Female effect on antlers of pampas deer (Ozotoceros bezoarticus)

Size and bone mineralization of deer antlers are related to testosterone concentrations, and antler cast is observed after withdrawal of testosterone concentration. Our objectives were to determine if (i) contact with hinds stimulates antler development and increases hard antler period length in pampas deer ( Ozotoceros bezoarticus (L., 1758)) and (ii) antlers from males that were or were not in contact with hinds differ in colour. While 5 males were in breeding paddocks consisting of 1 adult stag and 5–10 hinds, the other 6 males were allocated as a single-male group. We collected, weighed, and measured the volume, circumferences, and lengths of antlers, and determined their colour. First antler cast tended to be later in males in contact with females than those in the single-male group. Antler mass and volume were greater in antlers from males in contact with females. Circumference at the base of first and second tines was also greater in antlers collected from males in contact with females. Surfaces of antlers from these males were darker than those of antlers from males that remained isolated from females in all points. Hind contact stimulated male pampas deer, increasing antler mass, size, and darkness, as well as possibly hard antler period length.