In males, tubercles occur from mid-May to early August with peak development going from June to July, at the same time as other indicators of reproductive condition. In males, epidermal thickness is significantly higher between mid July and early August, but it stays constant in females.
During the summer months, males exhibit tubercle growth from May to August, peaking in June and July, which is also reflected in other signs of reproductive readiness. Meanwhile, female epidermal thickness remains unchanged throughout this time frame.