Conservation & Preservation

Threats to Monarchs

As is noted in the film, a staggering 99% of monarch eggs and caterpillars do not survive to become adult butterflies. They are a significant food source for birds and other insects. That is why, for the remaining 1%, it is necessary to ensure that the monarchs are not threatened and survive so that the critical mass required to sustain their migrating and overwintering population is conserved and maintained.

Scientific Advisor to Flight of the Butterflies & Director of Monarch Watch, Dr. Chip Taylor, gave a thorough presentation at the Royal Ontario Museum in the Winter of 2012, entitled “Monarch Butterfly Conservation: The Challenges Ahead” that reviewed the many factors affecting the monarch butterfly and its migration. Based on the recent data of continued declining Monarch numbers, Dr. Taylor has outlined a Recovery Plan to restore the Monarch population. “Restoration of the Monarch population is not going to be cheap or easy. Bringing back the Monarch has to be a national effort,” states Dr. Taylor.

At the time of Dr. Urquhart’s discovery of the migration in 1976; it was estimated there were about a billion butterflies. Today, sadly, it is estimated that there are about 1/2 billion, perhaps much less, making the migration threatened. That is why it is so important that the short-term and long-term threats to the monarchs are closely examined and acted upon. The three most significant threats over the last several decades are:

Milkweed habitat loss in the U.S. and Canada, (monarchs eggs and caterpillars are dependent on the milkweed plant). The primary causes for milkweed loss are urbanization and industrialized, large-scale farms (eliminating the borders between smaller farms) and the widespread use of herbicides and herbicide resistant crops;

A history of illegal logging in the Mexican mountain sanctuaries that – while drastically reduced by the combined efforts of the current Federal and state governments and major conservation organizations in Mexico in the last 6 years – caused significant forest cover loss over the previous decades, and these efforts must be maintained. It is hoped that further education, reforestation and continued monitoring, will continue to improve this devastating practice (the monarchs are dependent on the evergreen trees that shade out some of the sunlight that would make them overactive and they also provide vital roosting space for collective rest, warmth and protection for the overwintering monarchs that go into a state of semi–dormancy); and

Climate change, causing, in the last decade, more freakish, violent storms that are killing hundreds of millions of butterflies in the sanctuaries due to the deadly combination of both cold and wet.

Independent studies from Fondo Mexicano para la Conservación de la Naturaleza (FMCN) show promising signs of a dramatic decrease in illegal logging. While reforestation of these protected areas remain a major challenge and a long-term goal, SK Films cares about the future of these remarkable creatures and is donating a significant share of the film’s revenue to FMCN towards monarch conservation efforts. is a fundraising tool and a joint effort between the FMCN and the Flight of the Butterflies in 3D project to help bring awareness and funding to the following areas:

  • Environmental education
  • Ecotechnology & green living
  • Restoration of degraded areas, from illegal logging, forest fires etc.
  • Forest fire protection and management
  • Local community promotion and involvement
  • Development of leadership roles with the support of the Monarch Network

In 2008, UNESCO declared the Monarch Butterfly Biosphere in Mexico, a World Heritage Site.

FMCN participates as the principal partner for conservation and the liaison with the Mexican public and specialized conservation organizations with the technical capacity to implement concrete conservation and social development actions in the Monarch region, chiefly in the about 56,259 hectares of the Monarch Butterfly Biosphere Reserve.

There is much that the average citizen can do to plant milkweed and engage in conservation activities and to lobby governments to do more to protect the monarchs. Three Man-Made threats to the monarch migration include:

1. Milkweed habitat loss is the biggest short term threat to the monarchs migration, as they are totally dependent on milkweed for laying their eggs. It is also the only food source for caterpillars, as well as providing a nectar source for adults. There are several things occurring that are causing significant milkweed loss and why it is so important to plant milkweed. Firstly, the milkweed grows naturally along the borders between farms and fields, but as farms become larger due to more industrialized farming, those borders disappear and the milkweed is permanently cut down. Secondly, significantly more genetically modified seeds are being used, especially for the major crops of corn and soybean. These plants, often referred to as “Roundup® Ready” crops are herbicide resistant, but the surrounding milkweed is not and dies off permanently in these herbicide sprayings;

man made threats 1 Conservation & Preservation
A farmer using a thresher on his field

2. Long term degradation of the wintering habitat in the sanctuaries, mainly due to illegal logging;

man made threats 2 Conservation & Preservation
An aerial shot of one of the mountain sanctuaries where the Monarchs travel for the winter. Loggers are dangerously close to this site.

3. Climate change, which is causing more out-of-season storms and an unusual combination of severe temperature drops and excessive rain.

man made threats 3 Conservation & Preservation
A forest after severe thunderstorm, high winds and rain activity. Photo courtesy of Journey North.

WWF’s January 2014 report from Mexico shows that the number of Monarch butterflies wintering there has dropped by 44% from the same time last year.

This is a staggering loss. The lowest in recorded history.

The number is measured by the amount of forest they occupy, and this year the number of butterfly acres has decreased to 1.65 acres. Only three years earlier, the numbers were at 9.93 acres. A catastrophic drop in such a short time period.

The Mexican government has made logging near the sanctuaries illegal, but enforcement is difficult in such remote regions. In 2008, UNESCO declared the Monarch butterfly reserve in Mexico a World Heritage Site. The World Wildlife Fund has classified the Monarch as “Near Threatened”, which means they are likely to qualify for threatened status in the near future.

While there is much that is now being undertaken and completed by the Mexican, Canadian and U.S. governments, the three countries along the monarchs’ North American migratory routes, much still remains to be done. The concern of climate change is a global concern and caused by a variety of factors. It is one that many people are lobbying to change for many reasons due to the environmental impact on ecosystems, including this one. The illegal logging issue has been greatly reduced over the last few years and is a continued effort to stop this highly negative practice. Local residents who can earn much from cutting the trees in the sanctuaries are being educated about sustainable development, the importance of this natural wonder of the world and the impact of eco-tourism to their local economy. There is much that the average citizen can do.

There are four major conservation organizations dedicated to monarch butterfly conservation and education, three in the U.S. and one in Mexico that are listed in our film and provided as resources on this site. You can get involved and support these organizations or you can do something as simple as planting milkweed at home and in your community to help the monarch butterfly migration.

How to help

One of the easiest and most beautiful ways to help sustain the Monarch population is to plant a milkweed garden in areas that lie along the migratory route.

Learn how to create a butterfly garden >

Natural Predators

Even though the Monarch is a highly evolved migratory insect with specialized body parts to help it migrate long distances, it remains a living creature, susceptible to death from a variety of natural causes. Even a few drops of rain can be dangerous to a Monarch, as it weighs down its wings, impeding flight. Wet wings in cold or freezing temperatures are almost certainly fatal, and the reason butterflies overwinter in warmer climates like Mexico.

Like most other insects and animals, the Monarch butterfly faces natural predators. Over 99% of Monarch butterfly eggs and caterpillars do not escape from natural predators, which is why so many eggs are laid in the first place. These predators are different during each stage in the butterfly’s life cycle. Eggs and caterpillars are easy targets for ladybugs. Ants, spiders and wasps attack caterpillars and are immune to the milkweed poison.

For the Monarchs who make it to adulthood and survive the long migration south, they must face three more enemies while they rest at the overwintering site in Mexico – two birds species and a mouse:

Black Backed Orioles

natural predators 1 Black Backed Orioles Conservation & Preservation
Photo courtesy of Journey North.

Black Headed Grosbeaks

natural predators 2 Black Headed Grosbeaks Conservation & Preservation
Photo courtesy of Journey North.

Black-eared Mouse

blackearedmouse Conservation & Preservation

Since there are millions of butterflies roosting on trees, they are vulnerable to the birds, who hunt in the morning and afternoon. The birds eat more males than females – this is due to female butterflies having more of the milkweed toxins in their systems. Once the sun goes down, the danger remains. Mice feed at night on any butterflies that rest on the forest floor. Another growing threat is the fire ant. It’s a Monarch predator immune to milkweed poison – and their numbers and range are vastly increasing. Climate change is allowing the ants to move farther north in the U.S., and their destructive impact on the butterflies is developing at an alarming rate.

natural predators 4 Conservation & Preservation

An easy and beautiful way to combat the negative effects of Monarch predators is to plant a milkweed garden in areas that lie along the migratory route. Providing butterflies with a safe breeding ground is one thing we can do to help increase their numbers.

Learn how to create a butterfly garden >

The Importance of Milkweed

While many farmers and developers view it as just a weed, Monarch butterflies depend on milkweed to survive. In fact, these are the plants on which they lay their eggs and are the only food source for the caterpillars. Without milkweed, Monarchs would not be able to produce the successive spring and summer generations that result in their magnificent fall migrations. It takes two generations, the butterflies returning from Mexico and their offspring, to reoccupy the summer breeding areas. These are then followed by one or two more generations of 3-5 weeks, with the last becoming the long-lived migratory generation who make the epic journey south to Mexico.

This super generation lives up to 8 times longer than the previous generations. Long life requires energy conservation and these Monarchs neither mate nor lay eggs on their migration, but they do like to catch free rides – the trip to Mexico is one of gliding and soaring rather than of rapid flight. Every day the monarchs stop to feed on nectar from numerous fall flowers, such as goldenrods, sunflowers and frost weed in Texas, to fuel their flight. Some of the sugar-rich nectars from the flowers are converted to fat and it’s the breakdown of these fats into sugars that allows Monarchs to survive 4-5 months at the overwintering sites.

Our film follows the annual cycle of the eastern Monarch population. It’s an incredible journey that begins in late summer in Canada and the northern United States. In August, the Monarchs begin to migrate, reaching the overwintering sites in October, a journey of 2-2.5 months. In Mexico, the Monarchs overwinter in the oyamel evergreen forests, forming large clusters on these trees. Toward the end of winter, from February to April, they leave the overwintering locations. The Monarchs feed, mate, and lay eggs on milkweeds as they move north. The successive spring and summer generations lead to yet another wondrous fall migration.

There are over 100 different milkweed species. Monarchs use about 30 and you’ll see some of them in Flight of the Butterflies in 3D: common milkweed in the Southern Canada scenes, antelope horn milkweed and a butterfly milkweed (a.k.a “butterfly weed”) in the Texas scenes.

Threats to Milkweed

The loss of milkweeds and therefore butterfly habitats, is occurring rapidly.

Industrialized farming is a major contributor to milkweed loss. The amalgamation of various acres of farmland means milkweed is pulled out in areas surrounding the farms, decreasing the areas where butterflies can stop to lay eggs and where the caterpillars can grow into butterflies.

Genetic seeds, also known as “Roundup® ready” crops are immune to herbicide. This means when they are sprayed, they survive. Milkweed, however, is not Roundup® ready and is killed off during this process.

On the flip side of industrial farming is reduced farming. As farmland is procured for other, commercial uses, the milkweed again suffers from habitat loss.

How to help the Butterflies and their Migration

Conservation groups such as Monarch Watch, Journey North, and Monarchs in the Classroom urge gardeners, landowners and agencies to plant milkweeds and to protect existing milkweed habitat. It’s an easy and beautiful solution to the problem. See the map below for the type of milkweed that is best to plant in your region.

milkweed maps Conservation & Preservation
Milkweed map, images and information courtesy of and © Monarch Watch.

Northeast Region (and Southern Canada)

milkweed 1 Conservation & Preservation

Common Milkweed

Flowers: dull purplish-pink to greenish white
Habitat: Prairie, pastures, roadsides, and waste ground; sandy, clayey, or rocky calcareous soils of banks or flood plains

milkweed 2 Conservation & Preservation

Swamp Milkweed

Flowers: bright pink or, rarely, white
Habitat: Banks and flood plains of lakes, ponds, and waterways, marshes, swamps, and other wet areas of prairies

milkweed 3 Conservation & Preservation

Butterfly Milkweed (a.k.a. Butterfly Weed)

Flowers: bright orange, rarely red or yellow
Habitat: Sandy, loamy, or rocky calcareous soils of prairies, roadsides, & waste places

milkweed 5 Conservation & Preservation

Poke Milkweed

Flower: Umbels weep down with each flower on a long pedicel. Color is white with lavender to green tinges. Stems of the umbels are a purplish color. Horns protrude through the hoods. Corolla reflexes backward. Corolla, hoods, and horns are a light pink color.
Habitat: Shores, woodlands, and woodland edges.

For further information on milkweed in Ontario, Canada please visit the
Ontario Ministry of Agriculture, Food and Rural Affairs

South Central Region

milkweed 6 Conservation & Preservation

Antelope Horn/Green Antelope Horn Milkweed

Flowers: Inflorescences solitary and terminal, usually very crowded, flowers rather large, pale yellowish green sometimes tinged with purple.
Habitat: Flats and desert swales, sandy and rocky hillsides, with pinyon, juniper, oak, mesquite, Yucca, and Nolina

milkweed 7 Conservation & Preservation

Zizotes Milkweed

Flowers: Green with a purple tinges. Erect umbels, Corolla reflexes backwards. Horns protrude through the hoods. Corolla is a lighter shade of green compared to the hoods.
Habitat: Grows in sandy, rocky ground conditions, prairies, ditches and fields.

milkweed 8 Conservation & Preservation

Tropical Milkweed

Tropical Milkweed grows in Mexico, and along the Gulf Coast. It is often planted in gardens/butterfly gardens for its attractive appearance. However, this is not the kind of milkweed monarch’s need to survive.

milkweed 9 Conservation & Preservation

Spider Milkweed

Flower: greenish-white and reddish-purple
Habitat: Sandy or rocky soils in prairies. This is the second most important milkweed for Monarchs, as it’s the major host for returning butterflies in Texas, Oklahoma and Kansas.

Southeast Region

milkweed 10 Conservation & Preservation

Aquatic Milkweed

Flowers: Corollas, hoods, and horns are usually white or light pink. Horns protrude through the hoods. Corolla reflexes backward.
Habitat: Hydrated soils, floodplains, water way margins, marshes, cypress swamps, ditches, and wet lands.

milkweed 11 Conservation & Preservation

White Milkweed

Flowers: Inflorescences usually solitary and terminal, flowers white, rather large and showy, snowball like in appearance.
Habitat: Thickets and open woods, usually in sandy or rocky soil

milkweed 12 Conservation & Preservation

Butterfly Milkweed (a.k.a. Butterfly Weed)

Flowers: bright orange, rarely red or yellow
Habitat: Sandy, loamy, or rocky calcareous soils of prairies, roadsides, & waste places

West Region

milkweed 13 Conservation & Preservation

Showy Milkweed

Flowers: purplish-rose
Habitat: Sandy, loamy, or rocky soils on banks and flood plains of lakes, ponds, or waterways or moist areas in prairies

milkweed 14 Conservation & Preservation

Antelope Horn Milkweed

(western biotype – only in AZ, NM and NV)
Flowers: Inflorescences solitary and terminal, usually very crowded, flowers rather large, pale yellowish green sometimes tinged with purple
Habitat: Flats and desert swales, sandy and rocky hillsides, with pinyon, juniper, oak, mesquite, Yucca, and Nolina

How to help

You can help keep milkweed – and the Monarch butterflies – alive by planting a milkweed garden in areas that lie along the migratory route. It’s an easy and beautiful solution to the problem.

Learn how to create a butterfly garden >

 Conservation & Preservation
did you know spot Conservation & Preservation
get invovled create your own butterfly garden spot Conservation & Preservation