Subject: Whale parenting

S. Jones (
Fri, 20 Nov 1998 14:33:07 -0800 (PST)

On Wed, 18 Nov 1998, Dayna Michaelsen wrote:

> I am doing research for a book on human parenting, and I'm hoping you can help me with the following question:  how successful are whales at raising their young to adulthood?  In other words, do they have a high or low mortality rate (especially compared to humans)?  I would really appreciate any help you could offer, and I thank you for your time.
> Dayna Michaelsen
Dear Dayna,

The only reason to compare whales to humans is that they are both mammals.
Comparing maternal strategies across animal species is more valid than
comparing maternal strategies between animals and humans.  Whales are
completely different than humans, the most striking difference (besides
species) is that one lives in a completely aquatic environment, while one
is completely terrestrial.  Therefore, each species has developed to
specifically adapt to their surrounding environment.  I do not think you
should compare whales to humans.  Perhaps you could compare whales to
dolphins or whales to seals or sea lions - all are marine mammals.

The answers to your questions about whales are as follows:

Most whales do not raise their young (calves) to adulthood.  Rather, the
young whale stays with its mother for 2-3 years before it leaves.  One 
exception is the killer whale, whose female young stay with their
mothers for their entire lives.  When the female gets pregnant again, she
cannot be looking after two young at the same time.  During the time the
young whale stays with its mother, it grows and learns the skills it needs
to survive by itself.  It is difficult to say what the mortality rate of
calves is.  This is because scientists cannot keep track of all the whales
that roam the oceans.  The only way to tell if a calf dies is if
scientists are closely following a mother/calf pair, or if the calf washes
up on the beach.  I do not know the statistics for infant mortality rates
in humans, so I cannot compare them to the mortality rate of calves.

I hope this information helps you.