Monarch Butterflies

The Monarch Butterfly is probably the most well-known butterfly in North America, and we’ve had quite a few Monarchs visiting the farm over the last month. A recent question about how to attract Monarchs to your garden got us thinking that other gardeners would probably love to have that information as well. So this week’s blog post is all about Monarchs, and what you can do to make your property Monarch-friendly!

A Monarch sips on nectar from Swamp milkweed on the farm

 

About Monarchs

Monarch butterflies are bright orange with heavy black veins and wide black borders containing two rows of white spots, and have a wingspan of 7 to 10 centimeters. Caterpillars are striped yellow, black, and white, and are 5 cm long. Chrysalises are gold-green and can typically be found hanging from a milkweed leaf or branch.

The Eastern population of Monarchs, which summer east of the Rockies, migrate 5 000 kilometers every fall to spend October through March in their wintering sites around the mountain forests of Mexico. It’s the longest migration of any butterfly, and one of the world’s longest insect migrations.

 

Photo: United States Department of Agriculture

 

They are picky eaters

In their caterpillar stage, the monarch’s sole source of food is the milkweed plant. Monarchs lay their eggs on milkweed plants so the caterpillar can begin to feed right away. The caterpillars have evolved the ability to store toxins known as cardenolides, obtained from their milkweed diet, specifically to make themselves poisonous to birds.

Once they emerge as adults, they can start sipping nectar from a variety of native flowers, however, they still remain poisonous to predators. Some favourite flowers include: echinacea, black-eyed susan, sage, goldenrod, zinnias and dahlias.

They’re endangered

The Eastern Monarch population was recently assessed as Endangered by the Committee on the Status of Endangered Wildlife in Canada. This population was estimated to be over a billion in the late 90’s, but declined to approximately  200 million by 2015 – 2016. This decline has been attributed to deforestation of both their winter habitat in Mexico, and their summer habitat here, as well as loss of milkweed and nectar plants. A storm in March 2016 killed a large number of monarchs at Mexico’s winter sites, further reducing their already declining population. 

What you can do

There are some very simple steps you can take to make your property butterfly-friendly!

Plant milkweed:

Common milkweed (Asclepias syriaca) – grows in well-drained soil, but may spread easily. 

Swamp milkweed (Asclepias incarnata) – grows in damper, marshy areas, and does not spread as easily as Common milkweed. Another Nova Scotian non-profit, the Mersey Tobeatic Research Institute, has a butterfly club you can join here which includes a swamp milkweed plant and/or seeds. 

You can also plant other beautiful butterfly-friendly flowers such as: Purple coneflower, Black-eyed susan, Canada goldenrod, Zinnia, and Sage. These, as well as other butterfly-friendly flowers, are available at most nurseries. 

Black-eyed Susans and Zinnia on the farm, and wild Canada Goldenrod

 

 

References

Giller, G. (2015). Butterflies Weaponize Milkweed Toxins. Retrieved from https://www.the-scientist.com/daily-news/butterflies-weaponize-milkweed-toxins-34546

National Geographic. (n.d.). Monarch Butterfly. Retrieved from 
https://www.nationalgeographic.com/animals/invertebrates/m/monarch-butterfly/

Nature Conservancy of Canada. (n.d.). Monarch. Retrieved from http://www.natureconservancy.ca/en/what-we-do/resource-centre/featured-species/insects-and-spiders/monarch.html

World Wildlife Fund. (n.d.). Monarch Butterfly. Retrieved from http://www.wwf.ca/conservation/species/monarch_butterfly/