What changes did george bird grinnell observe? what group did he begin?

George Bird Grinnell observed the wild-lands and he noticed that the number of certain animals was so low that they had become endangered. His most notable observation was made regarding the American Buffalo or the Bison. He noticed that their numbers were dwindling and initiated programs to preserve them and prevent their extinction.

He opened the Boone and Crockett Club. This was a club made by him, General William Tecumseh Sherman and Gifford Pinchot, and they devoted the group to the restoration of American Wild-lands. They wrote books and papers and organized projects and initiatives to protect nature and animals.