An ostrich egg, at 3.3 pounds is the largest single cell that exists
today on our planet. It's also the largest egg, and it looks about
the size of a medium cantaloupe. (Some of the dinosaurs had larger
eggs. There's a dinosaur egg in the American Museum of Natural History
in New York that's about the size of basketball.) For comparison,
the smallest bird egg is the bee hummingbird. You could put 4700
bee hummingbird eggs inside one ostrich egg. The bee hummingbird
egg is the size of a small pea and weighs .02 ounces.
Carving an ostrich egg is difficult and wears out the drills rapidly.
An ostrich egg shell has to be tough enough for a 300 pound bird
to sit on it. I've seen pictures of an adult in South Africa standing
on an unhatched egg.
The ostrich hen will typically lay 10 eggs, but some productive
hens will lay more. The hens will often lay their eggs in the same
nest as other hens, with the result that you can find as many as
50 eggs in single a nest.
Ostriches are native to South Africa, but you can find them everywhere
from Texas to Beijing. Farmers grow them for their hides, feathers,
meat, eggs, and other byproducts. They're the world's largest living
By the way, would you ever have guessed that it was the automobile
that saved ostriches from going extinct in the wild? Back at the
time of the American Revolution, a French Queen, Marie Antoinette
made a casual gesture that consigned thousands of species of beautiful
birds to extinction. She took a feather from a decorative stand
and placed it in her coiffeur. Instantly wearing feathers became
a fashion rage. Ladies throughout the world vied for the most elaborate
feathers they could find for their hairdos and hats. Hunting wild
birds for their feathers became a large scale enterprise throughout
the world. Species after species was hunted to extinction. The ostrich
feathers were particular prized because they have such a "floaty"
quality to them. The ostriches were on the verge of extinction in
the wild when an unexpected savior occurred on the scene: the automobile.
When milady was on her horse, sidesaddle, gracefully cantering across
the fields, her ostrich plume looked lovely. On the other hand,
when she was in an open automobile speeding along at 40 miles per
hour, the ostrich plume was a disaster. Ostrich feathers went out
of style, and records that still exist in the National Agricultural
Library show that the trade in ostrich feathers virtually ceased
You can tell an emu egg by it's large size and greenish black color.
It's about the size of a small grapefruit and in shape, it makes
you think of a football with rounded ends. The emu egg, by the way,
comes in several shades of greenish black. It can be fairly light
to almost black. I've seen one that was actually more blue than
The emu is a smaller cousin of the ostrich and you can find them
in Australia. It stands about six feet tall and weighs around 150
pounds. It's being grown for meat in this country. I have a friend
who grows them and she says that some can lay as many as 47 eggs,
while others lay only one or two.
The emu has a really neat defense mechanism against its predators.
An emu can only run at about 35 miles per hour, while some of its
predators -- they're cats-- can run at close to double that speed.
Nevertheless, the emus still survive. A cat may be chasing an emu
and gaining on it. The emu can't escape by flying, since no bird
weighing over 35 pounds can fly. Instead, it races along with it's
giant 9 foot long strides. As the cat is bounding full speed after
it and just about to catch it, the emu, still running along at top
speed, will raise one of its little stubby wings towards the sky
and point the other towards the earth. This makes the emu swivel
around almost 180 degrees, still at top speed, and it takes off
in a different direction. The cat can't turn this quickly and its
momentum will keep it going for 30 or so yards, by which time the
emu is far away. The emu can exhaust its predator before the predator
can catch up with it.
Emus are great natural insecticides. They eat insects and caterpillars,
and one adult emu, when killed, was found to have more than 3000
harmful caterpillars in its stomach.
By the way, I told you about how emus escape their predators by
putting one wing up and the other down and swiveling around, but
there's something else really interesting about them. They're playful
and they like people. We know a lot about how they communicate with
each other and one of their signals for, "I want to play tag," is
to thrust their breasts in a kind of scooping motion towards the
ground. When I was visiting with a local emu grower, she had me
do this when in one of their football-field size pens and then run
away from the emus. They chased after me, and then when I turned
around, they ran away from me. We continued this game of tag for
about five minutes until I was exhausted. I thought at the end of
all this chasing that they'd be afraid of me, but instead, they
came up to me and one lay her head on my arm so that I'd scratch
her neck for her.
The rheas are a South American cousin of the ostrich and they're
about the same size as an emu, that is, about 6 feet tall and weighing
around 150 pounds.
They defend themselves in a different way from the emu, though.
A rhea has a spur at its heel that looks like a smaller version
of the horn on a cow. The rhea can kick with a force of 800 pounds
per square inch, and an adult rhea has little to fear from any predator
except man. I have friends who raise them, and they tell me that
rheas are more difficult to raise then emus. Rheas can be fiercer,
less playful, and can cause you real harm if you annoy them enough.
The rhea's egg is a lovely creamy white. Like the emu egg, it's
easier to carve than an ostrich egg and it holds up better than
a goose egg.
The cassowary is a large, flightless bird native to Australia and
New Guinea where it lives in tropical rainforests. It is a member
of the Ratite family which makes it a cousin to ostriches, emus
and rheas. Like its better-known family members, the cassowary is
a powerful bird equipped with impressive defense capabilities. It
has a strong kick and sharp talons that aid in its defense.
Although the cassowary is very colorful, it can be difficult to
sight in the wild. This is especially true now that it has been
added to the Endangered Species list. It is for this reason that
only the eggs from cultivated birds are used for decoration.
An interesting thing about the cassowary is that the male is responsible
for incubating the eggs and tending the young. Females may lay eggs
in the nest of more than one male but her role is complete once
the eggs are laid.
The horn or helmet you see on the male bird pictured left is made
up of cartilage. It is thought to attract females.