Data from monarch monitoring blitz aids conservation efforts, count volunteers welcome

This south shore monarch was tagged while nectaring September 7.

MANITOULIN – Manitoulin’s third annual monarch butterfly count is expected to go ahead but it will be later and on a smaller scale, said Theodore Flamand. He works with the Species at Risk program through Wiikwemkoong’s Lands and Resources department, the host of the count. Details and dates have yet to be finalized. Judith Jones, count co-organizer from previous years, is unable to organize a count this year due to other commitments. The count would typically get underway at the end of July.

Ms. Jones had intended to submit the data from the count to Mission Monarch, which is the Canadian central organization for monarchs, similar to Monarch Watch and other US programs. “I’m disappointed I couldn’t pull it off,” she said. “There are so many monarchs this year. If anyone is counting, which I will likely do myself, please consider submitting the data to Mission Monarch.”

Mission Monarch is a community science program that does surveillance of milkweed and monarchs from spring until fall every year. Along with the US programs it attempts to capture the distribution and the density of monarch populations during that time. The International Monarch Monitoring Blitz is a trinational, 10-day activity during peak monarch activity that aims to provide a valuable snapshot for scientists of the monarch population status across the butterfly’s migratory route through Canada, the United States and Mexico. The blitz runs from July 23 to August 1 this year. This survey of milkweed for monarch eggs, caterpillars, chrysalises and butterflies will help researches identify priority areas for monarch conservation actions.

Alessandro Dieni, of Insectarium de Montreal, is the Mission Monarch coordinator for Canada. “That’s the moment when we normally have the most monarchs in the summer breeding range,” he said. “The monarchs overwinter in Mexico by the millions. It’s easier for scientists to go into the forests where colonies are overwintering and estimate the area the monarchs are occupying. In the summer, very few monarchs can be seen in Mexico but their territory covers a larger area, southern and northern states and Canada. It’s impossible for only biologists to count like they do in Mexico and that’s why we ask for help from volunteer citizen scientists.”

Canadians are more and more participating in monarch monitoring and the blitz specifically, Mr. Dieni said. “We had roughly 700 observations in 2017 from 100 participants, 900 observations in 2018 from 500 participants and then in 2019, we had 2,700 observations from nearly 1,500 participants.”

Gathering information on the species at different times of the year is important. Declining population numbers are a capture of what’s happening in Mexico year over year. The population in Mexico has seen a roughly 80 percent decline since the mid 1990s. It has stabilized over the last five years but remains under a threshold level necessary for the population level to be constant. “Under that threshold, we might see an extinction,” Mr. Dieni said.

“We have information about the population since the mid 1990s in Mexico but we’re not sure if the populations are fluctuating in the same way in the summer breeding range,” he said. “Having programs like Mission Monarch and the US programs help us have a better understanding of the population dynamic of the species in the summertime.”

Mission Monarch undertakes the work of population monitoring but creating and maintaining habitat is something that’s also important. The data obtained from the blitz and the longer monitoring programs can be used to make better decisions. “One of the things we’re trying to determine is where the hotspots are for monarchs. In Canada what we see is only the breeding population. By identifying hotspots we’ll know what to protect to have a healthy population year after year,” said Mr. Dieni.

In a Facebook post Ms. Jones said, “The best way to help the monarchs here at home is to make sure their food source, common milkweed, does not get trampled or mowed down. If monarchs are present, it is best to make sure no one steps on the plants or drives over them.”

Every observation is of high value, he added. “Another thing we emphasize is that milkweed is also the basis of an observation. If people see milkweed in their surroundings but there are no monarchs, eggs or caterpillars, these are still important observations to share. Milkweed is the sole plant that monarch caterpillars will feed on and without observations of milkweed, with or without monarchs, we are not getting the full snapshot. We say in science that zero observations are still observations.”

In fact, finding milkweed is the first step. Counting monarchs flying around, eggs on the leaf or caterpillars feeding is the second step, followed by sharing the observation on the website, mission-monarch.org.

2020 saw less observations so researchers are anxious to see more this year. Even considering fewer observations, however, there were lower numbers when viewing the ration of caterpillars per milkweed stand examined. In 2019 there were approximately 24 caterpillars per 100 stands examine but that fell to eight caterpillars per 100 stands in 2020. They’re hoping for more of both in 2021: more observations and more caterpillars. “The general impression everywhere in Canada is numbers are higher this year,” Mr. Dieni said. “The monarchs came in earlier this year than in previous years and them seem to have laid more eggs. We seem to be seeing more monarchs and more caterpillars.” He expects to have count numbers by the end of August.

Mr. Flamand agrees numbers are higher on Manitoulin this year. “They’re everywhere,” he said. “It must have been a good winter in Mexico. It’s kind of hard to imagine that they fly to Mexico, being so little. They are a totally amazing animal.”

Join the trinational blitz at mission-monarch.org and watch The Expositor for details of the Manitoulin monarch count.