But Charles Darwin already gave the scientific answer to this and all related questions back in 1859:
I look at the term species as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other.Ever since then taxonomists have been trying to somehow save the concept of species from Darwin's Nominalism, but none of their definitions really stands up.
So far as I can see, biology has pretty much nothing to say about whether or not red wolves are a species. There is some evidence one might consider, such as that red wolves would rather breed with other red wolves than with coyotes, but nothing truly definitive. In terms of the Endangered Species Act, the question is a political one. Personally I like red wolves and would like them to stay around, but I wouldn't presume to say this is based on really good science.
It still mystifies me that so many biologists and paleontologists remain obsessed with defining species, given that they all believe in evolution, which teaches that in the long run there is really no such thing.