How many monarchs will you see this summer?

André-Philippe Drapeau Picard: Wednesday, June 8, 2016

By Sonya Charest

As a monarch passionate, you are undoubtedly hoping to observe dozens and dozens during your outings in the field and this is clearly what we wish you. However, nothing is ever guaranteed in nature. If you come back empty handed from observation outings, don’t despair. Your data is as valuable for research. Here’s why.


The monarch’s annual cycle follows a particular phenology. For example, your outings in the field can begin as soon as milkweed comes out of the ground in the spring. However, generally speaking this happens much earlier then when the first females arrive ready to lay their eggs! It is therefore to be expected that during your first outings you might find none of those sought after eggs and caterpillars. While it is nearly impossible to predict when exactly monarchs will arrive in your nearby fields, it may take a few outings before you find your first eggs and caterpillars.

You must also consider that throughout the summer, successive generations of monarchs help increase the monarch population. Therefore, it’s not because there were no monarchs present in your field during the first summer generation that you won’t find any later in the season.

Add to this the annual variations of the overall population size with recently very small populations and you will understand that it is nearly impossible to predict the presence, if, and when monarchs will show up at your monitoring sites.

However, it is your regular visits, those where you will have observed or not monarchs that will allow scientists to better understand the reproduction capacity of monarchs in Canada. Hence, let us not forget that writing down a zero where you are reporting the presence of the king of butterflies still says a lot, perhaps as much as any number.

Finally, it is important to remind ourselves that the goal of Mission Monarch is to describe and point out the best breeding habitats to preserve. Sites where we find milkweed that contain no monarchs even where milkweed is abundant provide extremely valuable information. Researchers need this data as much to better target conservation actions.

Your greatest challenge dear participants will be to never forget the importance of regularly monitoring your sites throughout the season, whatever the result of the previous outings may be. We sure won’t forget that your participation is essential to the success of this project.