It's Turkey (Science) Time!
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A wild turkey strutting his stuff. Image by Frank Schulenburg.
Thanksgiving might look a little different for Americans this year, but it’s safe to assume that turkey will still end up on many of our plates this season. Maybe your family has a special way to serve turkey, and spent years perfecting the perfect recipe. Or maybe you’ve spent time debating whether the tryptophan in turkey is the reason why you get so sleepy after a hearty Thanksgiving meal (hint: it’s complicated!). Whatever your traditions are, this could be the year that you impress friends and relatives with your knowledge of the biology and natural history of the turkey, whether at the dinner table, over video chat, or by writing a long letter by the light of a flickering candle.
From Forest to Table: The Origin of Turkeys
So, what makes a turkey a turkey? The first thing to understand is that turkeys are not just oversized chickens. Chickens originated in Asia, while turkeys are native to the Americas. Turkeys and chickens are both members of the order Galliformes, but they are separated by tens of millions of years of evolution. The closest relatives of turkeys are grouses, and pheasants are another close cousin. Chickens are more closely related to peafowl, and certain species of partridges.
Current evidence points towards turkeys being domesticated over 2,300 years ago in Central America. Though they were still genetically similar to wild turkeys, several aspects of their lifestyle suggested at least partial domestication. They both lived and reproduced alongside humans, and their flight muscles were reduced compared to a wild turkey. Further research will certainly refine the domestication timeline of turkeys further, but we can certainly say they’ve been with us for some time.
Ancient humans brought some domesticated animals, like dogs, with them when they migrated to America, but turkeys were the first vertebrate domesticated on the American continents. Turkeys have many natural qualities that made them good candidates for domestication. Even wild turkeys have very large bodies with plenty of meat, and domestication only increased their body mass. They prefer to live in groups, and their omnivorous diet includes the sorts of insect pests that might be found in the extensive corn fields cultivated by early Americans.
Chalchiuhtotolin could transform into a turkey to menace villages with death and disease.
Turkeys were raised by the Mayan and Aztec empires, but it is unlikely that they were a common food source. They may have been used for ceremonial offerings (in Aztec mythology, the turkey god Chalchiuhtotolin presided over disease and plague!), or as a food for the wealthy upper class.
A second turkey domestication event occurred in what is now the southwestern United States, by the Anasazi people. However, the turkeys we have today originated from the Mesoamerican turkeys, and the line of turkeys from this second domestication event seems to have died out.
When the Europeans arrived in the New World, they quickly developed a taste for turkeys. They brought turkeys back to Spain, and turkey farms began to spread across Europe. Their popularity surged, first among the upper classes, hungry for exotic new meats, and later among the general population. Now, turkeys have achieved a global reach, and are taking further root in developing economies across the world.
Wild vs Domesticated
After thousands of years of selective breeding, domesticated turkeys have a number of differences from their wild cousins. Some of these differences lie in their genes. Domesticated turkeys have much less genetic variety than wild turkeys. Even when compared to other domesticated animals, variability in turkeys is low. The genes most affected by the shift to domestication are those related to breast muscle development and body size.
There are many distinct physical differences between wild and domesticated turkeys as well. One obvious change is in color. While wild turkeys have black and brown feathers, which serve as camouflage in their natural environment, the turkey breeds most common in commercial farming are white. When turkeys are plucked, if the remaining pin feathers are white, they are less visible against the turkey’s pale skin. This tends to be more attractive to consumers, and so white turkeys dominate the industry.
Image by Andy Reago & Chrissy McClarren.
When you think of a turkey, do you imagine a large and ungainly bird waddling about? That might be said about domesticated turkeys, with their short legs and huge breasts, but wild turkeys are swift and lean, with long muscular legs. Domesticated turkeys are unable to fly with their oversized breast muscles, but wild turkeys can burst into the air at speeds of up to 55 miles per hour, and can fly for up to a mile at a time.
Turkeys are often ridiculed for their lack of intelligence, but wild turkeys are anything but stupid. Hunters consider turkeys one of the most crafty and hard to capture game species. They are notoriously wary, and can evade all but the most patient. Of course, wild turkeys in the suburbs often become much bolder than those that live in the forest.
So, which make for better eating? It depends on what you’re looking for. The meat on wild turkeys is darker and leaner, with rich intense flavors. However, if you like drumsticks, you should definitely stick to the domesticated version. Wild turkey legs are very tough, and full of bony tendons.
If you want to try a different sort of turkey, another option would be to seek out a heritage breed. There are over ten different heritage turkey breeds recognized, and they are often raised on smaller farms than the big commercial breeds. Or maybe you might want to go in another direction entirely this Thanksgiving, and try pumpkin lasagna instead!
An ocellated turkey. Photo by Rbreidbrown.
Other cool turkey facts guaranteed to impress:
- Only male turkeys “gobble.” They make this sound in attempt to attract females during mating season.
- A turkey’s featherless head is normally red, but depending on a turkey’s mood, can change color to blue, white, or some combination of the three.
- Turkeys were named after the country Turkey, by Europeans who thought the birds looked like African guineafowl, which at the time were associated with Turkey (the country).
- Sometimes, turkey eggs will begin to develop without fertilization. This is called parthenogenesis. It is rare that these eggs survive long enough to hatch.
- There are only two surviving species of wild turkey. The less common of these is the ocellated turkey, which only lives on the Yucatan Peninsula, and has a glorious rainbow of feather colors.
- Kate Dzikiewicz, Science Curatorial Associate and Seaside Center Manager
