, enhances energetic efficiency, or improves detection against low-frequency background noise."

more information:

http://blogs.scientificamerican.com/observations/2012/02/08/tiny-tree-dwelling-primate-called-tarsier-sends-and-receives-ultrasonic-calls/

article website: http://rsbl.royalsocietypublishing.org/content/early/2012/01/27/rsbl.2011.1149

references:

Dartmouth College (2012, February 8). Tiny primate is ultrasonic communicator.ScienceDaily. Retrieved February 9, 2012, from http://www.sciencedaily.com­/releases/2012/02/120208220210.htm

M. A. Ramsier, A. J. Cunningham, G. L. Moritz, J. J. Finneran, C. V. Williams, P. S. Ong, S. L. Gursky-Doyen, N. J. Dominy. Primate communication in the pure ultrasound. Biology Letters, 2012; DOI:10.1098/rsbl.2011.1149

Shekelle, M. & Arboleda, I. 2008. Tarsius syrichta. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on09 February 2012.