Monarch Migration Is On! Update 10/1/2013

Monarch butterfly. Photo credit Armon Wikipedia Commons. CC BY-SA

Monarch butterfly. Photo credit Armon Wikipedia Commons. CC BY-SA

MONARCHS IN PERIL: Three scientists and naturalist sit in on the Diane Rehm Show (NPR) to discuss banding monarchs, migration, population declines and  steps to turn the situation around. Listen in

Monarch butterflies are on the move ! From Maine to Manitoba, monarchs  (Danaus plexippus) are starting their migration  south and west toward Mexico, to the oyamel fir forests of Central Mexic where they will cover the trees and overwinter.

On their trip back, they’ll land in Texas, seek out milkweeds and lay eggs. Their job is done! It is the next generation — larvae emerge, become caterpillars, molt, enter a pupa phase, and form a butterfly inside the chrysalis – that travels northward in the spring.

Check below for a Google earth tour and podcast of  the monarch’s world

If there is a charismatic species in the insect world, it is the monarch butterfly, whose plight seems to grow worse year by year. What’s the hitch?

Réserve de biosphère du papillon monarque

Monarch Biosphere Reserve. Says monarch expert Lincoln Brower: “Industrialized herbicide-based agriculture is destroying the flora in the Midwestern United States that monarchs depend on in the spring and summer.”

Monarchs are in crisis – as are other species – from multiple factors that jeopardize their migratory process across several seasons. First, weather plays a role. Wetter winters and colder winters make them vulnerable (soggy wings, too cold to survive). Then there is drought (which can vary) in places like Kansas, Oklahoma, Texas and Mexico when they are migrating south. (They need water and nectar plants.)

Another factor is today’s farmland in the Midwest (and elsewhere)  and the disappearing habitat that provides returning monarchs with welcoming milkweed – the host plant —  when they lay eggs that will journey north as young, full-fledged butterflies. Hedgerows (small strips of farmland with rogue trees, grasses and wild plants) are disappearing from the agricultural landscape.  (They also provide habitat for birds!) Soils are treated to eliminate weeds and land is planted with genetically modified crops that are  RoundUp Ready.

There is still illegal forestry in the part of Mexico – a remote place only discovered in the late 1970’s — where the butterflies overwinter. NEW! CBS News story 

“The migratory biology of the monarch is a phenomenon, said Lincoln Brower, professor of Biology at Sweet Briar College, who has studied them for decades. “It’s an endangered biological phenomenon.” (Washington Post interview, 2011)

New York Times Reporter Michael Wines provides a more ominous report from the 2012-13 winter census: ” The number of monarch butterflies that completed an annual migration to their winter home in a Mexican forest sank this year [2012-13] to its lowest level in at least two decades…. The area of forest occupied by the butterflies, once as high at 50 acres, dwindled to 2.94 acres in the annual census conducted in December[2012]…..”

Danaus plexippus on a coneflower

Danaus plexippus on a coneflower. Photograph taken at Tyler Arboretum (Pennsylvania)

What separates a species from being endangered or having its entire migratory biological process endangered ? Very little.

What can you do ? Check the list and resources below

  • Learn the flyway routes (latitudes)  and be prepared. Check the latitude schedule  at MonarchWatch to see when you may expect an onslaught.
  • Attend a monarch banding event to watch experts.
  • Provide water. Yes they do drink it.  On a trip to Venezuela’s Canaima National Park, I watched a cloud of sulphur butterflies descend on a wet rock to take water (and salts)
  • Supply nectar by adding flowering native shrubs (and nonnatives like butterfly bush) , perennials and annual flowers in your yard and neighborhood/community spaces. New! Butterfly haven how-to article Adrian Higgins, Washington Post
  • Plant milkweed and plenty of it. Dr. Chip Taylor noted in a 2011 Washington Post interview, “ …[M]ilkweed has disappeared from at least 100 million acres of [Roundup Ready] row crops….Your milkweed is basically gone.”  The weed-free farm is the gold standard, says May Berenbaum, who heads entomology at the University of Illinois. One study found  milkweed on only 8% of corn and soybean fields, down from 51% just ten years before.
  • Public spaces  need to add natural habitat– whether small planted islands in parking lots or mini-parks with native flowering plants, even if it’s micro-amounts for butterflies and birds. Ask Walmart, Costco and your shopping malls to do their bit.
  • Ask your parks department to add milkweed and butterfly-friendly natives to their spring and summer plantings.

Resources and Information

Latitude schedule for trip south from MonarchWatch

Butterfly migration Google Earth Tour at the Monarch Biosphere Reserve and Podcast of the spring migration. Mexican geographer Isabel Ramírez and American biologist Karen Oberhauser are working to save monarch habitat on both ends of the 2,500-mile journey. (Google Earth Tour was produced by American Public Media in cooperation with the Encyclopedia of Life Learning + Education group.)

Winter of the Monarch, New York Times OpEd by Lincoln Brower and Homer Aridjis (March 15 2013)

Monarch Census story by Michael Wines New York Times (March 14 2013)

Monarch Biosphere Reserve UNESCO Heritage Center

Santuario de la Mariposa monarca