http://mexiconewsdaily.com/news/sharp-increase-seen-in-butterfly-numbers/?utm_source=fb&utm_medium=fb&utm_campaign=butterflies-negative-ngos

Monarch butterflies have arrived in the Michoacán and Estado de
México sanctuaries by the millions, numbers that far exceed those recorded in
2014-2015, according to estimates by federal authorities and universities.

A month after the first monarch arrivals were recorded, the butterflies’
presence now covers more than four hectares, a sharp increase from last year’s
1.3 hectares. In numbers, it is estimated that 160 million monarchs have arrived
in the annual migration from the U.S. and Canada.