Subject: Re: gray whale distribution, body shape, reproduction

Dr. Cathy Schaeff (schaeff@american.edu)
Tue, 07 Oct 1997 14:58:59 +0000

Mar2522@aol.com wrote:
> 
> I'm Carlos, I'm 12 years old and student of GFA in CT.  and I have to do  a project  about  Gray Whales , I know  the gray whales  are the smaller in the baleen whales family, but I need to know where they live?, about their reproduction, what kind  of food?, shape and all more the information as you can give to me.  I apreciate  very, very  much  all that you do for me.
> 
> Thanks Carlos.


Hi Carlos, 

Here is the information that you requested.  Good luck with your
project.



A. Distribution (where they live).

- Gray whales are found in the Pacific Ocean, the eastern P. population
has about 22000 animals and has been removed from the Endangered Species
List.
- Gray whales migrate to high-latitude (polar) feeding areas in the
summer and toward low-latitude (tropical) calving areas in the
winterover; they travel over 10,000 (6,000 mi.) each way--the longest
known migration for  any mammal; they give birth and rear young in
protected coastal bays and lagoons.

B. Reproduction

- breeding groups includes several males and one female and they may
engage in pre-mating activity for more than an hour at a given time.
- females may allow the largest and most aggressive male to mate with
her, or she may flee or roll away, she may mate with more than one male
in a single breeding season.
- females produce a single calf every one to two years.

C. Body Shape

- have a fusiform (torpedo-shaped) body shape which reduces drag whiler
swimming.
- the dorsal (top) surface is darker than the ventral (bottom) surface
(counter shading)
- have white or faintly colored markings or scars caused by barnacle
growth, shark bites, killer whale teeth marks, or from natural
pigmentation differences.
- havve four digits instead of five in their pectoral flippers; the
thumb bones are not present.
- gray whales have no dorsal finbut rather a dorsal hump followed by a
series of bumps.
- Gray whales have a narrow head with a slight curve to the jawline.
- Gray whales have about 130 to 180 baleen plates on each side. Their
baleen plates are about 5 to 25
cm (2-10 in.) long.
- gray whales have ventral throat grooves that extend from the throat to
the
flipper area or farther. These folds of skin and blubber expand the
capacity of the mouth area during
feeding.

D. Feeding

Gray whales eat about 150,000 kg (340,000 lb.) of food during a 130 to
140 day feeding period--a daily average of about 1,089 kg (2,400 lb.).
It is estimated to take 300 kg (660 lb.) of food to fill a gray whale's
stomach.

Gray whales feed along the ocean floor consuming bottom-dwelling animals
such as marine worms and crustaceans, which are abundant in ocean
sediments. Gray whales may also occasionally feed in the water column on
free-swimming crustaceans.


You can also try this site:
http://www.bev.net/education/SeaWorld/baleen_whales/reprobw.html
-- 
Dr. Cathy Schaeff
Biology Department 
American University
4400 Mass. Ave. N.W. 
Washington D.C. 20016-8007
(202) 885-2175 (phone)
(202) 885-2182 (fax)
schaeff@american.edu (email)