Subject: Migration and Why?

Phil Colla (pcolla@cts.com)
Wed, 18 Feb 1998 13:21:29 -0800

>I need info about
>where and why and which whales migrate. Is it just
>for warm water and food? Is it a built in thing like
>salmon? I hope to go to on a siteing in Seattle in July
>when I go visit my uncle.

The whales that migrate do so largely for two reasons:
mating/calving and food.  Typically, polar and high latitude regions have
excellent food supplies but the water is too cold for
young calves (with little blubber) to survive.  Equatorial
regions have warmer water, which is good for bearing and
nurturing very young calves, but food supplies are not as
rich.  So whales have adapted to moving back and forth between
food areas (polar) in summer and equatorial areas (calving
and mating) in winter.

Whales that are known to migrate with regularity include
most of the "great" whales: blue, fin, humpback, right, gray
to name a few.

Also, sperm whale adult males have a type of migration.  They
leave their groups when they reach age 4-7, and only return
when they are large enough to compete for a mate, at about age
20 or 25.  In the meantime, the females and young males do not
migrate but generally stay in one area, a group of islands perhaps.

Hope that helps.  Our web site has a little more info about
migration, but there are some portions of the site that are
incomplete right now.

Phil Colla

-----------------------------------------------------
Phil Colla, pcolla@cts.com
Humpback Whales: http://www.earthwindow.com/hwrf