Whales, Dolphins and echolocation

From: Phil Clapham (phillip.clapham@noaa.gov)
Date: Thu Oct 04 2001 - 09:45:13 EDT


Hi Clare:

Any good book (popular or scientific) on whales should give you
information about echolocation, so check out your library. But here are
the basics:

1) As far as we know, baleen whales (like humpbacks, blues etc) don't
have the sophisticated echolocation that many or all toothed whales do.
We don't know how baleen whales find food, though oceanographic cues,
sound and even smell (above the surface) are likely to be involved.

2) Toothed whales (dolphins, porpoises, sperm whales, beaked whales etc)
do use a very complex echolocation to find food and to navigate at short
range. In some species this is probably so sophisticated that they rely
on sight very little; indeed, in river dolphins (which forage in murky
rivers where there's little that can be seen), the eyes are not well
developed at all.

3) Whether some toothed whales use sound actively to stun prey is very
controversial, and no one knows the answer for sure. It's been
suggested that sperm whales may use concentrated bursts of sound to stun
squid or other prey, but so far this is not a theory which has strong
supporting evidence.

4) Although baleen whales don't have high-frequency sonar like dolphins,
some may use very low frequency sound to image distant objects. It's
been suggested (again, not proven) that blue whales use their very loud,
very low-frequency sounds (typically 20 Hz, 180 dB) as a way of
detecting seamounts, islands and other submarine features from distances
of hundreds of miles away. certainly these low-frequency sounds can
travel that far and further.

Hope this helps. Do a Net search on "echolocation" + dolphins,
cetaceans or something similar.

Phil Clapham

ClareBear7287@aol.com wrote:
>
> HI,
> I go to cold Spring Harbor Junior High in Cold Spring Harbor Nw YOrk, I need
> info on whales dolphins andtheir use of echolocation. Any info you could give
> me would be helpful.
> Thanks
> Clare

-- 
The Society for Marine Mammalogy will be holding its 14th Biennial
Conference from 28 November to 3 December 2001, in Vancouver, BC.  Visit
the conference Web site at www.smmconference.org for full details of
this important meeting.

Phillip J. Clapham, Ph.D. Large Whale Biology Program Protected Species Branch Northeast Fisheries Science Center 166 Water Street Woods Hole, MA 02543, U.S.A.

tel. 508 495-2316 fax 508 495-2066 email: phillip.clapham@noaa.gov



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