By Marlys Hagstrom of Hutchinson
I sat on the front steps of our house enjoying the warmth of the August sun. As I shielded my eyes from the glare, I noticed the sky darkening. I wondered what was happening. In a matter of a few minutes, hundreds of orange and black butterflies alighted in the trees of our yard. One delicate creature landed on the step by my feet. I studied it closely as it rested and spread its beautiful wings. How long had it been flying? Where had it been? The flight of the monarch is one of the most intriguing mysteries in our world today.
Once found only in North America, flocks of monarchs will fly together from the south in the Sierra Madres Mountains of Mexico, to the north into states such as Minnesota and into Canada. Guided by instinct, they migrate in the same patterns year after year. The monarch looks fragile but is a very complex creature. The name “monarch” means king or ruler. Characterized by strong wings, brilliant colors, and unique behavior, the monarch’s body structure is complex. It has six jointed legs and waterproof skin. Two pairs of curved wings look delicate but are very sturdy. Their antennae can feel, smell, taste, and sense direction. While the human eye has a single lens, the monarch has thousands of lenses. They can see other monarchs, sense danger and find food. The stomach holds the female eggs until laid. A hard body protects the organs inside. No framework of bones exist, only a shell made of chitin. The primary source of food for the monarch is the leaf of the milkweed plant. Milkweed also provides protection. The leaves contain a poison that is absorbed into the caterpillar’s body and later into the butterfly’s body to protect it against predators like birds.
As females fly north from the Sierra Madres, they head for areas of flowers, grassy fields, and gardens. They look for milkweed where they lay their eggs on the underside of the leaf. Females can lay up to four hundred eggs in their lifetime. However, only a small number ever grow into adult butterflies. Millions may start their long journey, but many will die along the way. They fly all year long in warmer climates covering long distances as far as two thousand miles in one day. When feeding or traveling, they glide, floating with wings spread out. Then they will fly faster or “power fly” and glide again, carried by the breezes; Monarchs rest by night and fly by day. The energy stored up during the winter hibernation is spent as they travel in search of the milkweed plant.
The 30- to 40-day life cycle begins when the eggs are laid and attach themselves to the milkweed leaf. The monarch changes four times as it grows from egg, caterpillar, chrysalis and finally into the adult butterfly. The entire process is called metamorphosis. The green and black striped caterpillar has a short life spent feeding on a milkweed plant. It eats to store fat for energy in spinning the chrysalis. As the life cycle nears completion, a vibrant black and orange butterfly emerges from the shimmering green chrysalis. Adult butterflies do not bite or chew but use long, thin proboscis (drinking tube) to drink nectar from flowers. Tiny tasters on the monarch’s feet pick up the sweetness of the flower. Another important role in nature is pollinating or fertilizing flowers. Pollen sticks to their body and then falls onto other flowers when they land upon them for feeding. In late summer, monarchs choose trees such as willow or maples to rest upon as they prepare to journey south for the winter.
The long trip finds the rays of the sun bleaching the colors in their wings while the winds tatter the delicate wings. Some monarchs have been tagged to help scientists learn how they navigate the long distance from their summer to winter home. Some of those tagged in Minnesota have been found in Mexico.
While herbicides present a danger by killing the milkweed plant, real estate developments and the depletion of forests endanger navigation routes to summer habitats. Tourists traveling to winter home sites stir up the hibernating monarchs. Sanctuaries are being established to protect one of our most puzzling mysteries. The monarch has intrigued generations of people from North America to Asia and Europe. With the help of the scientific community, we can all look forward to the flight of the monarch.