What is the requirement for a male bighorn sheep to be deemed harvestable?

A male bighorn sheep is considered harvestable when one or both antler tips exhibit a completeness of at least a half circle. This guideline is set to ensure that only mature males are harvested, which generally contributes to maintaining a healthy population. The requirement focuses on assessing the development of the animal, as younger males may have incomplete antler growth, while mature males typically demonstrate more robust and symmetrical antler characteristics.

The criteria in other options either emphasize measurements that do not adequately represent maturity in relation to antler development or are unrealistic for assessing harvest eligibility. Thus, the requirement for antler tips to be complete at least a half circle provides a clear and effective standard for hunters to follow, ensuring the continuation of viable bighorn sheep populations.