Transcript Orca whale olivia stacey and candice

Orca whales
DESCRIPTION
The orca whale, also known as the killer whale is a toothed whale that is a
very focused predator, even attacking enormous young blue whales. Their
only enemies are humans. Orcas live in small, enclosed pods and have 1
blowhole. The killer whale belongs to the family of dolphins and it is the
biggest.
SIZE
Orcas grow to be about 27-33
feet long, weighing more than
3600-5400 kg. The male orca
is bigger than the female.
SOCIAL
GROUPS
SKIN,SHAPE
AND FINS
The Orca's skin is mostly black
with outstanding white patches.
Orcas have rounded bodies and a
rounded head with a rounded beak.
They have a tall, pointy dorsal fin
and large, paddle-like flippers. The
dorsal fin of the male is taller
which is up to 6 ft tall and more
upright than the dorsal fin of the
female whose dorsal fin is up to 4
foot tall.
Orcas live in small groups of 6-40
whales, they are very social animals.
The bonds between the close
members of Orca groups are strong
and they last for life. The members of
a group hunt together in a very
advanced manner, attacking even a
very large prey and then sharing it.
The group members protect the
young, the sick and the hurt.
DIET AND TEETH
Orcas are task hunters that eat a very diverse diet of fish
,
squid
, sharks
, marine mammals (including
whales and seals), turtles, octopus, and birds (penguins and gulls). They
have even been known to attack young blue whales and other large
whales. They have 10-13 pairs of large, interlocking teeth in both the
upper and lower jaws. So the Orca has from 40 up to 52 teeth. That is a
total of 20 to 26 pairs of teeth.
The Food Chain of an Orca
Orca
Seal
Squid
Fish
Zooplan
kton
Phytopl
ankton
The teeth curve inwards and backwards - this helps the orca catch its
food and prey everyday. Teeth, on an average, are about 7.6 cm long and
about 1 inch in diameter, but some are even longer. Members of a group
always co-operate in hunts. An average-sized orca whale will eat 250 kgs
of food a day.
SPOUTINGBREATHING
Orcas breathe air at the surface
of the water through a blowhole
located near the top of the head.
Their blow is a single, low bushy
cloud.
SPEED
Orcas are very fast swimmers. They
can swim up to 48 km in bursts in
order to catch prey.
HEARING
Killer whales have an acute
sense of hearing, and the
auditory cortex of the brain
is well developed. killer
whales have responded to
tones within the frequency
range of about 0.5 to 125
killer hertz. Peak
sensitivity for killer whales
is about 20 kHz. Sensitivity
declines gradually above
and below 20 kHz.
VOCALIZATION
Orca vocalizations include clicks,
whistles, and scream-like pulses. The
sounds are used to communicate with
other orcas, for mating purposes, and
for locating prey. Different pods (longlasting groups of orcas) have
distinctive "accents" and can recognize
members by this accent.
HABITAT AND
RANGE
Orcas whales live in waters ranging
from tropical to arctic, and both coastal
and deep oceanic waters. They are
found in all the world's oceans and
most of the seas. Orcas sometimes
enter estuaries, but don't go far from
the sea.
LIFE SPAN:
A male has an expectancy of 50-60
years. Females have a life
expectancy of 90 years.
SOUND RECEPTION
Most sound reception, or hearing, probably takes place through the
lower jaw. A killer whale may also receive sound through soft tissue and
bone surrounding the ear. High frequency sounds in the range of 50 kHz
and higher appear to be received effectively by the lower jaw.
The fat-filled lower jawbone conducts sound waves through the jaw to
bones in the middle ears. The lower jawbone of toothed whales widens
and is hollow at the base, where it connects with the skull. Within this
very thin, hollow bone is a fat deposit that extends back toward the
auditory ear bone complex.
SOUND RECEPTION
Sounds are received and conducted through the lower jaw to the
middle ear, inner ear, and then to hearing centres in the brain through
the auditory nerve. Odontocetes can produce sounds for two
overlapping functions, communicating and navigating.
A killer whale can communicate and navigate at the same time. Sound
waves travel through water at a speed of about 1.5 km/sec, which is
four-and-a-half times as fast as sound travelling through air. The
sound waves produced by a killer whale bounce off objects in the
water and return to the killer whale in the form of an echo.
REPRODUCTION
Orca breeding occurs mostly in the winter to early spring while near the
surface and in warm waters. The gestation period is about 16-17 months
and the calf is born tail first and near the surface, usually between
October and March.
The newborn instinctively swims to the surface within 10 seconds for its
first breath; it is helped by its mother, using her flippers. Within 30
minutes of its birth the baby whale can swim. The newborn calf is about
2-2.5 m long, weighing up to 180 kg. Twins are extremely rare; there is
almost always one calf. The baby is fed with its mother's milk. The
mother and calf may stay together for a year or longer. Female orcas
reach maturity at 6-10 years old, and males at 12-16 years old.
OVERALL
Whales have sleek, streamlined bodies that move easily through
the water. They are the only mammals, other than manatees, that
live their entire lives in the water, and the only mammals that have
adapted to life in the open oceans. Like all mammals, whales have
lungs and they breathe air. They are warm-blooded, have a fourchambered heart, and nurse their young with milk from the mother.
Unlike fish which swim by moving their tail left and right, whales
swim by moving their flukes or tail flippers up and down.
CREDITS
Powerpoint presentation by: Candice,
Stacey and Olivia!
Information found by: Stacey, Olivia and
Candice!
Pictures found by: Olivia, Candice and
Stacey!
Music by: Candice, Stacey and Olivia!
BIBLIOGRAPHY
http://www.whalesfilm.com/orca.htm
http://www.worldwidewhale.com/orca.php
http://www.seaworld.org/infobooks/KillerWhale/senseskw.html
http://www.enchantedlearning.com/subjects/whales/species/Orca.shtml