But this modern stampede is expected to dwarf those by sheer numbers. The numbers of adult monarchs reported from around the country have been astonishing. During the past two years, we've had very favorable conditions for monarchs. Taylor says the monarch population had survived last winter extremely well, and conditions in their summer habitats have been favorable. Two consecutive years of mild weather conditions throughout North America contributed to the large migration.
Monarchs have a life span of seven to eight months.
This generation of monarchs will winter in Mexico and then return to the United States and Canada in the spring to mate. Each year, hundreds of millions of monarchs migrate from their summer homes throughout the northern United States and southern Canada. From there, they fly to their winter roosts near Mexico City. Substantial numbers of monarchs have been reported from nearly all parts of the northern breeding range in recent weeks. Even areas such as New Brunswick and Nova Scotia, which typically have moderate to low monarch populations in July, have good numbers this year.