Archive for November 30th, 2015

November 30, 2015

Dewlap

anole

turkey

A dewlap [doo-lap] is a longitudinal flap of skin that hangs beneath the lower jaw or neck of many vertebrates. While the term is usually used in this specific context, it can also be used to include other structures occurring in the same body area with a similar aspect, such as those caused by a double chin or the submandibular vocal sac of a frog. In a more general manner, the term refers to any pendulous mass of skin, such as a fold of loose skin on an elderly person’s neck, or the wattle of a bird, a drooping protuberance hanging from various parts of the head or neck.

Many reptiles have dewlaps, most notably the anole species of lizard, which have large skin dewlaps which they can extend and retract. These dewlaps are usually of a different color from the rest of their body and when enlarged make the lizard seem much larger. They display them when indicating territorial boundaries and to attract females. Lizards usually accompany their dewlap movement with head bobs and other displays. Though much uncertainty resides around the purpose of these displays, the color of the dewlap and the head bobs are thought to be a means of contrasting background noise.

read more »