Re: Get with the program!
A "Liger" is a cross between a Lion and Tiger, right? Which would show that they're pretty closely related, enough to cross-breed viably (sorry I don't know whether their offspring can continue breeding or are sterile).
So that would suggest pretty much same species (maybe depending on how you define "species").
a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g. Homo sapiens.
Tigers and lions may be able to breed, but like horses and donkeys, the offspring are infertile. As such, they cannot successfully interbreed, which is one reason they're classified as different species.