Autumnal miracle


The Monarchs are back.

The Monarch butterfly is colored orange and black, which is appropriate since it begins to arrive at the Pismo State Beach grove around Halloween. By Thanksgiving, the winter population has settled into the high, sheltering trees along Highway One just south of Pismo Beach.

There, they’ll spend the winter clinging to each other in large clusters for warmth on our cold nights until late February.

There are two general populations of Monarch butterflies in the United States. The group living east of the Rocky Mountains migrates south to spend the winter in Mexico. Those living west of the Rockies migrate to the coast of central and southern California.

The western Monarchs’ summer range extends from the Rockies to the Pacific Ocean and as far north as southern Canada. In October, as colder weather approaches, the butterflies know instinctively they must fly south to survive. Some migrate over a thousand miles. Many never make it.

Pismo State Beach is host to one of the largest winter congregations, varying in number from 20,000 to 200,000. There was fear in 2002—3 that genetically-altered crops were affecting the Monarchs when the grove count in Pismo dropped from 60,000 to 30,000.

However, in 2003—4, the numbers climbed again to 56,000.

Professor Dennis Frey of Cal Poly San Luis Obispo conducts the annual count locally. He and his crew of volunteers cut down a typical cluster of Monarchs and count them. They then multiply that number by the number of clusters to arrive at their estimate. This year looks to be a good one for the orange and black wonders.

There are other groves located from the San Francisco area as far south as San Diego. The winter Monarchs live about six to eight months. On sunny winter days, they flap their wings until they’re warm enough to go foraging for nourishment in flower nectar. Since I live less than a mile from the grove, they visit my flowers and potato vine bush, bringing additional color to the winter months. In late February, as the weather warms, there is a flurry of mating in the grove. Then the females fly north seeking milkweed plants where they must lay their eggs. That job accomplished, the winter (female) Monarchs die. The males, left behind at the grove, also die off by spring.

The eggs, however, hatch after a few days; and the tiny larvae begin to eat milkweed leaves day and night. Milkweed is the only food the larva can eat, but it eats enough to increase its weight 2,700 times in two weeks! That’s the equivalent of a human baby growing to the size of a gray whale in just fourteen days!

Once it’s eaten its fill, the now full- grown caterpillar attaches itself to something solid, sheds its skin, and forms a hard, green and gold outer skin called a chrysalis. Within it, the caterpillar rearranges its body’s molecules and then emerges as a beautiful Monarch butterfly.

The new summer Monarchs continue to fly farther north, following the milkweed, mating, laying eggs, and dying. Each generation lives only about six to eight weeks. This process is repeated four or five times during the summer.

Then, with the shortening days of October, the new winter generation of Monarchs starts south. They do not mate but fly directly to their wintering spots.

And that’s the miracle. How do they know where to go? How does one generation of

Monarchs pass the information to another? No one knows – though scientists have tried hard to find out.

All anyone really knows is that the Monarchs show up in late October on the Pacific Coast where they delight us for the next four months. Thus, the return of the Monarchs is a kind of miracle.

And I live right in the middle of it!