… Nature Challenge calls on Canadians to become citizen scientists … Academy of Sciences. In Canada, the Canadian Wildlife Federation (CWF) and … to the increase of Canadian participation, more than 400 … to Canada: Elm zigzag sawfly, a forest pest native to …… Nature Challenge calls on Canadians to become citizen scientists … Academy of Sciences. In Canada, the Canadian Wildlife Federation (CWF) and … to the increase of Canadian participation, more than 400 … to Canada: Elm zigzag sawfly, a forest pest native to …