GIRAFFES

I haven't told you about any African animals for a while, but today I'm going to that, and my subject is the giraffe.  Everybody knows that giraffes have really long legs and long necks.  Giraffes are the tallest animals that live on land, and they are also the biggest ruminants.  Which means they chew their cud, just like cows do.  A giraffe is 16 to 20 feet tall, and the males weigh 3,500 pounds.  Females only weigh about 1,800 pounds, but this is still a lot more than a basenji weighs, and I would not want to be stepped on by a giraffe.

Photo: Roland H.

http://www.flickr.com/photos/rolandh/

Mostly, the giraffe is not an endangered species, but there are six subspecies, and some of the subspecies are getting close to being endangered.  The names of the six subspecies are the West African, Rothschild, reticulated, Masai, Angolan, and South African.  Some scientists are now starting to think that these subspecies are actually six separate species.  They think this because of differences in the giraffes' DNA and because the different types of giraffes usually don't mate with each other, even if they live in the same neighborhood.

You can tell the different subspecies of giraffes apart by the patterns of spots they have.  The patterns of their coats are good camouflage when the giraffes are hanging out in the savannah woodlands, eating acacia leaves, which is their favorite thing to eat.

On top the giraffes' heads, there are some hornlike things, and these are called ossicones.  Both males and females have them.  The females' ossicones are hairier on top, and the male ones just have sort of bald knobs.  This is one way you can tell boy giraffes from girls, is by looking at their ossicones.

The only two gaits a giraffe can do are walking and galloping.  When they walk, giraffes move both legs on one side of the body forward, and then they move the legs on the other side.  When they gallop, they bring the back legs up to straddle the front legs, then move the front legs.  Giraffes can sprint at about 37 mph, and can keep going at about 30 mph for a couple of miles or so.

Giraffes have tough, prehensile lips and long tongues
that help them eat thorny leaves and twigs.

When a giraffe wants to lie down, he kneels on his front legs and then lowers the back end of his body.  To get up, he has to get back on his knees and then spread his hind legs to raise his rear end.  Giraffes only sleep about 4.6 hours a day, which is way less than the amount of sleep dogs and cats get, so I don't know how giraffes can even function, but somehow they do.  Usually giraffes sleep lying down, but sometimes an older giraffe will sleep standing up, like a horse does.

The neck of a giraffe can be over six feet long.  You would think that such a long neck would have lots more vertebrae in it, but this is not how a giraffe's neck is made.  Instead, the vertebrae are just longer than in other animals, like for example one vertebra could be eleven inches long.  What holds a giraffe's neck up are some really big muscles that attach to the spine.  This gives the animal a hump in the front part of the back.

Museum of Osteology
Oklahoma City, OK

Charles Darwin said that the reason giraffes had evolved to have such long necks was so that they could reach high up in the trees and eat the leaves that shorter animals couldn't get to.  And Mr. Darwin could be right about this.  But some studies have shown that giraffes with the longest necks are the most likely to die when there is a drought.  This is because giraffes with long necks need more nutrients.

So now there is another theory that says long necks evolved as a sex characteristic, because the longer the neck of a male giraffe, the more likely he would be to win a "necking" contest with another male.  These contests are how the giraffes decide who gets to mate with the females.  When the necking gets serious, the giraffes swing their heads and try to hit each other with their ossicones.  After one giraffe admits that the other giraffe is the dominant one, the two of them will often caress each other in a very sexual way.  Then the dominant male will mount the other one and even reach a climax.

Giraffes Necking
Photo by Brocken Inaglory

It turns out this same-sex activity is even more common than mounting of females by males.  Studies show that 30% to 75% of mounting is between males.  But the girl giraffes don't seem to get turned on by each other, since only 1% of them do the mounting thing.

©Longleat Safari Park

Giraffe calves are born about 15 months after the mating.  There is usually just one calf, and it comes out with the front legs and head first.  Since the female giraffe gives birth standing up, this means that the baby falls about 6 feet to the ground.  The mother grooms it and helps it stand up.  A newborn calf is about 6 feet tall, and within a few hours it can already run around.  The calf's ossicones were lying flat before it was born, but they stand up after a few days.

Adult giraffes can live as long as 25 years in the wild.  Sometimes a lion will kill one, or a Nile crocodile grabs one while it is drinking water.  But mostly, a giraffe's size, good eyesight, and strong kicks keep it safe.  Sadly, the calves are more likely to get eaten by leopards, hyenas, and wild dogs.  Probably only one-fourth to one-half of calves grow up to be adults.

Photo by Robin Moore
Giraffe Manor, Nairobi, Kenya

I think giraffes are very cool animals, and I wish we could have one of our very own.  But Mom says we can't, because we don't have any acacia trees in our back yard.  Mom has a commiphora tree in a pot, and that's another thing giraffes like to eat, but Mom says her commiphora is way too small to feed a giraffe.  Plus she likes the tree and wants to keep it.  I think this is a very selfish attitude on her part, but what can I do?  I wonder if it would help if I wrote a letter to Santa.