[throwaway41968]

Absolutely not. There's no clear, ambiguous definition of "species" that does not have counter-intuitive implications. No, the classic "fertile over two generation" thing you learn in high school doesn't cut it. Also, the commonly used criterion vary from which domain is being dealt with.

In practice, this means that two individuals are said to belong to a different (resp. identical) species if everyone in the community agrees that they do. That's what it means to be a "social construct", not that the differences per se aren't real.

Justifying other statements on the lines of "X is a social construct" similarly, where X ranges across a variety of more-or-less controversial concepts, is left as an exercise to the reader.