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New Monarch Butterfly Studies May Provide Reasons for Optimism

Eight new articles on monarch butterflies were published today in the Annals of the Entomological Society of America.

“This group of papers is intended to give us the latest and best data available on the status of monarch populations and perhaps point the way to our best efforts to protect them,” said Lawrence E. Hurd, editor-in-chief of the journal.

Unlike many past studies that relied on monarch populations in Mexico, where they overwinter, the authors of these studies observed monarch populations in Canada, Michigan, Pennsylvania, and other U.S. states. Results vary, but some studies found no significant declines of monarch populations in their summer breeding areas.

“I think we’ve really been focused too much on Mexico,” University of Georgia ecologist Andy Davis, a co-author of one of the papers, told the Washington Post. “If you were charged with figuring out how many people are participating in the Boston Marathon each year, you wouldn’t count the number of people who cross the finish line. But for many years we’ve been counting the finishing monarchs in Mexico. We’ve been doing it backwards.”

The titles and authors of the articles are:

– “Long-Term Trends in Eastern North American Monarch Butterflies: A Collection of Studies Focusing on Spring, Summer, and Fall Dynamics” by Andrew K. Davis

– “Investigating Long-Term Changes in the Spring Migration of Monarch Butterflies (Lepidoptera: Nymphalidae) Using 18 Years of Data from Journey North, a Citizen Science Program” by Elizabeth Howard and Andrew K. Davis

– “Habitat Productivity and Temporal Patterns of Monarch Butterfly Egg Densities in the Eastern United States” by Carl Stenoien, Kelly R. Nail, and Karen S. Oberhauser

– “Immature Monarch Survival: Effects of Site Characteristics, Density, and Time” by Kelly R. Nail, Carl Stenoien, and Karen S. Oberhauser

– “The Disconnect Between Summer and Winter Monarch Trends for the Eastern Migratory Population: Possible Links to Differing Drivers” by Leslie Ries, Douglas J. Taron, and Eduardo Rendon-Salinas

– “Population Trends of Monarchs at a Northern Monitoring Site: Analyses of 19 Years of Fall Migration Counts at Peninsula Point, MI” by Gina Bdgett and Andrew K. Davis

– “Long-term Trends in the Number of Monarch Butterflies (Lepidoptera: Nymphalidae) Counted on Fall Migration at Long Point, Ontario, Canada (1995-2014)” by T.L. Crewe and J.D. McCracken

– “Trends Observed in Fall Migrant Monarch Butterflies (Lepidoptera: Nymphalidae) East of the Appalachian Mountains at an Inland Stopover in Southern Pennsylvania over an Eighteen Year Period” by Gayle Steffy

Click here for the articles.


  1. Better reasons for optimism: There are literally hundreds of thousands of miles worth of rural gravel farm road ditches in the upper Midwest and 70% of them still have syriaca milkweed and monarch butterflies. Some examples: Those billion+ syriaca milkweeds support a population of tens of millions of monarch butterflies that breed next to the GMO crops.
    The butterflies are still so abundant that some GMO crop farmers themselves have been posting photos of hundreds of monarchs gathered in the shelter belt trees that bordering their crops and farm buildings like the South Dakota farmer did Sept. 2014:

  2. Paul you have no clue, the amount of “ditch habitat” compared to historic habitat is like comparing a pond to an ocean – there is no comparison. If GMO farmers are taking photos with Monarchs in trees next to their fields, then we know something is wrong as Monarchs would normally be in the fields, not roosting in trees during peak breeding season. GMO crops are one of the main reason for the decline in Monarchs, I have seen your disinformation posts on about a dozen sites that talk about monarchs, are you employed by Monsanto?

    Here is a fact, Monarchs have declined from nearly a billion 20 years ago to 33 million today.

    Stop your propaganda Paul.

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