During the mating season, the face and genitalia of males redden and the tail stands erect. In addition, females' faces and anogenital regions turn scarlet. Macaques copulate both on the ground and in the trees, and roughly one in three copulations leads to ejaculation. Macaques signal when they are ready to mate by looking backward over a shoulder, staying still, or walking backwards towards their potential partner. A female emits a "squawk", "squeak", or produces an atonal "cackle" during copulation. Males have no copulatory vocalizations.