Subject: Gray Whales

Lindsay J Porter (h9390327@hkucc.hku.hk)
Sun, 5 Apr 1998 19:53:14 +0800 (HKT)

>Hello I have a few questions for you...My little cousin is doing some
>reseaarch on the gray whale. I have a questions that we could not find.
>
>1. Do the gray whales have a difficult time finding mates? Why?
>
>2. What is the total Population of the gray whale?
>
>What is the ratio...Birth to death..
>
>
>Thanks for your time I hope I hear from you very soon.
>
>Brgds Mr. O'Connor

Dear Mr O' Connor,
Gray whales do not appear to have a difficult time finding mates -
post-whaling protection has seen a good recovery of the remaining population
as a rate of 2.5 % per year (sorry, this is the best birth/death rate ratio
equivalent I could find).  The total poopulation of the Gray whale is
belived to be 15-22'000 individuals (1990) - a western Pacific stock
believed to be near a non-viable population level numbers approx. 100
individuals. 

Following Information Taken From
http://www.oit.itd.umich.edu/bio/Chordata/Mammalia/Cetacea/Eschrichtiidae.shtml

The Gray Whale
This family contains a single living species, the gray whale. These whales
are restricted today to the north Pacific (along
east and west coasts); Atlantic populations are extinct.

Gray whales are large whales, ranging to over 14 m in length and over 30,000
kg in weight. They have a slender body
with a low dorsal hump and no dorsal fin. The flippers are broad, and the
tail has a folded ridge on its dorsal surface.
The throat has two or three short grooves, unlike the multiple grooves of
rorquals.

The skulls of gray whales differ from those of rorquals in that the
telescoping of the bones that make up the dorsal
surface is not as extreme. The nasals and nasal processes of the premaxillae
extend posteriorly beyond the anterior
border of the supraorbital processes of the frontals; the maxillae possess
nasal processes; the nasals are large; the
frontals are broadly exposed on the dorsal surface of the skull; the
supraoccipital does not extend anteriorly beyond the
zygomatic processes of the squamosal; and the rostrum is narrow and arched.
The baleen plates are short and narrow.

Gray whales feed by swimming on their sides along the bottom, gulping mud by
expanding their oral cavities rapidly
(creating a strong inflow), and straining it through their fringed baleen
plates. A wide variety of invertebrates is taken, but
crustaceans are the main source of nutrition for this species.

Like rorquals, gray whales are migratory species. They summer at high
latitudes in the Pacific, migrating during autumn to
the west coast of Baja California and the south coast of Korea. Pregnant
females gather in shallow lagoons to give birth
to calves. Gray whales travel singly or in small groups of up to a dozen or
so individuals.

Populations of this species were nearly driven to extinction in the early
part of this century. Protected from whaling, the eastern Pacific population
has made a strong comeback.
email h9390327@hkucc.hku.hk
Dolphin Research Group
The Swire Institute of Marine Science
The University of Hong Kong
Cape d'Aguilar
Hong Kong
website: http://www.webdivers.co.uk/dolphin/index.html