Cats especially are very careful where they shit and often bury it. Felines in general, but perhaps less-so.
Canines are even less careful but make a token effort, and as the saying goes, “Does a bear shit in the woods?”
Cows, goats, and sheep on the other hand are not noted for anal management - though I have seen escaping herbivores spraying vigourously from the tail gun.
Perhaps because they are territorial and while #1 marks their territory, #2 might give away way too much information such as what they ate etc? Just guessin.
Hippos and rhinos , though they are herbivores, as mean as they are, might want to let others know of their presence as have you ever seen them spraying wet crap with their tail?
It seems dangerous herbivores that can fend themselves seem to advertise their presence rather than not caring. Just trying to layout different observations…
First, carnivores stalking their prey want to be as unnoticed as possible; this requires a certain amount of bladder and sphincter control. Most animals, unlike us, are very sensitive to smell.
Secondly, the animals with pretty good control tend to be lair animals; they establish a lair or hideout at least to raise young, and also often to live in, for shelter. Thus herbivores with a home have a bit of common sense not to shit where they sleep; although herbivores are less discriminating about cleanliness once away from home, much like men in public toilets.
Also, as mentioned above, animals use #1 or #2 to mark their territory. Dogs, among others, have a gland that adds a small sample of their scent to feces on its way out. Like Paris Hilton and other perfume-peddling celebrities, each dog turd has a personal scent that marks its owner. Hence the “dog sniffing ass” meme - “getting to know you, …”
Herd animals wandering a vast expanse with no fixed point to return to are especially happy to let fly wherever they happen to be. There is nothing special about any place, and odds are only random meandering will bring them back there before weather and dung beetles have dealt with their mess. There is no evolutionary advantage to hiding or burying number 2. In fact, having a toilet equivalent of the elephant’s graveyard would be an evolutionary disadvantage. There should not be a particular one spot where predators can catch them with their pants down, so to speak.
I am not sure if cows or horses, for example, are conditioned not to let fly in watering holes - but that would be the only place where evolution would suggest they learn to hold it.
It is also worth noting that herbivores tend to defecate a lot. Due to the intake of non-digestable material, they produce copious amounts of waste compared to pure carnivores, and even considerably more than primarily fruit-and-nut eating omnivores like bears or apes. A cow could spend all day trying to bury its waste and would just end up stuck in a big hole full of shit.
Another random biological WAG here – carnivores make little poo, meat is concentrated energy, with little roughage. Obligate carnivores, like cats, eat little, and poop little. They can have the luxury of careful poo covering. Also, they’re small solitary animals, they’re tasty prey themselves. Dogs, like wolves, can and do supplement their diet with plant material, and they have a different social culture as well to defend the group, and they’re bigger – so they keep a half assed (heh) cleanup instinct.
Herbivores eat large amounts, pooping almost constantly. Sure, they might benefit from hiding their excreta, but it would take too much time, and chop up the grassland to the point that no more grass would grow.
This burying of waste is, according to some forgotten Nova special I saw, why humans keep carnivores as pets. They can be trained to poo at a certain time and place, we just manipulate their poo-burying instinct. No matter how small we breed a horse, and how concentrated we make it’s feed, its still a challenge to keep it indoors. Yeah, I know some people keep the tiny ones around – but that’s their challenge, not mine.
Could just be what you get used to, but cow crap doesn’t make me retch when I smell it, even when I’m in a particularly nasty barn. Doggy doo on the other hand offends me at the slightest whiff.
Oh, I don’t mind the smell (especially since it evokes pleasant memories of rural areas). I’m just saying that the smell is quite strong. Although to be fair, when one encounters cow manure, it tends to be in much larger quantities than dog.