curious question
-
by
mistyfriday
These gazelles with the bent horns have always raised my curiosity. Are the horns hard, soft, or in-between? Do they thicken up or stay the size we see them? Do they grow into a bent shape or suffer an injury bending them?
Posted
-
by
davidbygott
moderator
Good question. The horns are hard - as in all bovids, a bony outgrowth of the cranium surrounded by a keratinous sheath. They don't get any thicker - if you see a tommy with short thick horns, he's a young male. Most descriptions of the species state that the horns are often "deformed, broken or absent". One interpretation is that there is not much selection pressure for female tommies to have good functional horns - that evolutionarily, they may be in the process of losing them, as impala and dikdik females have done. Males need horns for territorial fighting, but females would only use them for defending their fawns, and when you are as small as a tommy, what good does that do? Jackals usually hunt in pairs, so although a tommy female may try to drive a jackal away with her horns, one jackal distracts the female while the other steals the baby; end result, Jackals 1 - tommies 0. All the other predators are bigger than tommies and it makes more sense for the mum to run away and the baby to lie as still as it can to avoid detection. That's my take, anyway.
Posted