The monarchs have left

Faithful to instinct, the monarchs have hit the road for Mexico. The autumn migration is a great adventure, but one that only an estimated half of the butterflies survive. And with climate change, the challenge they face is even greater…

by André-Philippe Drapeau Picard, Mission monarch coordinator

Surviving the chill

Every year for millennia, monarchs have been leaving us and heading south. Don’t take it personally: they simply can’t put up with our winters! In the forests of sacred fir (Abies religiosa) where the butterflies take refuge while waiting for spring, temperatures slightly above freezing are ideal for their survival. They keep them from freezing themselves while slowing down their metabolism, which allows them to conserve energy. But the road to their wintering area is filled with obstacles.


Risk of fuel exhaustion

First of all, to pull off this migration of over 4,000 kilometers, it takes fuel. The fuel for butterflies is nectar from flowers. To avoid breakdown, they have to gas up before taking off! However, where flowering meadows were once plentiful, now there are mostly fields with crops growing that produce little or no nectar. The habitat loss resulting from intensive agriculture is a hurdle to the monarchs’ autumn migration.


Drought and hurricanes

Another considerable challenge is that of climate change, the impacts of which on the monarch’s migration we’re only beginning to understand. For example, precipitation is less evenly distributed, which results in periods of drought alternating with heavy rains. In a period of drought, the growth rate of plants slows, and they produce a nectar of lesser quality.

In addition to drought, climate change increases the frequency of extreme weather events such as hurricanes and tornadoes. When those storms take place during the migration, and that’s the case in the fall, monarchs die off in much greater numbers. For example, this year the first migrants ran into hurricane Florence, which struck the American east coast in mid-September. What was the impact on the monarchs’ survival? We’ll only know when the results of the annual inventory drawn up in the Mexican wintering sites are available.


Protection still necessary

Even though monarchs were very abundant this summer in their breeding grounds in Canada and the northeastern U.S., that doesn’t mean that their decline has been halted for good. It just takes one difficult migration to reduce the population drastically. Meaning, to see how the number of monarchs evolves year after year, it’s vitally important to continue taking part in Mission Monarch!

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The 2018 Blitz by numbers

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!

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%

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

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 monarque 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

By André-Philippe Drapeau Picard
Coordinator of the Mission monarque project

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!

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 at
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?

by Daphné Laurier Montpetit
Coordinator of the Mission monarch project

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?

Destination sud

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?

By Daphné Laurier Montpetit
Coordinator of the Mission monarch project

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?

By Daphné Laurier Montpetit
Coordinator of the Mission monarch project

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)