Yes, Monarchs, the movie, well real title is Flight of the Butterflies. I just saw it at our local IMAX/3D theater at the natural/local history museum. Amazing! I follows the migration and life cycles of the monarchs from Mexico on up through the midwest and eastern states into Canada. Central to the story line is Dr Urquhart from Toronto who has made this his life's work. He figured out how to tag them and get as many people as possible in on the tagging. Finding the butterfly trees in Mexico the Eureka moment.
As a side note, when I was in jr high in Massachusetts did a science fair project on the monarchs and migration. Dr Urquhart was the go-to person and I have a letter from him on the butterflies. (a little bit before internet and e-mail!) I need to dig around and see if parts of the project are with me or gone in the many moves.
Plant more milkweed!