What’s the Purpose of a Turkey’s Wattle?

A turkey’s fan of feathers can make it look like quite a regal beast—a stark contrast to the pimply mess of flesh on and around its head. Though repulsive to humans, the facial baggage on male turkeys (toms) can actually be alluring to their female counterparts (hens).

According to some studies, the part atop a turkey’s beak, called a snood, helps hens determine which toms to mate with. The longer the snood, the better the genes. Wattles, which hang below turkeys’ beaks, also come into play during the mating process. As explained on the audio program BirdNote, blood flows into the wattle of a tom trying to attract a mate, which turns the wattle a much brighter red than normal. This helps them stand out from other toms strutting around with long snoods and splayed feathers.

Just as blood rushing to the wattle can indicate arousal, blood rushing away from the wattle can indicate the opposite. If a turkey spots a predator nearby, fear can cause blood to drain from the wattle, which temporarily turns blue. A pale snood and/or wattle can also be a sign that the turkey is suffering from anemia or another illness.

Wattles—on both toms and hens—aren’t just visible symbols of turkeys’ physical and mental states. Since birds don’t have sweat glands, they rely on other methods to keep them cool. Some, like toucans, have especially large bills that can release excess heat. Blue herons, on the other hand, unfurl their wings to circulate more air. For turkeys, the built-in mechanism for unloading heat is the exposed skin of the wattle (and neck in general). This helps offset their dark, heavy plumage.

[h/t BirdNote]

A version of this story was published in 2020; it has been updated for 2023.