Ayaapeensa Kiilhswa ‘Young Buck Moon’ (listen to the pronunciation on the Myaamia Online Dictionary) is one of two lunar months named for moohswa ‘White-tailed deer (Odocoileus virginianus).’ To the best of our knowledge, this month is associated with the beginning of the rut (breeding cycle) for moohswa.
In some years, the younger males lose their antlers by the end of this month. Today, there is a lot of variation within the moohswa populations regarding when bucks drop their antlers. It appears that historically, the young bucks dropped their antlers first. The loss of antlers marks the end of the rut for these younger males.
You can learn more about White-tailed deer by visiting Wikipedia.