It is that they are endangered animals.
The textbook example was that for many years, the US government claimed ownership of all bald eagles, and parts thereof. And this got weird, because eagle feathers are a big part of Indian religious ceremonies. At first, when a dead eagle was recovered, the government would remove then laser serial number each feather shaft. Tribes would have to request a given number of eagle feathers for a particular event, the paperwork would take months, then sign for the feathers. Then after the ceremony they would be returned to the government.
Violating the rules, killing an eagle or even harvesting a dead eagle had a whopping fine and jail time.
Fortunately, because of the eagle woman up in Alaska, there is now a surfeit of eagles. Turns out the solution to an endangered species is making more of them.
http://www.baldeagleinfo.com/eagle/JeanKeene.html
Just like "the King's game"....