feeding areas

From: Jennifer Philips (jphilips@hawaii.edu)
Date: Sat Jan 26 2002 - 15:22:17 EST


I am trying to find some information on the approximate size
of the feeding
areas needed by different species of whales.

Thanks!

Unfortunately, I don't personally have information on those
numbers. It is very possible that some good estimations have
been made, based on the daily consumption of prey items by
individual whales of a species, the number of individual
whales in populations, the numbers of prey items found in a
feeding area, and the concentration of those prey items, but
that is simply too far from my area of expertise. In
general, I can tell you that whales are not confined to
"areas" as are land mammals. Because humans can not build
cities, fences, etc. in the oceans, whales are essentially
free to roam wherever they might in the pursuit of enough
food. The limiting factor for whales today appears not to be
the "area" they are allowed access to, but "how much" of
their prey of choice (for example, krill in the Antarctic)
they find in one place. Humans DO, however, have the
capability to over-fish, effecting whales by not allowing
them access to as much food as they ordinarily would have
access to.

One population of blue whales, for example, migrates to the
Antarctic ocean during the summer months to feed. Their
range in their feeding waters is essentially circumpolar,
meaning they are found off the coast of the entire
Antarctican continent. They tend to be found where krill are
found - where a large school of krill is found, so are the
whales. At the end of the feeding season, they then leave
the area entirely, and migrate back up north to their winter
breeding waters, and return again only when the summer
months return. So, as you can see, whales generally have
access to as much area as they need.

I hope I have managed to answer at least part of your
question. I would recommend further research either on
Whalenet, or try the MARMAM listserve archives at
http://www.escribe.com/science/marmam/.

Good luck!
Jen Philips



This archive was generated by hypermail 2b30 : Mon Aug 19 2002 - 10:33:04 EDT