The 2018 Blitz by numbers

André-Philippe Drapeau Picard: Tuesday, September 11, 2018

The 2018 edition of the Blitz took place from July 28 to August 5. This year again, it was a success! Thanks to those who shared observations of monarchs and milkweeds during that period, we broke last year’s records. Here are some numbers demonstrating the energy invested by Mission Monarch participants during the Blitz.

by André-Philippe Drapeau Picard, Mission Monarch coordinator


That’s the number of milkweed plants that were monitored looking for caterpillars. It’s more than twice as much as last year! As monarchs only lay eggs on this plant, it is essential to know its distribution to find the butterfly’s breeding hotspots. Thus, it is important to share your milkweed observations, even if no monarch were found!


This is the number of caterpillars that were observed on milkweed plants. It’s almost ten times as much as last year! In fact, monarchs are very abundant this summer. It’s a good sign, but it doesn’t mean the population is re-established. Don’t forget that last December in Mexico, the population was at its lowest in three years.


That’s the number of participants. In other words, it’s you! You were almost twice as numerous as last year!


Finally, here is the number of locations where observations were made. Those sites are distributed in seven Canadian provinces and nine American states. Not bad! The larger the territory covered by your observations, the better our knowledge of monarch and milkweed distributions during the butterfly’s breeding period.

The 2018 Blitz is now over, but monarchs will still be around for a couple of weeks before they undergo the migration to Mexico! Keep an eye open and continue to share your observations until the end of the fall.

The Monarch Monitoring Blitz is an initiative of the Commission for Environmental Cooperation. It was organized by the Insectarium/Montréal Space for Life, Environment and Climate Change Canada, Monarch Joint Venture, the U.S. Fish and Wildlife Service, and Mexico’s Comisión Nacional de Áreas Naturales Protegidas.

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Monarchs are here!

André-Philippe Drapeau Picard: Wednesday, May 30, 2018

They’re back! On May 2, the first Canadian monarch observation of 2018 was reported. The butterfly was seen at Point Pelee National Park. How does this observation compare with past years? Let’s take a look at the archives…

by André-Philippe Drapeau Picard
Mission Monarch coordinator

Monarch nectaring on a goldenrod (Solidago sp.). Photo: André Sarrazin

In spring, some people seem seized with fever and exhibit strange behaviors. They are seen wandering in open areas, equipped with binoculars and huge cameras, actively looking around as if they were being watched. Those are the symptoms of the monarch fever!

In fact, many are impatiently waiting for monarchs to show up. The butterflies we saw leaving last fall have spent the winter in Mexico, in the sacred fir forests. In March, they left those overwintering sites and undertook their northward migration. However, monarchs arriving in spring in Canada are not those who left Mexico, but their descendants born in the United States.

A marsh at Point Pelee.
A marsh at Point Pelee National Park.

In Canada, first yearly monarch observations come from Ontario. In the Ontario Butterfly Atlas, which contains several thousand monarch records, a third of the first sightings happened in the Point Pelee National Park. This is first due to the fact that this park is the southernmost point of this province – and of Canada. Second, because Point Pelee extends into Lake Erie, it is the narrowest passage for crossing this Great Lake.

The Ontario Butterfly Atlas includes fifty years of monarch records. On average, first monarchs are observed on May 13, with a 20 days standard deviation. Thus, seeing one on May 2, like this year, is a little early but not exceptional. In fact, 11 out of the 48 first sightings were made in April!

How about Québec?

In Québec, monarchs arrive about a month later. Based on observations submitted to eButterfly, first sightings are made around June 13 on average. When will it be this year? We will know soon! Keep an eye open…

It is important to monitor migrating species, especially those of special concern such as the monarch, to predict challenges they may face. Climate change, for example, can modify migration patterns and accelerate plant growth, leading to a mismatch between migrants and their food ressources.

That invaluable information is known thanks to thousands of enthusiasts like you who share their observations on citizen science platforms such as Mission Monarch. In the end, the monarch fever is a good thing!

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Monarch population drops by 15%

André-Philippe Drapeau Picard: Monday, March 5, 2018

Last evaluation shows Eastern monarch population has dropped by 15% since last year. These worrisome numbers emphasize that more work is needed to understand and protect the migratory monarch, which is at risk of extinction.

By André-Philippe Drapeau Picard
Mission Monarch coordinator

Since a historical peak in 1997, the Eastern migratory monarch population has declined by 80%. This tendency, especially observed on overwintering grounds in Mexico, has alarmed governments and environmental groups across North America. In Canada, the butterfly was designated «special concern species» in 1997, then «endangered species» in 2016. Winter of 2013-2014 was the lowest year in terms of area, monarchs covering only 0,67 hectare. This year, the butterflies occupied 2,48 ha, which is the lowest record in three years.

Common milkweed, on which the monarch caterpillar feeds, has largely declined in the American Midwest.

What’s the matter?

The numbers published today are worrying. Last summer, monarchs were relatively abundant; thus we were expecting this abundance to be reflected in overwintering populations. This leads to believe something happened during migration. Did the late migration many monarchs went on had such an impact? Was it the consequence of extreme meteorological events on the way? It is too early to say.

Generally speaking, monarch decline is attributed to several causes: pesticide use, milkweed reduction, logging, climate change… Since the butterfly travels over great distances, through varied landscapes, it comes across obstacles of different nature. This a real puzzle for scientists and policy makers, who have to put all the pieces together in order to implement an efficient conservation plan.

But one thing is clear, migratory monarch populations are declining, and the faith of the migratory phenomenon is at risk. Researchers recently calculated that Eastern population quasi-extinction risk is near 60% over 20 years, according the worst-case scenario. To avoid this, the target in an overwintering area of 6 ha, which is more than twice what was observed this year.

There’s still work to be done

These numbers show there is still work to be done in order to understand and protect the monarch. To achieve this, we must go on research and habitat protection. Sharpening our understanding of the monarch biology and the factors affecting its survival will make it possible for us to give it adequate protection.

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Monarch summit meeting

André-Philippe Drapeau Picard: Tuesday, February 13, 2018

Participants at the Monarch Butterfly Research and Monitoring Workshop. Photo: Marie-Claude Rouillard (CEC)

The Monarch Butterfly Research and Monitoring Workshop was held in Montreal from February 6 to 8. Monarch conservation experts from Canada, Mexico, and the United States met to review the state of knowledge and define subsequent research priorities. Here is a summary of this busy trinational meeting.

By André-Philippe Drapeau Picard
Mission Monarch coordinator

Save the monarch; sure, but how? To halt populations decline and preserve the migration phenomenon, we need to understand the challenges the monarch faces all along its migration corridor. Even if it’s one of the world’s most studied insects, several questions remain unanswered. Here are examples of questions tackled last week by the experts at the workshop hosted by the Commission for Environmental Cooperation.

Common milkweed, one of the plants visited by the adult monarch.


Sharing the data

While Mission Monarch is the only monarch-dedicated citizen science project in Canada, the United-States and Mexico have many. Researchers from all three countries agreed on the importance of making their databases compatible and of putting together all information collected to date.


Document nectar resources

Monarch caterpillars feed exclusively on milkweed, but adults gather nectar from several flowering plants. Is nectar, the butterfly’s only energy source, available in sufficient amount during crucial steps of the insect’s life, such as egg laying and migration? Is the monarch competing with other insects for this sugar-rich liquid? To answer these questions, we first need to know which plants are visited by monarchs and, once identified, determine their distribution and abundance. Finally, we will have to predict, using statistical models, how blooming time and duration will evolve with climate change. With this information, it will be possible to identify the regions and periods where nectar could lack and manage habitats accordingly.


The caterpillar eats the milkweed on which its egg was laid.

Know your origins

Where are monarchs born? To this day, tagging has been the most used method to address this question. Unfortunately, of all tagged butterflies, only a little more than 1% is recovered and thus, bring precious data on their origin. An alternative approach consists in the study of isotopic signature. Molecules that compose monarch wings come from the milkweed eaten by the caterpillar on breeding grounds. Some of these molecules bear a «signature»; in other words, they are specific from the place they come. This method is powerful in that it reveals the natal origin of any given monarch, not only those that were tagged. Knowing the butterfly’s breeding grounds is essential for the protection of the species.

Researchers have a lot on their plate! Until the next monarch conservation trinational workshop, planned next year, those questions and more besides will keep them busy. Meawhile, the Mission Monarch team is preparing for another summer rich in missions with you! Your observations will contribute directly in answering the questions tackled during the workshop.


2018: The Mission Monarch team makes resolutions

André-Philippe Drapeau Picard: Friday, January 19, 2018

By André-Philippe Drapeau Picard
Mission Monarch coordinator

2017 has been an intense year, and we plan 2018 to be just as much! The survey filled by Mission Monarch participants in 2017 allowed us to identify your needs. So here are the team’s resolutions for the beginning year.


We want to see you again in 2018

If you did missions in 2016 or 2017, we would like to see you again in 2018! You can go back where you already did a mission, or venture into a new site! All your observations are important.


Photo: Daphné Laurier Montpetit

Have you to become heads of mission

Heads of mission are motivated persons recruiting participants and organizing missions. In 2017, near to 200 of you attended the workshop. Being aware of your enthusiasm, we’re pretty sure we can reach 500 this year! Contact us for details.


Mobilize enthusiasts from all over North America!

Your missions!

Most participants come from Ontario or Québec. This year, we wish, of course, to keep getting data from these two provinces, but we aim for more observations in other provinces where monarchs breed, as well as in the United States and in Mexico. We know there are monarch enthusiasts over there!


Photo: Daphné Laurier Montpetit

Mobilize the youths’ energy!

We are working on a mission format adapted for elementary schools and day camps. It should be ready this spring, just in time for the arrival of the monarchs.


Improve our web site

The Mission Monarch website goes through a facelift! More userfriendly, it will be online this winter.


Looking forward to meet you during new missions!

The Mission Monarch team

Time to celebrate!

André-Philippe Drapeau Picard: Friday, December 15, 2017

By Daphné Laurier Montpetit
Coordinator of the Mission Monarch project

With the holidays approaching, we can only raise our glasses to the participants of Mission Monarch! For this second year of existence, the project has exceeded expectations.
Dear citizen scientists, here’s to you!

2017 overview

Many of you have mobilized for the monarch. This year alone, you have conducted more than 1000 missions on 423 different locations. A total of 31,519 milkweeds were scanned for monarchs. These figures represent more than double (and sometimes triple) of last year’s results.

And the monarchs were there! We count 882 mentions of caterpillars and 2443 mentions of adults. Although some identifications remain to be confirmed, we can say that this summer was rich in monarchs! Hopefully, this trend will be confirmed in the official annual count, to come early in 2018.

Heads of Mission

Another good news reinforces our pride, at the end of this year. In July, we launched, for the first time, a Head of mission training tour in Ontario. More than 100 participants attended a two-hour workshop to learn how to organize group missions in their area.

The tour was a success, and will definitely be back next year. If you are interested in taking this free training, email us!
We have a lot to celebrate at the end of the year, before we start again in a new season, and we thank you!

We wish all of our participants a wonderful holiday season and a great new year. We look forward to seeing you in 2018, for a new year, filled with milkweed!
Happy Holidays!

The Mission Monarch Team

What do monarchs do during winter?

André-Philippe Drapeau Picard: Friday, November 10, 2017

by Daphné Laurier Montpetit
Mission Monarch coordinator

We see them go away – with some sadness – in fall. We know that they will be migrating for thousands of kilometers, and that their descendants will be back with the summer. But what’s going on between fall and spring? What do monarchs do during winter?

Heading South

Monarchs spend the winter in central Mexico mountains, in the state of Michoacán. Year after year, they find shelter in the sacred fir forests. Mexico may evoke sun, heat and beaches, but the butterflies prefer a whole other environment!

Since monarchs can’t bear winter temperatures in the United States and Canada, they migrate south to avoid freezing. However, they are not looking for hot weather, but rather cool places.

The goal of the migration is to find the perfect climeate: warm enough to avoid freezing, but cold enough to allow the butterflies to survive until spring. Thus, the temperature in the overwintering areas varies between 1 and 6°C.

Put in on pause… for the diapause!

Under warmer temperatures, monarchs would keep their normal metabolic rate. For example, in summer, adult monarchs live for one month. Then how can they survive over seven winter months and still be able to reproduce in spring?

Monarchs of the migrating generation have a couple biological tricks to live that long. One of these ticks is the diapause, a period of time during which development stops. It’s a kind of dormancy, allowing the buttefly to spare its fat reserves, stretching its lifetime. The cool temperatures in the overwintering sites allow this important metabolic slowdown.

A fragile equilibrium

This perfect environment where monarchs spend the cold season is unfortunately very delicate, and several factors trouble its equilibrium. One of them is logging, inside or around overwintering areas, since it can result in a higher exposition to wind and, consequently, higher temperature fluctuations.

Climate change also worries researchers. Warmer temperatures could affect diapause as well as disrupt the internal compass which the monarchs need for migrating. Storm frequency is espected to increase with climate change, which greatly disturb the diapause, as it did in spring of 2016, when millions of monarchs were killed during a snow storm.

Despite the challenges, the butterflies are back once again at the sites visited by their ancestors, ready for another winter. The Mission monarch team is already looking forward to see them back. Are you?

Photo: Anita Ritenour

How do monarchs find their way?

André-Philippe Drapeau Picard: Thursday, October 19, 2017

By Daphné Laurier Montpetit
Mission monarch coordinator

The monarchs of North America are known for their spectacular annual migration from Canada to Mexico. Each fall, the butterflies undertake a 4000 km journey to the oyamel fir forests, in central Mexico, where they spend the winter. Once spring arrives, they are off again for a northern migration that will spread over several generations.
If the distance traveled by the monarchs is impressive, their ability to find their way is no less! How do monarchs navigate to their destination, year after year?

A sophisticated internal compass

Not all monarchs are drawned to the South. In experiments using a flight simulator, only the “fall” butterflies demonstrated a clear direction in flight. Instinctively, they head southwest.

Migratory monarchs rely on the sun to know the direction to follow. However, since its position changes during the day, the simple observation of the sun is not enough. Imagine the zig-zag that a butterfly would do just by following the sun, every day, from east to west!

To solve this problem, migratory monarchs rely on a biological clock, located in the antennas. This clock tells them the time of day. With this information, the butterflies can adjust their position relative to the sun, in order to maintain the course towards the southwest: in the morning, they keep the sun to their left and in the afternoon, to their right.

These two combined information – the position of the sun and the time of day – constitute the internal compass enabling the monarchs to navigate to Mexico.

What about cloudy days?

Occasionally clouds hide the sun, depriving the monarchs of their visual cue. Fortunately, butterflies have more than one trick up their sleeve!
In addition to the biological clock, the indispensable antennas of the butterfly contain a “magnetic compass”. This tool tells monarchs where they are in relation to the equator. They can therefore find their way to the south by relying on the lines of the earth’s magnetic field. Impressive, right?

Heading north!

In spring, everything changes! The monarchs who spent the winter in Mexico go on migration, but this time, in the opposite direction. The same mechanism comes in, but with a major change: the internal compass has been recalibrated, during the winter, to indicate the north. It is believed that exposure to cold triggers this recalibration.
Several mysteries still surround the navigation methods of monarchs and each season unveils new answers. Certainly, these great travelers will never cease to amaze us!

The Monarch and the Painted lady: do you know how to differentiate them?

André-Philippe Drapeau Picard: Friday, September 15, 2017

By Daphné Laurier Montpetit
Mission Monarch coordinator

It is called the Painted lady (Vanessa cardui), and it is the most common species of butterfly in the world. In Canada, it seems to follow a cycle: rare in some years, it returns in great numbers other summers. This year, observations of this species abound. With its orange wings, it can remind us of the monarch and deceive the eye of several observers.

Do you know how to differentiate it from the monarch?

Some similarities…

Like the monarch, the painted lady belongs to the family of nymphalids. It is also a migratory species that, having flown in Canada from April to October, migrates to the southern United States or to Mexico for the winter. Two or three generations can be observed during the summer.

… and differences!

If its colors can recall those of the monarch, the patterns displayed on its wings are quite different. The painted lady has no black veins, like those of the monarch, but rather brown spots. On the back of its hind wings, visible when the butterfly has its wings closed, we can distinguish four ocelli – round spots recalling eyes.

With a wingspan of about 6 cm, the painted lady is also smaller than the monarch, which can reach up to 10 cm wingspan. The flight of the painted lady is rapid and erratic, unlike the slow floating of the monarch.


Have you seen painted ladies?

At first glance, the two orange butterflies can easily be confused. To make sure you report the right butterfly, take pictures. The pictures are a great help to confirm the identifications. You can also rely on the Monarch Identification Sheets and the Commonly confused form to validate your observations.

Remember to report monarch observations on the Mission Monarch website. And if you saw painted ladies? Contribute to the research on butterflies, by reporting your observations on eButterfly! Your Mission Monarch login information also works on this site.

Good butterfly watching!

Painted lady
Painted lady
(Photo: André Sarrazin)
(Photo: André Sarrazin)

A breathtaking Blitz!

André-Philippe Drapeau Picard: Thursday, August 17, 2017

By Daphné Laurier Montpetit
Mission Monarch coordinator

From July 29th to August 6th was held the second Mission Monarch Blitz. This year again, the participation (of the citizens and monarchs!) exceeded the expectations. Here is a summary of the week, in numbers.


During the nine days of the Blitz, 115 participants submitted more than 249 missions, exceeding in one week the total number of missions of the 2016 season!
A mission is any outing during which one or more milkweed plants are examined in search of monarch caterpillars and for which observations are shared on the website. People from several Canadian provinces (and even some American states) carried out these 249 missions.


Is the number of milkweed plants inspected by our citizen scientists during the week. This is excellent news, since the host plant of the monarch is at the heart of the mission. The research behind Mission Monarch focuses on identifying the best breeding habitats of the monarch butterfly, and milkweed is an essential part of it. In short, it is as important to document the host plant as the presence of the butterfly. The data collected on milkweed are therefore very valuable, even if no monarchs are found.


Experts agree: we are, so far, witnessing a better year for monarchs. Monarchs observations are on the rise throughout its breeding range, and the 606 adult monarchs reported during the Blitz are only supporting the trend.

The size of populations of migratory monarchs is calculated by counting the number of hectares they occupy during their overwintering season. Based on this summer’s assessment so far, we are hopeful that this year’s count will meet the 2010 and 2015 numbers. Back then, the eastern population covered just over 4 hectares. Still below the last 25 years avergade of 6 hectares, but compared with the 0.67 hectares occupied in 2013, this is a step in the right direction!


They are the stars we hoped to see, and they were there in numbers! During the Blitz, 223 caterpillars were spotted on milkweed plants inventoried.

Caterpillars provide clues to the quality of summer breeding sites. Where they are (and survive), we know that the conditions are adequate. By listing sightings of monarch caterpillars, a map of the most productive habitats can be identified and prioritized to optimize the conservation efforts of the monarch.

No time to rest for monarchs!

The Blitz is over, but for monarchs, the biggest job is coming! The caterpillars that will be observed over the next few weeks will be those that, once adults, will undertake the long journey to their overwintering areas in Mexico. Let’s enjoy their last days among us! The missions carried out in the late summer are just as useful as those during the Blitz.

So, dear participants, we count on you to get back out there and look for caterpillars!
Good missions!