Hello my faithful readers,
I just got back from a fun filled weekend in Bruce Peninsula where we were trying to capture monarchs with the Escarpment Biosphere Conservancy. Unfortunately the Queen narrowly avoided escape but we did manage to catch about 40 monarch butterflies. Our goal was to tag their wings with a small sticker which would help researchers track the monarch migration. The tagged and released butterflies are currently on their southwardly migration towards Mexico. Despite their iconic status, I knew relatively little about these royal butterflies. I’d like to share with you all some of the most interesting features of monarchs.
The monarch lifecycle begins with miniscule eggs which are laid by the previous generation exclusively on the underside of milkweed leaves. After 3-6 days, tiny caterpillars emerge and quickly devour their nutrient rich egg casing. Over the next 17 days or so, the caterpillar eats the toxic leaves of milkweed plants and becomes toxic itself. As the caterpillar grows it must shed its exoskeleton which does not grow with it. After shedding five times, the caterpillar is fully grown and is ready for its final molt. The final molt reveals a beautiful chrysalis which will act as a changing room for the caterpillar as it transforms into an adult butterfly. After approximately 8 days, the butterfly begins to emerge from the chrysalis. At first, its wings are diminutive, but as hemolymph (blood) flows into the wings, they expand to their normal size. The monarch is now fully matured and ready to venture forth into the world, taking flight on its brand new wings.
As if the metamorphosis from caterpillar to butterfly wasn’t interesting enough, monarchs also make one of the longest migrations in the animal kingdom. Monarchs spend their winters on vacation in a small area to the west of Mexico City. In early spring, monarchs begin their migration by travelling in a northeasterly direction. As they migrate they feed on the nectar of flowers and lay over 300 eggs per adult on the underside of milkweed plants. Shortly after doing so the adult butterfly dies and the next generation continues the migration. This cycle repeats itself for the rest of the migration with at least three generations of monarchs living and dying during the journey. During late summer or early fall the migratory generation of monarchs at the northern edge of their range emerges and begins their southward migration back to Mexico. But these aren’t ordinary monarchs, this super generation of monarchs has a lifespan that is almost 10 times longer than ordinary monarchs. They forego reproduction so they can put all their energy into making the long journey to Mexico’s more hospitable climate in a single generation.
These monarch butterflies are truly remarkable insects, but unfortunately their numbers are declining. The good news is that we can all help the monarchs. As you may have deduced from the preceding paragraphs, milkweed is an incredibly important plant for monarchs. Growing milkweed in your garden is easy, fun, and best of all it provides monarchs with habitat for laying eggs and food for caterpillars. Another thing you can do to help out monarchs is plant a butterfly garden which will provide the adult monarchs with the nectar they eat. As an aesthetic bonus, you get to enjoy a beautifully coloured garden with monarchs as dinner guests.
Thanks for reading,