While this process occurred, three Asian styles may have influenced North American music across the Bering Strait, all featuring pulsating vocal technique and possibly evident in recent Paleo-Siberian tribes such as Chuckchee, Yukaghir, Koryak. Also, these may have influenced the Plains-Pueblo, Athabascan, and Inuit-Northwest Coast areas. According to Nettl, the boundary between these southward and the above northward influences are the areas of greatest musical complexity: the Northwest Coast, Pueblo music, and Navajo music. Evidence of influences between the Northwest Coast and Mexico are indicated, for example, by bird-shaped whistles. The Plains-Pueblo area has influenced and continues to influence the surrounding cultures, with contemporary musicians of all tribes learning Plains-Pueblo-influenced pantribal genres such as Peyote songs.