Monday, February 22, 2021

The Iconic Monarch Butterfly 

monarch caterpillarMany are familiar with the monarch butterfly, but did you know these important pollinators are in trouble? Over the past 20 years, the number of monarchs in North America has declined by over 90 percent! Loss of breeding and overwintering habitat, increased pesticide use, and climate change are some of the risks monarchs face. The U.S. Fish and Wildlife Service recently announced that listing the monarch as an endangered or threatened species was “warranted but precluded,” meaning there are other species in greater trouble that need to be listed first.

Every fall, millions of monarchs across the northeast begin a journey to their wintering grounds in Mexico—a migration of up to 3,000 miles! However, don’t expect to see the same butterflies return to your backyard next year. You’re more likely to see their great-grandchildren or great-great-grandchildren. Every year, there are four generations of monarchs. When the fall migrants leave the wintering areas and head north in the spring, they will stop and breed as soon as they reach areas with milkweed—the only plant the monarch caterpillar eats—long before reaching the Northeast. The next two generations will continue to move north as the monarchs settle into their summer range. The fourth generation becomes the new fall migrants, starting the cycle over again.

Ways you can help:

Fun Fact: Monarchs are able to store toxins from the milkweed they eat as caterpillars. These toxins, called cardenolides, make them very distasteful to predators!

Photo of monarch caterpillar by Sandy Van Vranken.

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Information attributed to NYSDEC is taken from press releases and news announcements from New York State's Department of Environmental Conservation.

4 Responses

  1. It’s good to remind people what’s happening with monarchs, an iconic and much loved species. In addition to Monarch Joint Venture, two other valuable organizations and sources of information are Monarch Watch ( and Monarch Butterfly Fund ( One small correction. As stated in the note, the monarchs that emerge from overwintering in Mexico return to Texas and other southern states where they lay eggs, and the next generation (from these eggs) continues the return migration into the full breeding region. But that’s the end of migration (directional movement); the next generation or two simply spread out into open regions with milkweed (that is, dispersal, not migration). Glad to have a note on monarchs.

  2. Noel A. Sherry says:

    Thought of you, Ernest, when I saw this article, and so much appreciated your taking us Twitchell Lakers on field trips to check up on the Monarch colony along our Twitchell Inn Road. That sensitized me to this amazing butterfly and its long winter and spring flights to and from our Lake.

  3. nathan says:

    The milk weed that monarchs depend on as a larvae food source has become much more rare with farmers using glyphosphate herbicides for genetically modified corn crops. Milkweed only grows wel in disturbed dirt areas, meaning its been plowed or dug up in some way in recent years. most milk weed grew along edges of corn fields, now it does not and this has decimated manarch butterfly breeding sites. If you own some yard, dig a small area of semi shade soil and speread some milk weed seeds on soil and rake. creating a milk weed patch for larval food. I maintain an acre of milk weed on the north side of some pine trees and i get hundreds of monarch catapillers every year. while i have 1/4 acre in full sun and get only a few larvae. i think the sunny area gets too hot in full sun. But i enjoy seeing the monarchs and feel thatim doing a small part to save a species. BTW the milkweed patchs i save seeds when pods are brown, i brush hog patch and it regrows for a few years, then i rototill every 2-3 years in early spring spread seeds (store in freezer for winter) and rake over. want help with patch of millkweed post response to my article

  4. ADKBfly says:

    ADK Action is holding a native plant sale to help homeowners get pollinator-friendly plants. To pre-order plants, go to

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