Before European settlers arrived in North America, there were millions of wild turkeys spread across what are now 39 U.S. states. But by the 1930s, wild turkeys had disappeared from at least 20 states and their total population had dropped to 30,000.

Over the next few decades, a series of reforms, conservation efforts and demographic changes helped bring wild turkeys back from the brink of extinctionmaking them one of the United States biggest wildlife success stories.

Wild turkey populations started declining in the 17th century as Euorpean colonists hunted them and displaced their habitats. By the time President Abraham Lincoln made Thanksgiving an official U.S. holiday in 1863, wild turkeys had disappeared completely from Connecticut, Vermont, New York and Massachusetts. Within a couple decades, they also disappeared from states farther west like Kansas, South Dakota, Ohio, Nebraska and Wisconsin. In an 1884 issue of Harpers Weekly, one writer predicted wild turkeys would soon become as extinct as the dodo.

Illustration for a 1908 Thanksgiving postcard.

Jim Heimann Collection/Getty Images

Wild turkeys, or Meleagris gallopavo, were not the only native U.S. species that were in danger. By 1889, there were only 541 American bison left. By the 1930s, when wild turkey populations hit their lowest, the passenger pigeon had already become extinct. The crisis in native species populations galvanized conservationists, who helped pass the Federal Aid in Wildlife Restoration Act of 1937, also known as the Pittman-Robertson Act. This act placed a tax on hunting guns and ammunition to pay for wildlife restoration efforts.

The 1930s also saw a major shift among the U.S. population that would end up benefiting wild turkeys, albeit unwittingly. The Great Depression forced many families to abandon their farms, leaving the land open for wild turkeys to expand into. As these farms slowly reverted to native grasses, shrubs, and trees, wild turkey habitat began to emerge, according to the National Wild Turkey Federations website.

READ MORE: What Life Was Like in the Great Depression

E. Donnall Thomas Jr., author of How Sportsmen Saved the World: The Unsung Conservation Effort of Hunters and Anglers, says the decline of cotton farms in particular may have helped wild turkeys rebound in states like Texas.

Thomas father, who won the Nobel Prize in physiology or medicine in 1990, recalls that there was nothing but raccoons, opossums and other small game to hunt growing up in Mart, Texas during the 1930s. But when Thomas traveled back to the area with his father around the 1960s, his father was absolutely astounded to see how wild turkey had flourished.

When he grew up there, all the land was planted in cotton, Thomas says. Cotton is terrible wildlife habitatnothing can eat it, it doesnt provide good escape coverand he was quite sure thats the reason that species like deer and turkeys werent there during the 1930s. When we went back, cotton was gone.

These changes in the 1930s provided good habitats for wild turkeys. However, their numbers didnt really start to rebound until the 1950s, because until then, conservationists couldnt figure out a good way to relocate wild turkeys to these habitats.

The conservation movement started bringing various species back around the turn of the century, says Jim Sterba, author of Nature Wars: The Incredible Story of How Wildlife Comebacks Turned Backyards Into Battlegrounds. But wild turkeys were [one of] the last species that got brought back because they couldnt figure out how to do it.

Finally, in the 1950s, conservationists realized they could safely relocate wild turkeys with rocket or cannon nets. These are nets that shoot out and trap animals. Because of relocation efforts, there are now millions of wild turkeys across dozens of states.

A wild turkey spotted along the highway in 1975, believed to be one of several wild turkeys once planted along the South Platte River in northeastern Colorado.

John G. White/The Denver Post/Getty Images

Thomas speculates that one of the reasons wild turkeys are able to thrive in Montana, the state he lives in, is because of a change in ranching habits that also took place around the 1930s. During this time, cattle ranchers began to bring their cows into feedlots near their ranch houses during the winter. The change in ranching habits had absolutely nothing to do with turkeys, but ended up providing them with a reliable food source to survive the winter.

Turkeys can eat cow manure, Thomas explains. They love to dig through manure, pick out undigested seeds and bits of corn and whatever the cattle have been eating In the winter, when theres snow, its not unusual to see 100 wild turkeys gathered around at a little feedlot next to a ranch building.

Although the food source is most important during the winter, when cattle are concentrated in one area, wild turkeys also eat cow manure in warmer seasons when the cattle are more spread out. Its very, very common to see wild turkeys in the spring flipping over cow turds, he says, adding, that food source wouldnt be here if the cattle werent here.

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How the Great Depression Helped Spare Wild Turkeys From Extinction - History