Billies have a large, stocky shape and weigh an average of 200 pounds, and have a gradual curving horns. The diameter of the horn base is large which makes for a narrow space between the horns. A distinct feature of billies is the style of stretching to urinate, as opposed to females whom squat. Nannies are smaller in size and weigh approximately 160 pounds. The horns of a nanny are slender and curve sharply near the tip.
Nannies exhibit a small horn base with wide spacing between the horns.
Billy goats have a large horn base with a narrow space between the horns. Nanny goats have slender shaped horns with a sharp curve near the tip of the horn. Billy goats feature a stained rump and will urinate by stretching forward. Learn more about mountain goats from the Alaska Wildlife Notebook Series . All Rights Reserved.