Tigers to identify his territory, the male marks trees by spraying of urine and anal gland secretions, as well as marking trails with scat. Males show what is called called the Flehmen response. In the Flehmen response, animals draw back their lips in a manner that makes them appear to be “grimacing”. The action, which is adopted when examining scents left by other animals either of the same species or of prey, helps expose the vomeronasal organ and draws scent molecules back toward it. This behavior allows animals to detect scents, for example from urine, of other members of their species or clues to the presence of prey. Flehming allows the animals to determine several factors, including the presence or absence of estrus, the physiological state of the animal, and how long ago the animal passed by. Read more in the embedded book Amur Tiger