The tiger has a muscular body with powerful forelimbs, a large head and a tail that is about half the length of its body. Its pelage is dense and heavy, and colouration varies between shades of orange and brown with white ventral areas and distinctive vertical black stripes that are unique in each individual. Stripes are likely advantageous for camouflage in vegetation such as long grass with strong vertical patterns of light and shade. The tiger is one of only a few striped cat species; it is not known why spotted patterns and rosettes are the more common camouflage pattern among felids. A tiger's coat pattern is still visible when it is shaved. This is not due to skin pigmentation, but to the stubble and hair follicles embedded in the skin, similar to human beards (colloquially five o'clock shadow), and is in common with other big cats. They have a mane-like heavy growth of fur around the neck and jaws and long whiskers, especially in males. The pupils are circular with yellow irises. The small, rounded ears have a prominent white spot on the back, surrounded by black. These spots are thought to play an important role in intraspecific communication.