Marine mammals such as dolphins and whales use sound to communicate, locate prey, navigate, and avoid predators. Today, a lot more is known about the types of sounds these mammals use in order to communicate with each other.
But how do manatees communicate?
What are their different vocalization patterns?
Although they are also marine mammals, manatees socialize and communicate very differently from other marine mammals. Along with dugongs they are the only herbivorous marine mammals in the world and the closest relatives to the largest land mammals, elephants. Often described as semi-social, very little is known about their acoustic behavior and whether they use sound as a form of communication.
|DSG Acoustic Recorder|
To help us understand how these agile species use sound, we placed a DSG (digital spectrogram) acoustic recorder in Great Harbour Cay marina. The acoustic recorder was programmed to record the low frequency sounds produced by manatees, which are often described as chirps, whistles, or squeaks. Scientists have been able to link some of their sounds to represent signs of aggression or fear (Listen to Manatee Sounds). Mother and calf pairs are known to share the most vocalizations patterns although an increase in vocalization patterns have also been heard between different age classes during socializing behaviors such as rolling, pushing or embracing (MANATI).
Much like how dolphins can be identified from their signature whistles, scientists will be looking at identifying individual manatees from the sounds they produce. In February 2012, while Rita and Georgie were at Dolphin Cay-Atlantis we recorded their vocalizations to compare those vocalization patterns to those recorded of them in the wild.
Below are the acoustic profiles for three types of sounds detected, while recording Rita and Georgie on May 1st, 2012.
|Sound Category: Creak|
|Sound Category: Scream|
|Sound Category: Whistle|
MANATI, S. D. (n.d.). Animal Bioacoustics . Retrieved May 23, 2012, from Caribe Bioacoustics and Noise (CABN): http://www.cbanpr.com/manatee.html
Listen to Manatee Sounds. (n.d.). Retrieved May 23, 2012, from Save the Manatee Club: http://www.savethemanatee.org/audio.htm
Manatees, Bioacoustics and Boats: Hearing tests, environmental measurements and acoustic phenomena may together explain why boats and animals collide