Yes.
A species.
Yes
They produce offspring so that organisms species doesn't become extinct!
Eye ring birds are able to interbreed and have fertile eggs, the offspring will be fertile as well. It is Not recomended though for peach face and eyerings to breed, that is where issues will start.
It is possible because they are the exact same species, Canis lupus familiaris.
A group of organisms that can mate and produce offspring which can themselves mate is called a species.
once they can no longer breed and produce a fertile offspring with the other group they become a separate species
It is where two ducks of the same species breed and produce hybrid offspring. Commonly in ducks, hybrids are most likely fertile.
labradors
Labradors are great with families.
All dog's are wolf related, they are all a sub species of the wolf. A dog can breed with a wolf and produce fertile offspring. If a dog cannot breed with a wolf then it is not a dog but another canine.
they can inter breed and produce fertile offspring.