Parks Canada: National Parks and National Historic Sites

Monarchs prepare for takeoff at the tip of the park — after the author headed home.

Photo: Ethan Meleg

Life Cycle: Monarch butterfly

Video: Monarch caterpillar forming its chrysalis

Video: Adult Monarch butterfly emerges

Range Map: The Monarch butterfy

Egg
Female monarchs lay their eggs on the underside of milkweed leaves. They’re careful to lay only one per plant, since the young larva’s voracious appetite leads it to eat any un-hatched eggs in its path. Depending on how warm or cool the weather is, after three to eight days the egg hatches and the larva emerges, feeding on its egg shell before consuming the milkweed leaf.

Caterpillar
Unlike most caterpillars, monarchs don’t blend in with their surroundings. Instead, they have bold yellow, black and white stripes to warn predators to stay away. The bitter milkweed leaves are poisonous. As the larvae eats them these toxins build up in its body.

Chrysalis
The monarch spends about eight to 12 days as a caterpillar and sheds its skin as it goes through five larval stages. When it’s ready to molt for the last time, the caterpillar attaches itself to a twig and sheds its skin to form a hard protective chrysalis. Within 12 to 14 days, the chrysalis becomes translucent and the butterfly is ready to stretch its wings.

Adult
You can tell male and female butterflies apart by their wing patterns. Males have two black spots on their hind wings, while females have slightly wider wing veins. By using their antennae to measure the direction of the sun, each monarch knows when and which way to migrate.

Habitats/Behaviours
Monarchs have the largest and longest insect migration in North America. Some adult butterflies will travel thousands of kilometres during their short lifespan. However, it takes four generations to complete the round-trip from southern Canada to northern Mexico and back. Offspring of monarchs that overwinter in northern Mexico migrate northward in late spring, laying their eggs along the way. The second and third generations then reproduce, but only adults born in late summer migrate to central Mexico to spend the winter.

Monarchs are able to fly great distances by knowing how to conserve their energy. During migration, they ride rising columns of warm air and take advantage of strong winds to help speed their flight.

Range
Different monarch species are found throughout the world. In Canada, their natural habitat includes southern Alberta, Saskatchewan, Manitoba, Ontario, Quebec and the Maritimes. Yet, monarchs have also been seen as far north as James Bay.

Photo Club Field Report
Read an interview with photographer Tobi Asmoucha to find out how to capture the best side of a monarch.

Heritage Treasures of Parks Canada Photo Contest
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National Park Memories Contest
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Best of the Bruce Photo Contest
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