The video title wants to draw attention to the sound, which is frankly unimpressive (or incompletely captured by the film crew). What is impressive is the superabundance of the natural world and the impressively high resolution of the video images (compared to what is usually displayed from tourist cameras). For videos like this I always recommend clicking the fullscreen icon (lower right).
According to Journey North monarch map, migrating adults have now been seen as far north as Illinois and Iowa. None reported yet at the Wisconsin Butterflies site. I expect them in our yard probably toward the end of next week, because our milkweed spikes have already appeared.