Subject: Killer Whales

Kim Marshall (kimm@oceanalliance.org)
Sun, 31 Oct 1999 18:40:02 -0500

>Reply:  Dear Kari,
In an attempt to answer all your questions I have listed general
information about orcas or killer whales below:
-Live throughout the world, only hampered by ice (limitation to air) and
lack of food.
--Males grow to approx. 8.2 m, max 9.8 m.  Females generally grow to 7 m,
with a mx of 8.5.  Mature males, dorsal fin can grow up to 1.8 m
--pregnancy lasts about 17 months.
--captive calf mouthed solid food at 3 months, ate some at 5 months and ate
at the adult rate of 5% body weight at 9 months.  May have continued
nursing til 15 months.
--Sexual maturity.  Males 5.2 to 6.2 m long, and a growth spurt occurs at
this time.  Females 4.6 to 5.4 m long.
--4-5% annual birthrate.  Calving intervals 3 to 8 years, may be on the
higher end depending on density of the particular pods.
--carnivorous and opportunistic feeders, diets differ seasonally and
regionally.  Seems to be no marine animal safe from attack.  They attack
other cetaceans, pinniped, penguins and other sea birds, sea turtles, many
kinds of fish (esp. herring and salmon) and even their own.
--Pod size can measure from 1 to 100 or more animals, but group of 5 to 20
are more common.
--It is thought that killer whales remain with their mother's pod, until
the matruirch dies, and then the pod may split as the other females become
more independent.
--Commercial whalers generally do not directly go after killer whales.
They may catch them while in the persuit of larger animals.  Norway has the
most documented kills.  They believe that killing the whales will help
raise the fish stock.
--newbprns 2.1 to 2.4 m long and about 180 kg
--females dorsal fin modestly falcate and less than 1 m tall.
--flippers are shaped like broad rounded paddles
--calves, white areas are more tan or brown
--there are a few all black and all white killer whales that have been seen.
--most calves are born in autumn
--10-12 teeth perside of each jaw (40-48 teeth)

Killer whales (Orcinus orca) are a cosmopolitan species of whale. They can
be found in polar regions and in equatorial regions. Their distribution
worldwide is dependant upon prey availability, human predation and
environmental factors like ice cover. They are most abundant within 300 or
so miles of continental coastlines and may be found in all oceans any time
of the year.

Resident populations can be found in places like Washington State, British
Columbia and SE Alaska.

For more information search WhaleNet's book page at
http://whale.wheelock.edu/whalenet-stuff/ed_resources.html#biblio and links
to WhaleNet.  Also try the Free Willy Keiko Foundation
(http://www.keiko.org/home/trainer/list.html).  Good luck! Kim

Question:
Hi, i'm doing a paper on killer whale populations.  i was wondering if
>you had any graphs or other resources where i could find the population
>of killer whales from 1990 to 1999 in the pacific ocean.  i was also
>wondering if you knew the estimated doubling time, or the estimated
>extinction of these mammals.  I was also wondering if you could possibly
>tell me what killer whales eat, if their population is at homeostasis
>and if they are at or close to their carrying capacity.  Oh, and one
>last question.  Do they disperse actively or passively??  I would really
>appreciate some answers or resources as to where i can find these
>answers.  Thank you so very much.
>

Kim Marshall-Tilas
Whale Conservation Institute/Ocean Alliance
191 Weston Road
Lincoln, MA  01773
(781) 259-0423
fax: 259-0288
website: http://www.oceanalliance.org