Subject: Breaching Whales

Phillip Colla (oceanlight@oceanlight.com)
Sat, 12 Jun 1999 19:01:10 -0700

>Also do all whales breach?

It depends on how you define the term "breach".  Some people
consider any behavior in which a whale breaks the surface of
the water to be a breach.  Defined this liberally, most
cetaceans breach.  I believe, though, that this is not exactly
what you meant by "breach".

Most people consider a breach to be a behavior in which most
or all of the a whales body leaves the water.  Here's a good
example of a full breach:

   http://www.oceanlight.com/assets/images/0205.jpg

Of the great whales, I know that humpback and southern right whales
breach often.  I have seen gray whales breach a few times when they
are migrating, and I understand they commonly breach when they have
reached the calving lagoons in Mexico.  I have seen blue whales partially
breach (past the pec fin) a few times, and I know of accounts where
observers have seen them breach repeatedly.  I know (firsthand and
by reading) that sperm whales commonly breach.  I have seen photos
of breaching fin whales, although I hear this is not common.  Orca
breach often as well.

Of the smaller whales (false killers, pilots, melon headed and various
beaked whales, minkes, etc) I think that breaching is seen, but not
often.  But I do not have much personal experience here.

Of dolphins and porpoises, breaching is common in the sense that
dolphins often leap clear of the water.  In fact, there are circumstances
(traveling at speed) in which it is more efficient for a dolphin to
repeatedly leap clear of the water than to swim underwater continuously.
Spinner dolphins (and some others) often leap clear of the water and
spin or twist, landing every which way back into the water.

There are behaviors that qualify as "partial breaches".  For instance,
here are head lunging humpback whales. (While I don't consider a head
lunge to be a "proper breach", it is true that the whale is "breaching"
or breaking the surface of the water):

  http://www.hwrf.org/hwrf/assets/images/lunges.jpg

Here is an example of a humpback whale "head slap".  In this behavior,
the whale does launch itself almost all the way out of the water, but
instead of twisting as in a "proper breach" the whale falls forward
and lands on its chin and throat:

  http://www.hwrf.org/hwrf/assets/images/389.jpg

The real interest is in what these different forms of "surface breaching
behaviors" mean.  Why do the whales do these things?  Does a breach
mean one thing to a solitary whale than it does to a whale in the middle
of a humpback competitive group?  Researchers are asking these questions,
and the answers (they are slow in coming) differ for different species
and just lead to more questions.

Phillip Colla, http://www.oceanlight.com
oceanlight@oceanlight.com   or pcolla@cts.com