<br> The official bird of Thanksgiving is chock full of surprises. For example, one of our founding fathers strongly recommended that the <a href="http://www.livescience.com/9094-avoiding-fried-turkey-disaster.html">turkey</a> replace the eagle as our national bird. Read on for more fun, fascinating turkey facts.
<br> Because turkeys are so large and heavy — with the heftiest wild turkey weighing 37 pounds (17 kilograms), according to the National Wild Turkey Federation — it's often assumed that these big birds stick to the ground. In fact, turkeys prefer to sleep perched atop tree branches, where they are safe from <a href="http://www.livescience.com/6892-turkey-hunters-hunted.html">predators</a>, which include coyotes, foxes and raccoons. They often sleep in flocks, and upon waking, call out a series of soft yelps before descending to make sure that the rest of their roosting group is okay after a night of not seeing or hearing one another.
<br> Don't be disappointed if the turkey at the petting zoo refuses to gobble — it's probably a female, which is called a hen. Male turkeys are called gobblers, because they are the only ones that can make that adorable gobbling sound. Each male turkey has his own unique gobbling "technique," which he combines with <a href="http://www.livescience.com/10216-turkey-runs-winged-dinosaurs-scientists.html">strutting to attract potential mates</a>. Female turkeys communicate through clucks and small, chirp-like noises.
<br> If you feel groggy after an old-fashioned Thanksgiving meal, the bird on your plate may be partially to blame. Turkey meat contains tryptophan, an amino acid that the body uses to make serotonin, a neurotransmitter in the brain that helps regulate sleep. However, <a href="http://www.livescience.com/4723-thankgiving-myth-turkey-sleepy.html">all meat contains tryptophan</a> at comparable levels. Other tryptophan-rich foods include cheese, nuts and shellfish. <br> <br> What makes the Thanksgiving meal so memorably tiring is the mix of meat with carbohydrates. Carbs from stuffing, sweet potatoes, bread, pie and sugary sweets stimulate the release of insulin, which then triggers the uptake of most amino acids — except for tryptophan — from the blood into the muscles. With the other amino acids swept out of the bloodstream, tryptophan doesn't have to compete with them and is better able to make its way to the brain to help produce serotonin, which then preps you for sleep.
<br> Apparently, <a href="http://www.livescience.com/549-ben-franklin-quirkiest-ideas.html">Benjamin Franklin</a> was a big fan of the humble gobbling bird. According to the Franklin Institute, he wrote in a letter to his daughter: <br> <br> "For my own part, I wish the bald eagle had not been chosen as the representative of our country; he is a bird of bad moral character; he does not get his living honestly...like those among men who live by sharping and robbing...he is generally poor, and often very lousy. Besides, he is a rank coward; the little king-bird, not bigger than a sparrow, attacks him boldly and drives him out of the district...For in truth, the turkey is in comparison a much more respectable bird, and withal a true original native of America. Eagles have been found in all countries, but the turkey was peculiar to ours..."
<br> Wild turkeys can fly for short bursts at speeds of up to 55 miles per hour (89 kilometers per hour). However, they aren't often spotted soaring through the sky because they prefer to feed on the ground, where they peck at grass, seeds, acorns, nuts, berries and small insects such as grasshoppers. <br> <br> The myth of turkeys' inability to fly may stem from the fact that many domestic turkeys, such as the broad-breasted white turkey — which is the most widely used breed commercially — cannot fly; they are too weighed down by their own meat. These <a href="http://www.livescience.com/3080-science-build-turkey.html">birds have been selectively bred</a> to be much heavier and possess a larger, broader breast, the weight of which keeps them perpetually grounded.
<br> As many hunters know, a turkey has <a href="http://www.livescience.com/8099-chickens-color-humans.html">excellent vision</a>. Because its eyes are on the sides of its head, the turkey has periscopic vision, which allows it to see objects that are not in its direct line of vision. By rotating its head, the turkey has a 360-degree field of vision, according to James G. Dickson's "The Wild Turkey: Biology and Management" (Stackpole Books, 1992).
<br> When a turkey becomes frightened, agitated, excited or ill, the exposed skin on its head and neck can change from its usual pale pink or bluish gray color to red, white, or blue. And during mating season, the male turkey's wattle turns scarlet to reflect his elevated sex hormone levels. The fleshy flap of skin that hangs over the gobbler's beak is called a snood and also turns bright red when the bird is excited.
<br> Here's one part of the turkey that the kids definitely won't be fighting over at the Thanksgiving table: A part of the bird's stomach, called the gizzard, contains tiny stones that the bird has previously swallowed. Also known as gastroliths, these polished stones aid in the breakdown of food for digestion, since birds do not have teeth.</p> <br> They do, however, have two stomachs, the first of which is called the glandular stomach, where food is softened and broken down by <a href="http://www.livescience.com/515-bacteria-thrive-hostile-human-bellies.html">gastric juices</a>. The food then enters the turkey's gizzard, which is extremely muscular and further dissolves the food by grinding it against the gastroliths before moving the mulch along into the intestines or back into the glandular stomach for a more thorough digestion.