Turkeys have wattles primarily to attract mates, signal dominance, and regulate body temperature. That fleshy flap of skin dangling beneath a turkey’s chin serves multiple overlapping purposes, from broadcasting a male’s fitness to rival toms and potential mates, to dumping excess body heat on a warm day. It’s one of several fleshy head ornaments that make turkeys one of the most visually distinctive birds in North America.
What a Wattle Actually Is
The wattle (sometimes called a dewlap) is the fleshy, hanging appendage under a turkey’s chin and neck. It’s made of bundles of collagen fibers enriched with a dense network of blood vessels. There’s no bone or cartilage inside, just connective tissue and vasculature wrapped in skin.
Turkeys also have two other fleshy structures that people sometimes confuse with the wattle. The snood is the long, finger-like protrusion that drapes over the beak. Caruncles are the bumpy, textured growths covering the head and upper neck. All three structures can change color and size depending on the bird’s mood, but each plays a slightly different role.
Sexual Selection and Mate Choice
The wattle’s most important job is advertising a male turkey’s quality to females. Larger wattles signal a more dominant tom. During mating season, hens evaluate males using a combination of visual cues, and wattle size is part of that package alongside snood length and caruncle prominence. Snood length, in particular, has been shown to be a trait that hens actively select for when choosing a mate, and the overall display of engorged, colorful fleshy ornaments plays into that decision.
Caruncle size correlates with testosterone levels, and wattle size tracks with social dominance rank within a flock. Males with bigger, more impressive head ornaments tend to win mating opportunities more often, which means these traits get passed on generation after generation. This is classic sexual selection: females choosing mates based on traits that honestly signal health and genetic fitness, because maintaining large, well-vascularized fleshy structures takes energy and good nutrition.
Establishing Dominance
Wattles aren’t just for impressing hens. Male turkeys use them in competitions with other males. During aggressive encounters, toms can engorge their wattles with blood, making them swell and change color as part of an intimidation display. This wattle engorgement is one of several behavioral signals used to establish pecking order, alongside tail spreading, wing flapping, and strutting.
Status in the male hierarchy is related to size, coloration, and display characteristics. A tom that can puff up a large, brightly colored wattle is communicating physical condition and testosterone levels without needing to fight. These displays help resolve conflicts before they turn physical, which benefits both birds by reducing the risk of injury.
How Wattles Change Color
One of the wattle’s most striking features is its ability to shift between red, white, and blue in a matter of seconds. The mechanism behind this is surprisingly elegant.
When a turkey is calm, the collagen bundles inside the wattle stay small and relatively transparent. Blood vessels show clearly through the skin, giving the wattle its familiar bright red appearance. But when the bird becomes excited, agitated, or aroused, those collagen bundles expand and become opaque. They scatter light instead of letting it pass through, which obscures the blood vessels underneath. The result is a wattle that shifts from red to white or even blue, depending on how much the collagen has expanded. During mating season, the snood, caruncles, and wattle together function almost like mood rings, expressing confidence, aggression, calmness, or submission depending on the situation.
Thermoregulation
Beyond social signaling, wattles serve a practical physiological function: they help turkeys shed excess body heat. Birds can’t sweat, so they rely on other mechanisms to cool down, including panting (evaporative cooling through the respiratory tract), radiating heat from exposed skin, and losing heat through convection when air moves over bare surfaces.
The wattle’s rich blood supply makes it an efficient radiator. Blood flowing through the wattle’s extensive vascular network releases heat to the surrounding air, especially when there’s a breeze. Research on commercial turkeys has confirmed that wattle temperature responds to environmental conditions, including air temperature, humidity, and wind speed. Forced ventilation in turkey barns effectively lowers wattle temperature, which is why wattle temperature is now used as an indicator of thermal comfort in poultry management. In younger turkeys (around two months old), humidity also plays a significant role in wattle temperature, while older birds rely more on air temperature and wind speed for heat dissipation.
This cooling function helps explain why the wattle evolved to be featherless. Feathers are excellent insulation, which is exactly the opposite of what you want on a structure designed to dump heat.
Wattles as Health Indicators
Because wattles are so vascular and visible, they also serve as a convenient window into a turkey’s overall health. A healthy turkey’s wattle is plump, well-colored, and smooth. Changes in wattle appearance can flag a range of problems.
- Pale or shrunken wattles often indicate anemia, which can result from parasitic infections, nutritional deficiencies, or diseases like fowl typhoid. In severe cases, fowl typhoid causes progressive wasting with intensely pale, shrunken wattles and can kill more than half a flock.
- Swollen wattles are a hallmark of fowl cholera, a bacterial infection. Chronic cases produce visible abscesses in the wattle tissue.
- Wart-like lesions on the wattle suggest fowl pox, a viral disease that produces yellow to dark brown nodular growths on the head, comb, and wattle.
- Dark red or purplish wattles can signal poor circulation, respiratory distress, or cardiovascular problems resulting in low blood oxygen levels.
For backyard flock owners, checking wattle color and texture is one of the quickest ways to spot that something is off with a bird’s health before other symptoms become obvious.
Why Males Have Bigger Wattles
Both male and female turkeys have wattles, but males typically sport larger, more brightly colored ones. This dimorphism is driven by sexual selection. In the pheasant family (which includes turkeys, chickens, and peafowl), fleshy ornaments on the head and neck evolved first as basic features in both sexes, then were amplified in males through generations of female mate choice and male competition. The result is that toms display large, dramatic wattles during courtship while hens carry more modest versions that still function for thermoregulation but aren’t under the same selective pressure to be visually impressive.
This pattern holds across the pheasant family. Roosters have their combs and wattles, male jungle fowl display swollen red facial skin, and male turkeys have the full suite of snood, wattle, and caruncles. In each case, females of the same species have smaller, less conspicuous versions of the same structures.