What are those bumps on the giraffe's head?
This question was asked by my son a little while ago, and I thought it was interesting enough to merit a post.
The bumps on a giraffe's head are often mistakenly called horns, when they're actually called ossicones. (I know, don't worry...I get those mixed up all the time too.)
The ossicones are made of bone that, when the giraffe is young, are not attached to the skull, but are surrouned by small lumps of flesh-- they're free to be moved in any direction without pain to the young giraffe. As the giraffe gets older, the bones grow and fuse with the skull. (The average giraffe has two ossicones, but it is not uncommon for some to have up to five.)
Here is a skull of a giraffe that has three prominent ossicones:
(Incidentally, if you were interested in purchasing a museum-quality replica of a griaffe skull, you might want to check out this website...)
If you remember hard, you probably would recall that the tops of the ossicones look like they have little tufts of hair coming off the sides. It's actually just the males that have this look to themselves. This comes as a result of the behaviour so often observed in male animals that have anything resembling a weapon attached to their heads. They hit each other's heads with them. Eventually the flesh and skin at the top of the ossicones say, "You know what? I give up. No more skin here. It hurts too much," leaving the tops of the ossicones simply bare bone.
Now don't tell me you didn't learn anything intersting today...