Re: bottle-nosed dolphins

From: Cathy Schaeff (schaeff@american.edu)
Date: Fri Apr 12 2002 - 09:32:26 EDT


Hi,

A quick summary of dolphins' senses goes as follows:

1) Sight: reasonably good, but nothing special in most species - because
light doesn't travel very far underwater (especially where the water is
productive and full of plankton). In river dolphins sight is very poor,
since they live in murky rivers and rely a lot more on echolocation.

2) Hearing: acute in all species, though it varies from one to another.
Some large whales (e.g. blues) can hear very low frequencies, well below
what we can, while others (e.g. dolphins) can hear at higher frequencies
than humans.

3) Touch: probably pretty good in all species.

4) Smell: complicated by the general inability to "smell underwater". A
sense of smell is probably almost absent in toothed whales like dolphins
(they have echolocation, so don't need smell to find food). It's
probably quite good in baleen whales - the olfactory lobe of the brain
is well developed, and they seem to have all thenecessary hard wiring in
their "noses". I suspect they use it to find prey patches upwind when
they're at the surface.

5) Taste: who knows? Probably well developed.

6) Echolocation: exists in toothed whales, and is highly developed in at
least some. This is biological sonar - sending out clicks or other
sounds and reading the echoes as they bounce off objects. Very much
like bats, and the primary tool for dolphins, porpoises, sperm whales
etc in finding food. Bear in mind that light doesn't penetrate water
very well, and beyond about 600 feet down it's pitch black, so sight is
useless at depth (and sperm whales can dive to at least 7000 feet).

There is a lot of additional information about dolphins and whales on the
internet and lots of pictures too. You can start by going to "How to Find"
(http://whale.wheelock.edu/howtofind.html) page on WhaleNet.

Good luck,

Cathy

-----Original Message-----
From: CutiePrncss25@aol.com <CutiePrncss25@aol.com>
To: schaeff@american.edu <schaeff@american.edu>
Cc: CutiePrncss25@aol.com <CutiePrncss25@aol.com>
Date: Thursday, April 11, 2002 6:57 PM
Subject: bottle-nosed dolphins

>I'm sorry for bothering you but I'm doing a report on bottle-nosed dolphins
>and I was hoping you could answer these questions, If you have time.
(Send
>photos, please)
>
>1. How many senses do dolphins have? and what are they?
>
>2. Can you give me some facts?
>
>3. About the baby whales?



This archive was generated by hypermail 2b30 : Mon Aug 19 2002 - 10:33:04 EDT