The red flap of skin on turkey's neck is called the wattle. The wattle is typically light red, but it changes color as the turkey's mood alters.
When a turkey becomes angry, upset or excited, the wattle darkens and takes on a bright red hue. The wattle also changes to a red color to alert females that the male turkey is looking for mate. When the wattle lightens greatly, or takes on a bluish tint, it is an indicator that the turkey is ill or is in an uncomfortable situation. The wattle is not the only part of the turkey that changes color, as when the turkey is ready to mate, their entire head will darken and take on more of a red coloring.