Opening Graphic for Gallery
We all recognize those cute tuxedo-clad stars of hit movies such as
Happy Feet but let’s go a step further
and find out just what makes
Penguins’ Rock! The newest addition
to the Tennessee Aquarium’s array of
world class exhibits takes you miles
south of the equator to a chilly world of
ice and snow. Take a stroll through the
exhibit and discover the top 10 reasons
penguins rock!
There are 17 species of penguins all of which are found only in the southern
hemisphere. Despite media claims, penguins and polar bears do not coexist. Most live
in cold water but some species, such as the Galapagos penguin, inhabit temperate
waters near the equator. The two southernmost species, the Adelie and Emperor,
breed only on the continent of Antarctica. Penguins’ Rock will feature the Gentoo
and Macaroni penguins.
Antarctica is inhabited by penguins, seals, and
other plant and animal species. All of these life
forms live without the company of humans.
Antarctica is protected by the Antarctic Treaty,
an agreement that bans all military activity,
nuclear testing and radioactive dumping. Exploration continues in the area and currently seven
nations claim parts of its territory. Those countries are Argentina, France, Australia, Chile,
New Zealand, Norway, and the United Kingdom.
Penguins range in size from the large
Emperor penguin that can reach 4 feet in height
to the little blue penguin that grows no larger
than 16 inches. Gentoo and Macaroni penguins
are mid-size birds that grow on the average 2430 inches.
Penguins are flightless birds covered with more feathers than most other birds.
In fact, penguins have nearly 80 feathers per square inch. Their small, stiff feathers
are so tightly packed that they provide the waterproofing necessary for survival. Once
a year, penguins molt all their feathers. During
their molting period, penguins do not enter the
water to feed; therefore, the birds must build up
stores of fat to provide their energy until molting is
complete. Like other birds, penguins have an oil
gland near the base of their tail that excretes oils
used during preening to keep the water out and the
warm air close to their body.
In the Antarctic, water temperatures can
reach 28oF and air temperatures can reach -80oF.
While dense waterproof feathers provide nearly
80% of their insulation, penguins also have a thick
layer of fat or blubber to help them stay warm.
They maintain an internal body temperature of
102o F. While on land, their dark back color absorbs heat from the sun and they huddle
in large groups to conserve heat. Guests to Penguins’ Rock will be offered a chance to
experience the chilly water penguins live in by reaching through an opening in the
rocks. The water temperature will be between 45-48oF in this exhibit.
The penguin “tuxedo” provides camouflage called countershading. Viewed from
above, the back blends into the dark ocean,
while the lighter belly helps the penguin
blend into the surface when viewed from
below. Penguins generally live in areas
with few if any land predators due to their
inability to fly. On land, eggs and chicks
may be preyed upon by predatory birds such
as skuas and gulls. Unfortunately, penguins
now face threats from introduced land species such as rats, cats and stoats (a weasel
relative). At sea their coloration protects
them from leopard seals, sea lions, sharks
and killer whales.
Penguins cannot fly but they can speed through the water like tiny torpedoes.
The penguin’s streamlined body and strong flippers allow it to slice through the water
with ease. Penguins are highly adapted swimmers capable of reaching speeds up to 20
mph. The fastest Olympic swimmers can reach speeds of just over 5 mph in a 100meter race. Emperor penguins are capable of diving to depths of 900 feet. Penguins
breathe by “porpoising” like dolphins as they swim. While penguins are speedy in the
water, on land they are much slower. They can waddle about 2 mph and some species
are capable of making long treks up to 20 miles to nesting sites.
Penguins have a good sense of hearing using ears located under their feathers.
Penguins use calls to communicate and help recognize mates and chicks. Penguins
also demonstrate many physical behaviors to communicate. The ecstatic display is
seen among males attempting to attract mates. Males raise their wings and produce
repetitive calls. Mouth gaping is a way to tell another to “stay out of my territory.”
The sideways stare is a way to threaten an approaching penguin or can be used by a
female when approaching a single male. Bowing between pairs helps establish a bond.
Penguins have a poor sense of taste and smell. They can see equally well on
land and in the water. Their eyes are protected by a third eyelid called a nictitating
membrane. Penguins often sleep on land, either standing up with their head tucked
under a wing or lying down. They also sleep while floating at sea. Emperor penguins
are thought to be the longest lived species living to 50 years but generally most penguins live between 10-20 years. Most larger species reach sexual maturity in 5-8 years
while smaller species reach maturity in 3-5 years. Penguins are not sexually dimorphic. The sexes look similar, although in some species males tend to be heavier than
females. Most zoos or aquarium rely on DNA tests to determine sex.
Penguins are great parents. Most penguins are monogamous and courtship
displays vary among the species. Penguin parents living in cold climates hold their
eggs and/or chicks on their feet and cover them with their feathers to stay warm and
safe. Incubation time for penguins ranges from 65 days for Emperors to 33 days for
little blues. Gentoo penguins nest in snow free locations. They lay 2 eggs that require
34-36 days to hatch. The eggs are attended to by both parents. Macaroni penguins
nest on the ground using pebbles, sticks or feathers. Two eggs are laid but generally
only one survives. Both of these parents also tend the eggs for 33-37 days. Penguin
parents feed their babies regurgitated food and protect them until the babies molt and
their waterproof feathers grow. The chicks remain with their parents for about 25
days, then they join other chicks in groups called crèches. Penguin parents can identify
the call of their own baby among the calls of all the babies in the colony.
Penguins are fantastic fishermen. One penguin can eat more than ½ pound of
raw fish each day. Penguins feed out in the ocean. Their sharp beak catches the fish
with ease and their backward pointing tongue spines keep a good grip on their prey
and the penguin swallows the fish whole under water. Penguins in the wild eat squid,
fish and krill. Krill is an important food source in the Antarctic for many whales, seals,
fish and seabirds. It is estimated that these predators consume over 300 million tons of
krill per year. Scientists estimate that the oceans may contain nearly six billion tons
of krill. (Sea World, 1992) Eating raw fish every day means that penguins excrete
strong-smelling waste.
Penguins need your help! Penguins face many survival challenges including
habitat loss, oil spills, reduced food supplies and climate changes. Introduced species
prey on eggs and young chicks. The most endangered species of penguin is the
Galapagos Penguin. Habitat destruction and loss of nesting grounds has caused the
population to plummet to just 600 breeding pairs. All 17 species of penguins are protected by law from hunting and egg gathering. You can help protect penguins around
the world by supporting conservation initiatives for penguins and other marine life.
The chart below lists the penguins in order of their population of breeding pairs from
highest to least.
Macaroni – 9 million
Chinstrap – 4 million
Rockhopper – 3.7 million
Adelie – 2.6 million
King – 1.6 million
Magellanic – 1.3 million
Royal - 850,000
Little – 600,000
Gentoo – 314,000
Emperor – 175,000
Erect Crested – 80,000
African – 59,000
Snares – 30,000
Yellow Eyed – 3,587
Fiordland – 3,000
Humboldt’s - 3,000
Galapagos - 600