If it's just an artificial category, then members of different species should be able to successfully mate and reproduce, thus creating a new species. Oh, wait, that can't happen, scientifically.
Huh? Where did you get this remarkable deduction?
There are creationists right here on FR who appear to think lions and tigers are the same species, for example, because they can mate and produce viable offspring.
But, for example, blue winged and golden winged warblers, which have always been classed as different species, mate and produce viable fertile offspring which are quite different from either parent. The hybrids, in fact, were once classified as a third species, and in mating with each other, produce F2 hybrids which were classified once as a fourth species. So, in fact, your attempt at a reductio ad absurdam, while logically flawed, isn't even absurd!
BTW, you didn't answer the oriole challenge.