Transcript Slide 1

Marine Birds & Pinnipeds
Chapter 8
Marine Birds
Great Frigate
http://video.nationalgeographic.com/video/player/animals/birdsanimals/seabirds/boobies_bluefooted.html
Red-footed boobies
Atlantic Puffin
(northern hemisphere cousin of the penguin)
PENGUINS
• This class includes all
birds. Birds have an
outer covering of
feathers, are
endothermic (warmblooded), have front
limbs modified into
wings, and lay eggs
Most scientists recognize 17
species of penguins:
• Emperor, king, Adélie, gentoo, chinstrap,
rockhopper, macaroni, royal, Fiordland
crested, erect-crested, Island , yelloweyed, fairy (also known as little blue),
•Magellanic, Humboldt, African (formerly
known as black-footed), Galápagos,
• Some scientists recognize an 18th
species: the white-flippered form of fairy
penguin, Eudyptula albosignata
Macaroni Penguin
Chinstrap Penguin
Royal Penguin
Fast Facts
• The average life expectancy of penguins is
probably 15 to 20 years. Some individuals live
considerably longer
• High mortality occurs among the young
• When in the water, penguins may be eaten by
leopard seals, fur seals, sea lions, sharks, or
killer whales
• In some places, such as islands in the southern
Indian Ocean, fishermen still use penguin meat
for bait
The origin of the word "penguin"
• The origin of the word "penguin" has been a
subject of debate. The theories of researchers
and historians range from references to the
amount of fat (penguigo in Spanish and pinguis
in Latin) penguins possess to the claim that the
word was derived from two Welsh words
meaning "white head". The most agreed-upon
explanation is that "penguin" was used as a
name for the now-extinct great auk, which the
modern-day penguin resembles and for which it
was mistaken
DDT
• Traces of dichlorodiphenyltrichloroethane
(DDT) and other pesticides (chlorinated
hydrocarbons) have been found in the
tissues of Adélie and chinstrap penguins.
Scientists speculate that these pollutants
were transported by ocean currents or
other animals. Their appearance in
antarctic penguins is significant in that
these toxic substances have now reached
the pristine Antarctic
Adaptations
• As in most birds, penguin
hearing is probably good,
but not as acute as that of
marine mammals
• A penguin's eyes are
adapted to see clearly
both in air and under
water
• Penguins have color
vision and are sensitive to
violet, blue, and green
wavelengths of light
CALIFORNIA SEA LION
• ORDER - PINNIPEDIA
– Pinnipeds are seals, sea lions, and walruses.
Some scientists classify pinnipeds as a
suborder of the order Carnivora.
• FAMILY - OTARIIDAE
– Otariids, also referred to as "eared seals",
include all sea lions and fur seals. Otariids are
characterized by having external ear pinnae
(ear flaps) and long flippers.
• GENUS, SPECIES - ZALOPHUS
CALIFORNIANUS
CALIFORNIA SEA LION
Habitat
• California sea lions inhabit rocky and
sandy beaches of coastal islands and
mainland shorelines. They may frequent
sandbars; sheltered coves; tide pools; and
structures such as piers, jetties, and
buoys.
Migration
• During the nonbreeding months, most
males migrate north from breeding
grounds. Southern California males
migrate to Puget Sound, Washington and
British Columbia; males from Baja
California migrate to the Channel Islands.
• Most females either stay within their
breeding grounds or move south during
nonbreeding months.
Physical Characteristics
• Male California sea lions reach about 2 to
2.5 m (6.5–8 ft.) and 200 to 400 kg (440–
880 lb.). At maturity male California sea
lions are much larger than females.
• Female California sea lions reach about
1.5 to 2 m (5–6.5 ft.) and 50 to 110 kg
(110–240 lb.).
CALIFORNIA SEA LION
CALIFORNIA SEA LION
• The foreflippers have all the major skeletal
elements of the forelimbs of land mammals, but
they are modified for swimming. The "arm"
bones are shortened, and the flippers are
lengthened by cartilaginous extensions at the
tips of the finger bones.
CALIFORNIA SEA LION
• Like land mammals, sea lions have five
digits in the hind limbs. They are
lengthened by cartilaginous extensions.
Senses cont.
• Underwater vision is acute. Like other pinnipeds,
California sea lions have rounded lenses that
allow their eyes to focus on light that is refracted
upon entering water
• On land, California sea lions have good
discrimination of bold outlines and rapid
movements. Humans approaching too quickly
will cause an alarm reaction
• Recent studies show that sea lions can
discriminate color in the blue-green spectrum;
this is probably an adaptation for their aquatic
environment
Senses
• Hearing is one of the most important senses for
a California sea lion
• Researchers believe that under water, a
California sea lion can hear sounds in the range
of 1 to 40 kHz, with a peak sensitivity of 15 to 30
kHz. California sea lions generally vocalize
between 1 to 4 kHz. The average hearing range
for humans is about 0.02 to 20 kHz.
• Hearing in water is probably acute, with good
directional ability.
• In air, a California sea lion's hearing is probably
slightly inferior to that of a human
Adaptations
• California sea lions usually stay submerged three
minutes or less; however, they can remain submerged
for as long as 10 minutes
• California sea lions, like marine mammals, have a slower
heart rate while diving. A sea lion's heart rate can slow
from about 95 to about 20 beats per minute
• The muscle of California sea lions has a high content of
the oxygen-binding protein myoglobin to help prevent
muscle oxygen deficiency
• A sea lion often regulates its body temperature by lifting
and exposing one or more flippers. The blood vessels
just under the skin dilate and absorb or release heat to
the environment.
Communication / longevity
• Sea lions have vocal cords
• A California sea lion's primary means of
communication is vocalization. Sea lions
produce sounds both above and below water
• Sea lions communicate visually, with postural
displays
• California sea lions probably live an average of
15 to 25 years. California sea lions in zoological
habitats have been known to live 30 or more
years.
Walrus
Walrus
• The common name, walrus, originated
with the Danish word hvalros, meaning
"sea horse" or "sea cow". The Russian
word for walrus is morzh. Arctic natives
call the walrus aivik (Inuit) or aivuk
(Yu'pik).
• Male Pacific walruses weigh about 800 to
1,700 kg (1,764-3,748 lb.) and are about
2.7 to 3.6 m (9-12 ft.) long.
Walrus
• Ears, located just behind the eyes, are
small inconspicuous openings with no
external ear flaps
• Walruses live to a maximum of about 16 to
40 years. (Nowak, 1999)
Walrus communication
• Walruses have vocal cords
• Walruses are among the most vocal of the
pinnipeds. They produce growls, taps,
knocks, grunts, barks, soft whistles, rasps,
and clicks.
• Walruses produce sounds both above and
below water
Elephant seal
Harbour Seal
Manatees
Manatees
• Class – Mammalia
• Order – Sirenia
– The living sirenians consist of three species of
manatees and one species of dugong
– The Greek name for this order is derived from the
sirens of Greek mythology. Sirens were sea nymphs
who lured sailors to their island with their
mesmerizing songs
– Closest modern relative: elephants
Communication
• Manatees emit sounds under water. The chirps, whistles,
or squeaks are probably produced in the larynx. They
seem to make these sounds when they are frightened,
sexually aroused, or interacting with each other.
• Vocalizations are an integral part of the cow-calf
relationship. Cows respond to squeals of their calves
from more than 61 m (200 ft.) away
• The hearing capacities of manatees are not well studied,
but it is known that manatees are adapted for hearing
low frequency sounds
• Manatees have large ear bones that are well developed
at birth. Some scientists have suggested, however, that
the main area of sound reception is not the small ear
openings but rather an area near the cheekbones. A
manatee's cheekbones are large and relatively oily, and
they are in direct contact with the ear bones
Longevity
• Manatees probably live a maximum of about 50 to 60
years
• A consequence of manatee tooth replacement is that
scientists cannot use the teeth to age individual
manatees, a procedure commonly used for many other
species of marine mammals. Scientists instead use a
method of aging manatees based on studying growth
patterns that develop on ear bones
• In early 1996, about 150 manatees died in southwest
Florida. Scientists determined the mass mortality was
caused by a red tide
• Manatees are very susceptible to cold weather
Trouble for the manatees
• Due to their dark color and because they are slow
swimmers, manatees are difficult to see in the water. At
least 20% to 22% of manatee deaths in Florida occur
from watercraft accidents yearly. Collisions with boats
and barges is the largest human-related factor causing
manatee deaths in Florida
• Although the engine propellers are dangerous, collisions
with boats cause the most watercraft related deaths. In
1995, 12 manatees expired from propeller injuries while
25 died from impact wounds. Collisions with boats cause
life-threatening internal injuries that are often hard to
locate and treat
This manatee's flipper became
entangled in a crab trap and will
require medical treatment.
Manatees’ troubles
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Flood gates and navigation locks
Poaching and vandalism
Accidental entanglement and pollution
Habitat destruction
– The human population in Florida increases by
nearly 1,000 people daily
– About 250,000 acres of forests are lost every
year in Florida and roughly one-fourth of the
state remains semi-natural
Conservation
• All four species of sirenians are
endangered or threatened
• The Florida manatee is one of the most
endangered marine mammals in the
United States
• All species of sirenians are protected to
some extent by national or local acts in
every country they inhabit
MARINE ZOOLOGICAL PARKS
• Marine zoological
parks such as
SeaWorld Florida and
SeaWorld California
help conserve
manatees. SeaWorld
is authorized to
rescue and
rehabilitate ill, injured,
or orphaned
manatees
• Having manatees at marine zoological parks
provide the opportunity for the public to learn
about these rare animals