Until I acquired a parrot of my own, I was always a little intimidated by the pointed upper mandible, especially in the larger species. I had no idea that the tip of the upper mandible is the most sensitive part of the bird’s beak. He gauges the texture of whatever he’s exploring with the tip in order to decide how much pressure is required to crack a nut or to take a bite of soft fruit. The fixed upper mandible is “stuck” to the skull by a cartilage-like tissue. The edges of the upper beak are used for slicing. However, the upper beak is not dangerous since the bird uses it to hold onto objects. The lower mandible is the fearsome part! A parrot uses the scooped out, shovel-like lower mandible in a saw-like motion to tear apart whatever he’s eating or destroying.
The parrot bill is composed of keratin much like our nails. It is not solid. It has grooves inside to accommodate a large network of blood vessels and nerves. The visible part of the bill is simply a protective covering for the mouth. It grows about an inch or so a year in a healthy bird. In the wild, the parrot keeps it worn down by chewing. In captivity, the bill must be ground down to prevent overgrowth which happens if the parrot is not provided with a constant supply of toys and wood blocks on which to chew. The scaly appearance of the upper mandible is natural and is the bill’s method of shedding to replace old material with new. The “hinge” muscle that you see in this photo connects the upper and lower beaks and provides the crush strength for the bill.
A cere (resembling a human cuticle) runs across the top of the bill. This waxy area covers a space that opens directly to the bird’s brain. Damage to the cere can be fatal in parrots since bacteria could reach the brain and cause infection. The holes in the fleshy tissue on the cere are called nares. They are the bird’s “nose” leading directly to the respiratory system. Enlargement of the area of the cere around the nares often indicates a vitamin A deficiency.
The opening under the lower mandible appears to be designed to allow the parrot to bend his head forward to groom his belly and lower body. If the beak were straight across on the lower edge, the parrot would injure his throat by tilting his head downward. If a parrot allows you to scratch (“scritch” in parrot speak) the area under that opening, you have won his complete trust.
The tongue is the most intriguing part of the mouth. It is a very muscular and versatile tool. A parrot can manipulate anything that he can get into his mouth and eat it without dropping it simply by using his tongue. Watching a parrot use his tongue is fascinating.
Since parrots are so commonly kept as companions and since little is often known about parrot anatomy, I wanted to demonstrate with photos of Rita, how a parrot’s beak is constructed. The bill is interesting, but its use reaches far beyond the utilitarian tasks of foraging and eating. He uses his beak to preen himself and his mate….who just might be you…if you are lucky enough to be chosen as his special friend. 🙂
(click images to enlarge)