Acoustical Studies

Sound production is common among mammals. The most obvious purpose for these sounds is communication. Elaborate communication is a common phenomenon among higher order species and species with complex social structures. Another purpose for sound production is echolocation, a phenomenon found only in bats and toothed whales.

Members of the UHCL Dolphin Research Team, under the supervision of Prof. Michael Hunt, have initiated acoustical studies with marine mammals. To establish a database, they have collected samples from dolphins in rehab over the last three years. This includes Big Al, Cupid, Emma, Memory, Harley, and Noah, representing four species from the delphinidae family. This limited data and data from other sources certainly verify that interspecific identification is possible, i.e., a species can be identified by acoustics.

Intraspecific distinctions can also be made. This means that individuals like Cupid and Emma could be individually identified by audible patterns as well as by sound analysis. Each bottlenose dolphin also seems to have a signature whistle, and this could be true of other species as well.

There are preliminary indications that symptomatic patterns are possible. Big Al and Louis’ whistles appeared to be monotone, and there were limited variations in other sounds. For instance, Big Al seemed quiet most of the time, not echolocating like many other bottlenose. Memory, a melon-headed whale, has an apparent unique acoustical characteristic. In addition to apparent whistles and echolocation clicks, she produces an unusual popping sound, usually singularly rather than in a series. It is not totally unlike the popping sound Emma made, although it does not seem to be a common sound in bottlenose dolphins. The question remains as to whether these sounds are unique to the species, unique to Memory, or symptomatic of a physical condition. The acoustical studies are ongoing. Four reasons for the studies are as follows:

a. A possible diagnostics tool;

b. Follow-up studies – signature acoustics that may help us track released animals;

c. The collection of acoustic samples from Gulf of Mexico species;

d. An enhancement to behavioral studies.

Samples of Big Al, Cupid, Emma, Memory, Harley, and Noah will be placed on the UHCL Dolphin Research Team webpage in the near future.

You can also contact Prof. Hunt at huntm@uhcl.edu