* Behavioural traits are easy to determine, as [[Reproductive_Behaviour_-_Copulatory_Behaviour_-_Anatomy_%26_Physiology#Mounting|mounting behaviour]] and [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_-_Anatomy_%26_Physiology#Erection|erection]] can be easily observed. | * Behavioural traits are easy to determine, as [[Reproductive_Behaviour_-_Copulatory_Behaviour_-_Anatomy_%26_Physiology#Mounting|mounting behaviour]] and [[Reproductive_Behaviour_-_Pre-copulatory_Behaviour_-_Anatomy_%26_Physiology#Erection|erection]] can be easily observed. |