By CBC News Ottawa, August 6, 2017
After two decades of steady decline, Ottawa is starting to see more monarch butterflies around the city. In the early 90s, there were over one billion monarchs in Canada, but in the following years more than 80 per cent of them died off.
Forests being cut down and overusing pesticides contributed to the decline, Jeremy Kerr, a biologist at the University of Ottawa, told CBC Radio's All in a Day.
http://www.cbc.ca/news/canada/ottawa/monarch-butterfly-increase-ottawa-1.4231538