Every other grazing animal I can think of has antlers or horns. Yet the horse/zebra/donkey family has nothing but the fantasy unicorn.
Dennis
Pigs, tapirs, camels, hippos, llamas - all grazing animals( yes, pigs can and will graze )with no horns or antlers. It’s not as rare as you think.
Best we can tell the common ancestor(s) of the horses, tapirs and rhinos did not have horns. The rhinos( and not all rhino lineages, just the currently extant one )developed some secondarily out of keratin rather than bone. The horses and tapirs did not, far as anyone can tell. Some individual horses do develop small bony protuberances on their skulls, but they are probably just that and not the nubs of horns left from previous horned ancestors.
Using nominal classifications, cattle and deer are even toed ungulates. Others in that group like camelids, hippos an pigs have been mentioned, but there’s also peccaries.
Many deer and deer-like animals have no horns. And in some species it’s sex-based. So more having to do with mating than eating.
Giraffes do not have true horns.
Cetaceans are an evolutionary offshoot of those and they certainly don’t have horns. (Narwhals have an extended tooth.)
The equids, rhinos, etc. are odd toed ungulates. None have true horns so no clear advantage in terms of grazing or else some in that group would have evolved them.
I’ve heard this before.
If those things on a giraffe’s head aren’t horns what are they and what’s their proper name?
Our vocabulary word for the day is “ossicone.” The difference appears to be that ossicones are made of cartilage, rather than bone, as antlers are, and that they remained covered with skin and hair.
Horses use their speed to run away from predators. Horses with horns or antlers would be slower when running away from prey and be at an evolutionary disadvantage.
Mooses have horns. Did not seem to be an evolutionary disadvantage for them.
Members of the deer family have antlers. While antlers “function primarily as objects of sexual attraction and as weapons in fights between males for control of harems” (Wikipedia), they also have a role against predation:
I would speculate that their relative natural environments might be a factor in why deer have antlers and horses don’t. Wild horses prefer wide open spaces for defense purposes, such as plains, prairies, and steppes, while deer are found in more mixed environments. For example, one might find a deer in a forest or woodland, but a wild horse less likely so.
Therefore, I’d guess that in the “fight or flight” scenario, the horse puts all its eggs in the “flight” option - although it does have a powerful rear kick - while staying in wide open spaces to spot predators from a distance. The deer family I’d guess are still mainly weighted towards “flight”, although stags with antlers could choose to fight wolves and protect other herd members. I’d also guess that cows are weighted a bit more towards “fight”, in numbers and in a herd mentality.
Why don’t they have back-up beepers?
Yeah? Where do baby giraffes come from, then :dubious: ?
Moose are bigger than wild horses - predators are a little more reluctant to go after them due to size.
But, beyond that - antlers and horns are metabolically costly to grow, especially antlers. If horses didn’t use them for mating rituals (as deer and their relatives do) then they might be better off saving those nutrients and energy for other purposes.
Because they don’t need them.
Why don’t horses have horns?
because you can just shout “get out the way”
sorry
If you have to do it in 10 words or less, I think a better answer is “because their ancestors didn’t have them”.
Video of how a moose responds to a bear:
Video of how horses react to a bear:
Moose are fighters. Horses are runners. When you’re running away, horns would just be liable to catch on things.
Yet moose is the basic staple food source of both bear and wolves, especially in places like much of Fennoscandia, where there are (or historically were) no other large herbivores around.
Horses don’t have horns because their hooves are too big to work the keys.
They make bitchin’ drummers, though.
Just-so story, ten yard penalty.
The problem with trying to “interpret” evolution is that evolution is randomness driven by environment; we humans like narratives, so we imagine that the environment shapes optimal survivors like a craftsman. The extreme end of this is Lamarckism, where giraffes have long necks because their parents strained their necks trying to get at those juicy leaves and this stretched out their genome like silly putty. Darwinian evolution has a much greater role for chance: Giraffes have long necks because some giraffe ancestor happened to have a mutation which gave it a somewhat longer neck, and that ancestor happened to be more successful at making children. Had the ancestor mutated to eat a slightly wider variety of food, instead, and that gave an advantage, long necks wouldn’t have happened.
Or giraffes might have gone extinct. It happens, you know, and not just because of humans.
Just remember that ecosystems can’t say ain’t: You see what exists, not what could have existed, and not what used to exist, unless that history created an actual fossil we can interpret. You also don’t see things which would be better in some way, even if they would be a lot better; the major example of this is the whole Carboniferous period, when trees existed but nothing which could rot dead wood did, so the dead wood just sat around, not getting rotten, a horrible violation of arbitrage which eventually resulted in lots and lots of coal.
Are you talking pre-history or during human times? If you’re talking about the human era, horses wouldn’t be roaming free for the most part.
One should also note that evolution is a big believer in “good enough”. Saying that because X species does a better job of avoiding bears then Y species should use the exact same methodology relies on there being an actual Mother Nature who is logically approaching the problem. All that’s required for a less-good strategy to propogate is for it to be good enough against bears that Y species is able to keep making more baby Ys from generation to generation.
Granted, if horses and moose are in competition for resources, then any significant advantage that one species would have would cause it to devour most of the resources and starve out the other species. If horse and moose are both grass eaters and horse are better at surviving against predators, then moose would be at risk of being crowded out by horses. At some point, the two species do need to be “equally survivable” in order to both continue to exist.
But, even if we assume that the horse strategy is massively better against predators than the moose strategy for dealing with predators, that doesn’t mean that horses are more survivable. There’s more to living in the world than bears.
Moose might have a greater option of terrain, for example. While the horses might deplete the open grass fields of food, the moose are able to get up into the rocky hills and survive.
More likely, moose probably require less energy to operate and die less easily. A horse runs away from a bear, tires out somewhere, collapses, and is eaten by cougars. It over-exhausted itself. Or horse runs away from bear, puts its hoof down on a rock at the wrong angle, trips, somersaults, breaks a leg or two, and on come the cougars. The horse has successfully avoided being predated, but landed into smaller scavenger territory.
There’s some equalizer between the species, whether its habitat or other factors. I’m not a sufficient expert on these animals in the wild in the territory and time period of which you’re thinking, but the fact that they both continued to breed generation after generation tells us that it’s so.