Species at Risk Profile – Monarch Butterfly

 Megan Miller

August is the month of the Monarch butterfly here at South Shore Joint Initiative. With a special webinar presentation by David Bree that happened this week and Flight of the Monarch Day this weekend, our days are filled with these easily recognizable insects. What better way to continue to celebrate the species than to have them as our Profile Species this month?

Likely the most recognizable butterfly in Ontario, this species is orange with black web like lines running through the orange base, with white spots bordering the wings. As a caterpillar, they are white, yellow, and black-banded.

 Photos by Ian Dickinson

Monarchs call home from Central America to the southern parts of Canada. In Canada, Monarchs are most abundant in southern Ontario and Quebec where milkweed plants and breeding habitat are widespread. In late summer and fall, Monarchs migrate to Mexico where they spend the winter months avoiding the cold Canadian climate (jealous much?). During migration, groups of Monarchs numbering in the thousands can be seen along the north shores of Lake Ontario and Lake Erie!

The Monarch butterfly is considered Endangered in Canada. There are many factors influencing the decline of the Monarch which include climate change, destruction of their overwintering homes in Mexico, insecticides, and invasive species. Monarchs exclusively lay their eggs on milkweed plants. In their larval stage, they only eat milkweed. However, Monarchs have been laying their eggs on the invasive milkweed, Dog-Strangling Vine. Unfortunately, the larvae are not adapted to this milkweed and they don’t survive on it.

Can you tell the difference between a Monarch Butterfly and a Viceroy Butterfly?

Photos by Ian Dickinson

Although Monarch and Viceroy butterflies can be difficult to tell apart, there is a simple distinguishable difference. Viceroys have a black horizontal line going through the veins of their hind wings (the bottom two wings). The Viceroy is typically a little bit smaller than the Monarch, but if you don't have them side by side for comparison, this won't be the best way to help decide whether you've seen a Viceroy or a Monarch.

You can learn more about the Monarch and how you can help them by visiting the Monarch Page on the Government of Canada website