Caruncle (bird anatomy)

A caruncle is defined as 'a small, fleshy excrescence that is a normal part of an animal's anatomy'.

[6] Having large caruncles or colorful bright ones indicates high levels of testosterone, that they are well-fed birds able to elude other predators thus showing the good quality of their genes.

[7] It is believed that for birds living in tropical regions, the caruncles also play a role in thermoregulation, making the blood cool faster when flowing through them.

The wattle is a flap of skin hanging under the chin connecting the throat and head and the snood is a highly erectile appendage emanating from the forehead.

Usually they are pale, but when the male becomes excited or during courtship, the caruncles, wattle and snood all engorge with blood, become bright red or blue, and enlarge.