called floaters, switch between territoriality and nomadism depending on the availability of females. A 1987 study showed territoriality depended on the size and age of males and the membership of the coalition. The ranges of floaters averaged in the Serengeti to in central Namibia. In the Kruger National Park (South Africa) territories were much smaller. A coalition of three males occupied a territory measuring , and the territory of a solitary male measured . When a female enters a territory, the males will surround her; if she tries to escape, the males will bite or snap at her. Generally, the female can not escape on her own; the males themselves leave after they lose interest in her. They may smell the spot she was sitting or lying on to determine if she was in oestrus. Communication The cheetah is a vocal felid with a broad repertoire of calls and sounds; the acoustic features and the use of many of these have been studied in detail. The vocal characteristics, such as the way they are produced, are often different from those of other cats. For instance, a study showed that exhalation is louder than inhalation in cheetahs, while no such distinction was observed in the domestic cat. Listed below are some commonly recorded vocalisations observed in cheetahs: Chirping: A chirp (or a "stutter-bark") is an intense bird-like call and lasts less than a second. Cheetahs chirp when they are excited, for instance, when gathered around a kill. Other uses include summoning concealed or lost cubs by the mother, or as a greeting or courtship between adults. The cheetah's chirp is similar to the soft roar of the lion, and its churr as the latter's loud roar. A similar but louder call ('yelp') can be heard from up to away; this call is typically used by mothers to locate lost cubs, or by cubs to find their mothers and siblings. Churring (or churtling): A churr is a shrill, staccato call that can last up to two seconds. Churring and chirping have been noted for their similarity to the soft and loud roars of the lion. It is produced in similar context as chirping, but a study of feeding cheetahs found chirping to be much more common. Purring: Similar to purring in domestic cats but much louder, it is produced when the cheetah is content, and as a form of greeting or when