There are a lot of reasons for these laws existing, though many will seem odd now since it's something that has been extremely illegal for about a century now.

Native people have string cultural tradition in which Eagle feathers and others are important. While they are the only ones allowed to possess them, it's only after a very extensive process. People are willing to pay ridiculous money to "jump the line."

When the time these laws were passed, art and fashion used feathers and animal skins. The flashier or more amazing the animals, the more parts were worth. Raptors especially, being apex animals, don't reproduce very quickly, and it is very easy to hurt their populations, and as they are the biggest, baddest birds, their feathers are top choice. Talons were also in demand, again, because they are pretty awesome.

People also just used to collect weird stuff, including dead animals. Tour the house of a rich person from the 1700s or 1800s house and you will likely find all manner of dead animals. These people did the same thing as people do online now. They wanted to look more awesome than everyone else in their social circle. Looking like a fancy biologist, explorer, or hunter made you seem interesting, and all you had to do is kill something fancy looking, or pay someone to do it for you.

Here are 2 news stories for you. The first is still going on from this year. Two men killed at least 3600 birds for profit in 6 years. That's just 2 people.

In the second story, it is people and businesses selling animal parts from all over the world. It's like shark fins, elephant tusks, pangolin scales, and so on. They're rare, and people will pay.

Man pleads guilty in eagle ‘killing spree’ on reservation to sell feathers on black market

A Washington state man accused of helping kill thousands of birds pleaded guilty in federal court on Wednesday to shooting eagles on an American Indian reservation in Montana and selling their feathers and body parts on the black market.

Branson and a second defendant, Simon Paul, killed approximately 3,600 birds, including eagles on the Flathead reservation and elsewhere, according to a December indictment.

Federally recognized tribes can apply for permits with the U.S. Fish and Wildlife Service to take a bald or golden eagle for religious purposes, and enrolled tribal members can apply for feathers and other bird parts from the National Eagle Repository in Colorado and non-government repositories in Oklahoma and Phoenix. There’s a yearslong backlog of requests at the National Repository and researchers say the high demand is fueling the black market for eagle parts.

17 people, 2 pawn shops sentenced in eagle trafficking case

Parsons’ office said the operation used undercover techniques to buy protected bird parts from 51 suspects over 19 months. Authorities said the purchases happened over the internet and in Iowa, Montana, Nebraska, South Dakota and Wyoming.

Edward Grace, acting assistant director of the Office of Law Enforcement for the U.S. Fish and Wildlife Service, said in the statement that agents and forensic scientists found more than 35 bird species — spanning every continent but Antarctica — had been trafficked.

“This operation, which began in America’s heartland, illustrates how wildlife trafficking is a global crisis,” Grace said.