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A summer searching for monarchs and milkweed

Marian MacNair
A summer searching for monarchs and milkweed

Citizen-science programs are of great importance for research in conservation, especially in the case of the monarch butterfly. Nevertheless, it is still vital to have graduate students who explore specific issues in order to get specific answers. So this is what a summer in the field can look like when we are aiming for a better understanding of the monarch.

What makes the north shore of Lake Ontario so attractive for monarchs?

That is the question that Marian MacNair and her two supervisors, plant science researcher Sylvie de Blois of McGill University and Insectarium de Montréal director Maxim Larrivée, have been asking themselves. In fact, a good part of Marian MacNair’s master’s degree is devoted to answering that question, which at first glance may seem quite straightforward. To find the answer, Marian had to visit 80 locations north of Lake Ontario during the summer of 2019. She made a three-week tour in late June and a second tour in early August, racking up more than 6,000 kilometers of driving in five weeks. The areas visited consisted of zones both where monarchs are found in large quantities (such as the northeast shore of Lake Ontario) and where they appear to be less frequently seen (between the cities of Toronto and Hamilton).

A day during summer 2019

With so many locations to sample in so little time, Marian had her hands full. Accompanied by her daughter Maeve, 14 years old, who could put up with a lot as long as there was a shower, wi-fi and ice cream at the end of the day, she visited an average of six sites daily. For each one she measured certain environmental data, such as temperature and wind speed, but also the type of environment and landscape. Next, Marian identified all the plants found on 12 one-square-meter plots of land distributed across the location (over 300 different species were identified over the summer). Then they would tally the monarch eggs, caterpillars and butterflies encountered. Every leaf on a milkweed plant was meticulously inspected for the presence of eggs and caterpillars. A task that must have taken a lot of patience ‒ just ask Maeve, who had more than 400 plants to inspect at one point!

Not always a walk in the park

Even if roaming through picturesque landscapes in search of monarch butterflies may strike us as a dream job, sometimes you have days that aren’t so good. An isolated site in the Ganaraska Forest will stay etched in Marian’s and Maeve’s memory for quite a while. To get there they had to take an ATV road buried in poison ivy that smeared all over the sides of the car. Later, inspecting the milkweed plants, Marian had the bad luck of stepping on a wasps’ nest. Result: about 20 stings on both elbows! And to make things worse, there was no way to find a place to rest and take a nice bath that evening, because an international lacrosse tournament had monopolized all the hotel rooms in the vicinity. They had to make do with a room in an unsavory neighborhood ‒ happily, nothing else happened to them that day!

All in all: a remarkable experience

Despite all the work involved, according to Marian and Maeve the summer was wonderful. First, weather conditions were ideal for observing monarchs. For example, their day on the site of the Uxbridge Countryside Preserve was extremely productive: over 100 monarchs were spotted in just a few kilometers.

Also,  over the course of their expeditions, they encountered monarch fans who attached great importance to conserving the species. Among others they met was a woman who created a magnificent garden for monarchs on her land; a budding young entomologist who made a note of all the insects encountered during the summer (including the monarch!); and a woman who, for five years, had been tagging monarch butterfies to study their migration (two monarchs she tagged last summer have even been spotted in Mexico!) All fine examples of citizen contributions to preserving this extraordinary butterfly.

Since then, Marian has been busy analyzing the data collected last summer. We are looking forward to the conclusions she reaches. Meanwhile, she has fun recounting how the monarch seems to especially enjoy places where it can be found together with…mosquitos, thistle, poison ivy and wasps!

To learn more about Marian’s project, and how her analyses are progressing, feel free to consult her blog.

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