I Didn’t Know That...

Q. Why do turkeys have white meat and dark meat? They are both muscle, aren’t they?

A. Birds have two types of muscle fibers, called red and white muscles, according to animal scientist Ralph Ernst of UC Davis. The red muscles have much greater endurance and are used for activities that involve sustained motions, such as walking and migratory flights. The white muscles are designed for short bursts of activity. The so-called upland game birds, such as quail, pheasant and wild turkey, have wings controlled by white muscles in the breast. They do not migrate, and they fly mainly short distances-- up to 500 yards or so-- to evade predators. Migratory birds, such as geese, have red muscles in their breasts.

The red muscles have larger amounts of myoglobin, a hemoglobin-like molecule that transports and stores oxygen within the muscle and imparts the red color. They also have more mitochondria, which provide energy, more blood vessels, and a higher content of fats.