Maine Department of Inland Fisheries and Wildlife Wildlife Technician, Carter Barthelman, calls for moose. During the moose breeding season-the rut. Moose hunters try to imitate the call of a cow in estrus. This call is a long, plaintive moaning. This is telling a bull that she is receptive and ready to breed. If a bull responds to the cow, the bull will make a deep, guttural grunt expelling air. He will make the call repeatingly as he moves towards the cow call and tries to scent the female.