September 2016: Monarch Caterpillars at Reed Creek!
These Monarch Caterpillars have been busy chomping away at our Milkweed Plants!
A female monarch butterfly, that was on her way down to Mexico for overwintering, stopped by the park in the last couple of weeks and laid eggs on our milkweed plants. Female monarch butterflies lay their eggs on milkweed leaves because their larvae (caterpillars) are specialist who only eat milkweed. The milkweed plant is a perennial known for the milky sap contained in the leaves. The milky sap is toxic to vertebrate herbivores if ingested due to the cardenolide alkaloids contained in the leaves and stems. When Monarch larvae ingest milkweed, they also ingest the plants' toxins, called cardiac glycosides. They sequester these compounds in their wings and exoskeletons, making the larvae and adults toxic to many potential predators. Vertebrate predators may avoid Monarchs because they learn that the larvae and adults taste bad and/or make them vomit.
Most Monarch butterflies will only survive 3-6 weeks. During that time their primary goal is to reproduce. Each fall Monarch butterflies cannot survive a long cold winter therefore each fall they migrate to a warmer spot to spend the winter in a special roosting habitat high in the mountains of Mexico. Monarchs of North America are special, they are the only butterflies to make such a long, two way migration every year. Amazingly, they fly in masses to the same winter roosts, often to the exact same trees. This is type of migration is usually seen in other animals like whales or birds, but unlike those animals, who will each make a long migratory journey, it take several generations of monarchs to complete the migration each Fall.
The caterpillars in the garden at Reed Creek are the special migratory generation, who will fly 2,013 miles from Reed Creek to Michoacán Mexico to overwinter in the special tree-top forest there. In the spring, those same Monarchs will return next spring to mate and will die soon after. This special migratory generation will live 8 months compared to the normal life span of other generations of monarch, which is only 3-6 weeks. The caterpillars we have will change into their pupa form (chrysalis) in the next few days. They will continue their amazing transformation and after two weeks they will emerge as beautiful monarch butterflies and begin their long trip to Mexico.
For more information check out these fantastic sites:
MONARCH UPDATE: October 6, 2016
Our monarch caterpillars have completed their lifecycle and emerged as Monarch Butterflies. They will soon be on the way to Mexico for the winter. Here are some pictures of their complete lifecycle at the park:
Monarch Caterpillar pupal form also known as a chrysalis. The gold colored holes are called spiracles. These allow for the pupa to breath.
The remaining chrysalis right after the Monarch Butterfly has emerged. The act of emerging is also called eclosion.
The recently eclosed Monarch Butterfly drying its wings in the sunlight in preparation for the long journey to Mexico.