 The heat is usually referred to as increased serum progesterone levels in the female fallow deer and is associated with the corpora lutea.The male rut behaviour includes licking and sniffing the anal area of the female, also the hair below the vulva, this helps the male to determine if the female is fertile.A high-pitched whine is used many times to initiate mating behaviour, after the male displays this a number of times the female will eventually allow the male to mount; copulation can last as long a 5 minutes.