interbreed

To breed or reproduce within an isolated community.

To breed or reproduce within a heterogenous community, the products of which produce hybrids.

The rypes and our red grouse are identically the same bird, though disease has never been known in the former, and even interbreeding with the red grouse, to the limited extent they are ever likely to do, should do more good than harm.

The city's two-inch Environmental Review Technical Manual instructs regulators to consider adverse environmental impacts on "any subspecies" or "any distinct population segment . . . which interbreeds when mature."