Monarch migration: an awe-inspiring spectacle

Today’s post comes from Laura Penner, aNatural Heritage Education Leader at Rondeau Provincial Park.

September is a great time to come out and enjoy all of nature’s colours. The goldenrod is in bloom, and the vibrant purple blooms of cylindrical blazing star dot the dunes along Lakeshore Avenue. You may even see the black and orange wings of a monarch butterfly as it stops to feed on one of these colourful flowers.

This month is migration season for these amazing insects. In late August monarchs east of the Rocky Mountains begin a southerly journey which will take them over 3,000 km to the mountains of Mexico. They can often be seen flying in large groups, feeding on nectar rich flowers along the way until they reach the exact same winter roosts used by countless generations of Monarchs before them.

Monarch butterflies forming a roost during fall migration (Photo Credit: Brett Groves)
Monarch butterflies forming a roost during fall migration. Photo: Brett Groves

Monarchs spend the winter months in a dormant state in fir trees 10, 000 feet above sea level. The climate of this region provides the perfect conditions for the Monarch’s survival. Temperatures close to freezing, high moisture and a thick canopy are exactly what the Monarchs need to make it through the long winter months.

As the weather begins to warm in March, the Monarchs once again begin to stir. These particular Monarchs have already survived a long southerly flight, the sometimes unpredictable weather of their mountainous roosts, predatory birds and other hazards along the way and are now responsible to produce the next generation of Monarchs. As they fly northward they begin looking for Milkweed plants to lay their eggs on. The offspring of these migrants have a much shorter life span than their parents and therefore it can take up to three generations of Monarchs before we start seeing them in Canada in the spring.

The Monarch migration is one of nature’s mysteries, one which several Canadian entomologists, Fred and Norah Urquhart, were instrumental in solving.

Each year, we celebrate this amazing flying insect during our Migration Festival in September.  To find out when this year’s festival is taking place, check out our events calendar.

Come enjoy this spectacular event this September in Rondeau Provincial Park before the Monarchs are gone for another season.  And if you are planning a road trip northwards, Science North in Sudbury has recently released an IMAX production on this Canadian Discovery.  You can watch the trailer here .

Ever wonder why some years we see hundreds of monarchs and other years very little? It’s normal for the Monarch population to vary from year to year, but researchers believe that there are a few key challenges facing populations of monarchs.

  • harsh weather and storms
  • loss of wintering habitat
  • habitat loss

A fantastic, beautiful and easy way to help monarch is by planting native wildflowers, especially milkweed, which the caterpillars need for food.