echolocation; swimming; breath holding by whales

From: Dagmar Fertl (dagmar_fertl@hotmail.com)
Date: Tue Mar 28 2000 - 13:26:59 EST


Dear Dagmar,

I'm Richard and i'm using my mom's e-mail. How far can a whale's
echolocation reach to find food and enemies? How fast can a whale swim away
from an enemy? How long can a whale stay under water without breathing?

Thanks,
Richard
*************************************************************
Hi, Richard. Sounds like you have a bunch of questions! I'll see what I can
do about answering them.

1. I'm not really sure how far echolocation would work. I imagine it depends
on the size of whale using it (remember, only toothed whales use
echolocation, baleen whales don't). I can tell you that an echolocating
dolphin can detect a target about the size of a ping-pong ball almost a
football field away. What we know about echolocation comes from studies of
captive dolphins, so scientists are not really sure how far echolocation in
the wild actually works and what dolphins can all do with it.

2. I imagine that a whale or dolphin swims as fast as it has to to get the
job done. If something wanted to eat me, I'm sure I could run pretty fast,
too. It's hard to measure how fast a whale is moving. A trained oceanic
spinner dolphin has been clocked in a controlled test situation at better
than 40 km/hour. Peak swimming speed of a killer whale is estimated to be
40-55 km/hour. Just remember, swimming fast takes lots of energy, so animals
won't be able to do it for long, and also, its not as easy to make sharp
turns, etc. when swimming quickly.
As a comparison to humans, the fastest Olympic swimmers swim about 2.0
meters/second, while a bottlenose dolphin can swim 1.4-3.1 meters/second and
a killer whale can average 2.4 meters/second. Mighrating bowhead whales
average 1.4 meters/second. Sprinting dolphins have been clocked at more than
7.5 meter/second...much faster than a human could ever hope to swim.

3. How long a whale can stay underwater depends on the species. A bottlenose
dolphin can stay underwater for about 5-10 minutes without breathing. A
sperm whale - the champion diver - can stay underwater for up to 1 and 1/2
hours!!

Thanks for your great questions,
Dagmar
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com



This archive was generated by hypermail 2b30 : Sat Aug 04 2001 - 10:40:12 EDT