First monarch butterflies arrive on Manitoulin

This female monarch butterfly is in excellent shape for having just flown across Lake Huron. photo by Joe Shorthouse

MANITOULIN – The first observations of spring suggested by the organization Journey North as they assemble information on the northward movement of monarch butterflies is the appearance of milkweed shoots as they poke through the soil surface.

My wife Marilyn and I have been monitoring known patches of milkweed on sandy soils in Providence Bay this spring and as May 13, there was no sign of sprouts. Since spring this year appears to be one to two weeks later than usual, we did not expect to see any signs of monarchs until June.

However, to our delight, we not only found new shoots ranging in size from four to eight cm in height, on Sunday, May 26, a couple of them had eggs of monarchs. This meant that at least one monarch had arrived in the area.

As I took photographs of the shoots and eggs, two female monarchs floated across the road near the ice arena, landed on shoots in front of us, and started laying eggs.

Both females were weary and wouldn’t let me get closer than about five metres. They quickly took flight when I approached, making photography difficult, but the most exciting part of our Sunday observations was the realization that these butterflies had just flown across Lake Huron from Michigan. This would have made their recent flight the longest over water by any North American monarchs. 

All three monarchs we saw on Sunday were in good shape with bright colours which likely meant that they are part of a new generation from northern United States.

It was the grandmothers or great grandmothers of these new Manitoulin butterflies that had overwintered in Mexico. The overwintering generation would have died along the way after laying eggs and it was the first or second new generation that made it to Manitoulin.

The weather on Manitoulin Island last Thursday and Friday was warm, but Saturday was cool, rainy and windy—conditions that force monarchs to cling onto shrubs or small trees. It is unlikely that the Providence Bay monarchs flew across Lake Huron during the rain storm on Saturday, which means they arrived either late last week or possibly on Sunday. 

Most of the islands in the Great Lakes where people live year-round are participating in a monarch monitoring project in 2019 and it will be interesting to see maps showing the wave of monarchs from the southern shores of the Great Lakes onto the islands and then beyond the northern shores.  

When readers of The Expositor see their first adult monarchs, eggs, or caterpillars, they are urged to record their observations with Journey North at JourneyNorth.org/monarchs.