I'm not sure what niche you are asking about. The horse and donkey are genetically cousins. When you crossbreed these two cousins you get a mule. You never have to worry about breeding a mule though, they are born sterile. (unable to reproduce)
Equus, horses and donkeys.
yes
Yes, donkeys often graze with horses.
Donkeys and horses are not from the same species because of this: In sexual organisms, two organisms belong to the same species if they are able to breed and have fertile offspring. Although horses and donkeys can have mules, they are infertile, so they are two separate species and the mule is a hybrid.
Yes they are Same with asses, mules, donkeys, zebras
donkeys
Equidae, which includes horses and donkeys.
No
Donkeys are like horses in some ways.
that they sure do love to smash on a female dunkey
Horses have 64 chromosomes while donkeys have 62, thus a horse has two more chromosomes than a donkey. (For the record a mule has 63 a mix of the horses and donkeys numbers.)
Donkeys are in the horse family so... yes.