The difference between eating turkey and eating bison (beefalo) is that beheimos and chayos have explicit simanim clearly enunciated in the Torah. The Torah does not specify simanim of kosher ofos. the simanim for birds are from divrei sofrim. A better question would be is a bison/beefalo a beheima or a chayah requiring kisui.
I have seen bison meat with chashuva hechseirim. Bison is very lean and one must be careful not to overcook it. An overcooked bison burger very closely resembles a hockey puck both in appearance and texture.