The Animal Kingdom
The animal kingdom is huge. It contains more
than a million species.
Most are small - much smaller than your eyes can see. But a few, like elephants
and whales, are giants. All animals have one thing in common. They cannot make
food. They need to eat plants or other animals to survive. All animals also
need oxygen to survive. Animals include everything from ants, spiders, and
worms to fish,
lizards, bears,
dogs, birds,
cats, and humans.
Those with Backbones and Those Without
An eastern ribbon snake eats a bullfrog by swallowing it whole. It will
take many days for the snake to digest the frog and be ready to eat again.
©K.Campbell/GLOBIO.org When you think of living things, you probably
think first of animals. Animals have their own Kingdom,
Animalia, which is a scientific classification.
Because the animal kingdom is so big, scientists begin by dividing it into
two general groups, vertebrates and invertebrates.
Vertebrates are animals with backbones such as humans, horses, elephants, bears,
birds, fish, and frogs. Invertebrates are animals without backbones such as
butterflies, ants, clams, and worms.
Vertebrates
Zebra lionfish have sharp venomous spines. This makes them powerful predators.
©K.Campbell/GLOBIO.org Humans have more in common with eagles, snakes,
and rhinoceroses than
you might think. This is because we’re all vertebrates, and all vertebrates
share a common design in the way they are built. Vertebrates all have a collection
of bones or cartilage called
the vertebral
column, or backbone. They also have skeletons inside their bodies that
protect their soft inner organs.
All vertebrate bodies are covered with skin. The skin may be smooth, rough,
slimy, or scaly, but it's still skin. Vertebrate skin has a covering of hair,
feathers, or scales. There are about 45,000 different kinds of vertebrates
living on Earth. Scientists have classified vertebrates into five smaller groups,
based on characteristics they share. These groups are the mammals,
birds, reptiles, amphibians, and fish.
Invertebrates
A newly emerged red-stripe butterfly rests while its wings dry.
©G.Ellis/GLOBIO.org Animals without backbones are called invertebrates.
Invertebrates are the largest group of animals. Scientists have identified
nearly 1 million different species. Insects are one of the biggest groups.
Many invertebrates have a hard or rigid outer covering. Beetles, for example,
have a hard outer covering called an exoskeleton.
Snails are covered by a hard shell.
Invertebrates that live in water, such as octopuses and sea anemones, are
called aquatic invertebrates.
Some aquatic invertebrates do not have a hard covering. They have a flexible
skin wrapping their bodies. Aquatic invertebrates range in size from plankton,
which are too small to see without a microscope, to giant squid that grow to
be over 20
m long!
The Champions of the Animal Kingdom
People are good at a lot of things, but if
animals could enter the Olympics as one team they would probably win almost
all the medals! Animals can outrun, outswim, and outjump all humans.
Young cheetahs learn to hunt by watching their mother. Later, they start
taking part in the hunt. Cheetahs are the fastest land animal and can reach
speeds of 113kph in short bursts.
©G.Ellis/GLOBIO.org Fastest Mammal on Land
Cheetahs can run up to 113
kph.
Fastest Mammal in Water
Dall porpoises can swim up to 56
kph.
Fastest Flying Bird
Peregrine falcons can dive toward the ground at more than 320
kph.
Fastest Flightless Bird
North African ostriches are the fastest birds on land. They can run at speeds
up to 72
kph. They are also the biggest bird. They can weigh 155
kg.
Fastest Fish
Sailfish can swim up to 109
kph.
Loudest Animal
The blue whale’s low-frequency pulses are as loud as 188 decibels. This
is louder than a jet engine. A blue whale’s call can be detected more
than 805
km away. On land, the loudest animals are howler monkeys. Their howls can
be heard 4.8
km away.
Arctic terns have the longest annual migration of any animal. In its life,
the average Arctic tern will travel a distance equal to going to the Moon
and back.
©M.Campbell/GLOBIO.org Longest Migration
Arctic terns migrate to and from the Antarctic - about 35,405
km round trip - each year. Among mammals, gray whales and northern elephant
seals are the migration champions. They travel up to 20,900
km round trip each year.
Deadliest Animal
Female Anopheles mosquitoes, which carry and transmit malaria,
play a role in the deaths of more than a million people each year.
Most Venomous Animal
A single sea wasp (a kind of jellyfish with 60 tentacles, each 4
m long) has enough venom to kill 60 adult humans.
Strongest Animal
The rhinoceros beetle can lift 850 times its own weight.
Longest Gestation
Asian elephants are born after a gestation period
of 19 to 22 months.
Largest Mammal
Blue whales are the largest mammals of all time and the largest living animal.
Females grow to a length of about 27
m. They may weigh well over 100
metric tons. The heaviest blue whale weighed more than 190
metric tons. The longest ever measured was more than 33
m.
African elephant bulls are the heaviest land animal. Large males may weigh
as much as 5,895kg. Despite their power and size, elephants are vegetarians,
or herbivores.
©G.Ellis/GLOBIO.org Largest Living Animal on Land
African elephants are the heaviest land animal. They are also the second tallest
land animal. Large bulls (males)
weigh more than 5,895
kg and are 3.5
m tall at the shoulder. Giraffes, which can grow to a height of 5
m, are the tallest land animals. Large males weigh more than 1,800
kg.
Smallest Vertebrate
Australia's stout infantfish, slightly smaller than the better-known dwarf
goby, is less than 1
cm long.
Smallest Bird
Adult bee hummingbirds, found in Cuba, weigh about 2
g.
Smallest Mammal
Adult bumblebee bats, which live in Thailand, weigh about 2
g.
Longest Lifespan
In the 1770s, British explorer Captain James Cook presented a Madagascar radiated
tortoise to the royal family of Tonga. The tortoise lived until 1965. It
was at least 188 years old when it died! Several Galápagos tortoises
have lived past age 150.