Seasonal variation of LH and testosterone in the smallest deer, the pudu (Pudu puda molina) and its relationship to the antler cycle.

1. In order to obtain a seasonal profile of LH, three adult male pudu (Pudu puda, Molina) were sampled monthly from the saphenous vein for a period of one year. 2. A significant circannual variation of plasma LH levels was detected with an average peak value (1.77 ng/ml) recorded in February and nadir concentrations (0.19 ng/ml) observed in November. 3. The peak level of testosterone (1.54 ng/ml) was detected in March, the time of the rut.