|Why do whales and other sea mammals breach?
|Question Date: 2004-09-23|
This is an excellent question.
In fact, it is
such a good question that scientists themselves
are still trying to answer it. And whales and
marine mammals are not the only ones who breach.
Some rays and sharks also breach. It is not known
exactly why they breach, but there are a number of
different hypotheses. One hypothesis is that they
are trying to shake parasites off of their skin.
The impact of the animal hitting the water may
have the same effect for the marine animal (whale
or ray, for example) as a dog rubbing itself
against a tree to try to scratch fleas off of its
Another hypothesis is that
breaching allows them to communicate with each
other; it is possible that the sound the animal
makes as it breaches may signal to something to
others. In fact, in some cases humpback whales
may breach more frequently in rough seas, when
their songs will be harder for other whales to
hear. They may breach simply to have a look
around at what is going on above the water (if,
for example, they hear something like boat but
can't see it). Finally, the breach may be the end
of some complicated underwater behavior that we
can't see from the surface. And of course it may
just be fun...
Nobody is sure why sea mammals breach, but there
are is evidence to support a number of good
theories. It is thought that breaching helps
remove barnacles and lice from their skin. Baby
whales that lost their mothers have been seen to
breach repeatedly--probably to send a visible and
audible signal to the mother. (Breaching is very
loud, and sound travels very well in water.)
Adults sometimes appear to breach to scare off an
intruder, and some people think they may simply do
it because they enjoy it.
That's a good question! Because we can't ask them,
we'll never really know. Scientists have many
hypotheses (or guesses) as to why whales breach.
One idea is that they are trying to get rid of
parasites or other organisms that grow on the
outside of their skin (eg barnacles). Perhaps the
parasites or barnacles cause their skin to itch,
and breaching is a way of scratching themselves
when they're far from land and the bottom is too
deep. There are killer whales in Canada that rub
themselves on smooth stones on the bottom of the
ocean, so breaching might be serving the same
Another guess as to why whales breach
is that it's fun. Dolphins definitely like to
play, so there's no reason why whales wouldn't
like to play as well. During breading season,
sometimes male humpback whales accompany female
humpback whales and their calves as they swim long
distances back to their feeding grounds. Sometimes
unattached males will try to mate with the female
humpbacks, and breaching is a way of displaying
aggression and warding them off.
breaching may be a way to communicate ("Here I am!
Over here!"), by generating a large splash and a
Scientists aren't entirely sure why whales and
other sea mammals breach. One idea is that they
do this to knock little animals and parasites off
their bodies. Another popular theory says that
they might breach simply to scratch an itch-- they
don't have arms and fingers to scratch with, so
maybe by jumping into the air and hitting the
water they can slap the itchy spot for some
relief! Of course, it's also possible that they
breach for the same reasons people do a lot of
interesting and weird things: because it's fun!
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