Subject: Re: Migration

Phil Clapham (phillip.clapham@noaa.gov)
Wed, 13 Oct 1999 08:48:33 -0400

Greetings:

Hard not to reply to such a cheery and entertaining message!  Let's
see...

Here are some papers that you may be able to find that deal with this
(sort of):

Kawamura, A.  1975.  A consideration on an available source of energy
and its cost for locomotion in fin whales with special reference to the
seasonal migrations.  Sci. Rep. Whales Res. Inst., Tokyo 27: 61-79.

Lavigne, D.M., Innes, S., Worthy, G.A.J. & Edwards, E.F.  1990.  Lower
critical body temperatures of blue whales, Balaenoptera musculus.  J.
theor. Biol. 144: 249-257.

Kshatriya, M. & Blake, R.W.  1988.  Theoretical model of migration
energetics in the blue whale, Balaenoptera musculus.  J. theor. Biol.
133: 479-498.

Brodie, P.F.  1975.  Cetacean energetics, an overview of intraspecific
size variation.  Ecology 56: 152-161.

Brodie, P. & Paasche, A.  1985.  Thermoregulation and energetics of fin
and sei whales based on postmortem, stratified temperature
measurements.  Can. J. Zool. 63: 2267-2269.

Brodie, P.F.  1977.  Form, function and energetics of Cetacea: a
discussion.  pp. 45-58 in ed., Functional anatomy of marine mammals. 
Academic Press, New York.

I suspect you'll have a hard time finding some of these in Colorado, but
the Brodie paper in Ecology is a key one and that should be easy.  Same
for the Kshatriya and Blake in the Journal of Theoretical Ecology.

The problem with migration is that we really don't know why whales do it
(given the central role which migration plays in the life cycle of these
animals, this may sound too stupid to be true, but actually it's both:
stupid and true!)  Brodie has the leading theory, but the problem is
that many of the values for key elements of the various energetics
equations are poorly known, so you can almost make them come out any way
you want depending on what numbers you plug in.  It is clear that the
seasonal buildup of lipids in the blubber during summer feeding acts as
a reserve to get the animal through prolonged periods of fasting during
winter migration, but that still doesn't tell us why they travel so far,
and to areas without food, in the first place.

One caveat about whale migration generally: it's not nearly as simple as
we used to think.  Even in humpbacks, it's becoming evident that not all
animals migrate every year.  In some species evidently only portions of
the population migrate (e.g. right whales --> mostly parturient females,
though where the rest of the population goes in winter isd anyone's
guess).  My main criticism of existing migration models is that they
look at the topic from a population perspective, when migration is
fundamentally an individual-based decision which will almost certainly
vary by age, sex, reproductive condition etc (given that energetic needs
and potential for reproductive success aren't the same for different
age/sex classes).

Hope this helps - it's not exactly a crystal clear topic.

Phil Clapham

P.S. And concerning your missing the Sea, I can relate.  Being inland
for long periods produces a kind of terrestrial claustrophobia.

	"Beware of love, for it is a wide, wide sea.
 	Beware of the Sea, for it is a wide, wide love."
					Madriaga


meredith canode wrote:
> 
> Dear distinguished Whale gurus,
>           I am a senior year zoology student at Colorado State University
> who has spent many summers lifeguarding on Cape Cod. I miss the ocean more
> than I can bear and look forward to moving to a coast soon. I hail from the
> east and consider it my home and have developed an ongoing love of the ocean
> and of whales. I have been researching whale migration, and while I have
> found no problems in finding information on where whales migrate to; I have
> found little if no information as to how they manage such trips
> physiologically. I was curious as to what adaptations in their morphology
> would allow such extensive trips. Any information you could grant me would
> be greatly appreciated. I hope to go into a field of marine mammal
> veterinary medicine (yes, just a little bit specific). Are there any
> recommendations of top notch educational instituitions that offer such a
> program. I have heard of UC Davis and Santa Cruz. Any advice for my future
> career would be greatly appreciated. I would also like to say I admire and
> appreciate what you do; it is of great importance.
> 
> Thankyou for everything
> Meredith Canode
> 
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com

-- 

Phillip J. Clapham, Ph.D.
Large Whale Biology Program
Northeast Fisheries Science Center
166 Water Street
Woods Hole, MA 02543

tel (508) 495-2316
fax (508) 495-2066
Internet: phillip.clapham@noaa.gov