Do birds ever mate between species?
Yes, but not in the case of a Blue Jay and Cardinal. Blue Jays and Cardinals are not even closely related (besides the fact that they are both birds), and are both in a different families and genus. Some very closely related birds that are both in the same family and genus CAN produce hybrids. There are records or two different types of hummingbirds in the same genera that can reproduce with each other. The same goes for some species of warblers, Townsend’s and Hermit Warblers have been known to produce hybrids..but once again..they are closely related. A Japanese person and a Caucasian person are both still the same species (Homo sapien or Human). Being a different race does not make you a different species.
