• HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
Wednesday, October 1, 2025
BIOENGINEER.ORG
No Result
View All Result
  • Login
  • HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
        • Lecturer
        • PhD Studentship
        • Postdoc
        • Research Assistant
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
  • HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
        • Lecturer
        • PhD Studentship
        • Postdoc
        • Research Assistant
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
No Result
View All Result
Bioengineer.org
No Result
View All Result
Home NEWS Science News Biology

Findings refute idea of monarchs’ migration mortality as major cause of population decline

Bioengineer by Bioengineer
August 17, 2020
in Biology
Reading Time: 3 mins read
0
IMAGE
Share on FacebookShare on TwitterShare on LinkedinShare on RedditShare on Telegram

IMAGE

Credit: University of Kansas Marketing Communications

LAWRENCE, KANSAS — In a new study, Monarch Watch Director Chip Taylor and colleagues have shown that speculation regarding the declining monarch population, despite having received much attention, is unsupported.

Published Aug. 7 in the journal Frontiers in Ecology and Evolution, the researchers show that the decline in the monarchs’ overwintering numbers is not due to an increase in the deaths of monarchs during the migration — the “migration mortality hypothesis.” The main determinant of yearly variation in overwintering population size, they found, is the size of the summer population.

Taylor, a University of Kansas professor emeritus of ecology & evolutionary biology, said the monarch butterfly populations have been declining for most of the last two decades. The numbers of monarchs measured at the monarch overwintering sites in Mexico in the winter of 2013-2014 were an all-time low.

The progressive decline in prior years, and these low numbers, led to the submission of a petition to the Department of the Interior to have the monarch declared a threatened species. These concerns also increased the search for an explanation for the decline.

The prevailing view was that the decline was due to habitat loss that followed increased use of glyphosate herbicide on corn and soybean fields in the Upper Midwest — the “milkweed limitation hypothesis.”

However, that view was challenged by a number of researchers who maintained that the decline was likely due to increasingly high levels of mortality during the butterflies’ migration. This became known as the migration mortality hypothesis.

Taylor said the migration mortality hypothesis, though unsupported by data, has received substantial coverage in Science and Scientific American.

“Monarch Watch has been collecting recovery data for tagged monarchs since 1992, and we knew that those advocating the migration mortality hypothesis were on the wrong track from the outset and told them so,” he said.

In this recently published study, Taylor and co-authors summarized the results of tagging almost 1.4 million monarchs that resulted in nearly 14,000 recoveries of tagged butterflies in Mexico.

“Showing the migration mortality hypothesis advocates their assumptions were wrong took awhile since that required a significant effort to vet our monarch tagging database for accuracy and to analyze the data,” Taylor said. “Dealing with 1.4 million records is no simple task.”

In contrast to the predictions of the migration mortality advocates, the tagging recoveries — a measure of migration success — did not decrease over time, the researchers found.

In addition, the number tagged each year was correlated with the size of the overwintering population in Mexico, consistent with the milkweed limitation hypothesis. The tagging also confirmed that the majority of monarchs reaching the overwintering sites originated from the Upper Midwest.

These findings support the conclusion reached by a team of experts that sustaining the monarch migration will require the restoration of over a billion milkweed stems in the Upper Midwest in the coming years.

###

The co-authors on the paper were John Pleasants of Iowa State University; Ralph Grundel and Samuel Pecoraro, both of the U.S. Geological Survey Great Lakes Science Center; and James Lovett and Ann Ryan of Monarch Watch and the Kansas Biological Survey.

Media Contact
Erinn Barcomb-Peterson
[email protected]

Original Source

http://news.ku.edu/2020/08/18/new-findings-debunk-idea-migration-mortality-major-reason-declining-population-monarch

Related Journal Article

http://dx.doi.org/10.3389/fevo.2020.00264

Tags: BiodiversityBiologyClimate ScienceEcology/EnvironmentEntomologyFertilizers/Pest ManagementGeographyPlant SciencesTemperature-Dependent Phenomena
Share13Tweet8Share2ShareShareShare2

Related Posts

blank

Mapping Resilient Dairy Cow Genes: A Cross-Breed Study

October 1, 2025
blank

Comparative Analysis of Catfish Species in Cage Culture

October 1, 2025

Decoding the Molecular Mechanisms Behind Long COVID Brain Fog

October 1, 2025

Genomic Insights into Schizopygopsis malacanthus Adaptation

October 1, 2025
Please login to join discussion

POPULAR NEWS

  • New Study Reveals the Science Behind Exercise and Weight Loss

    New Study Reveals the Science Behind Exercise and Weight Loss

    89 shares
    Share 36 Tweet 22
  • Physicists Develop Visible Time Crystal for the First Time

    74 shares
    Share 30 Tweet 19
  • How Donor Human Milk Storage Impacts Gut Health in Preemies

    62 shares
    Share 25 Tweet 16
  • Scientists Discover and Synthesize Active Compound in Magic Mushrooms Again

    57 shares
    Share 23 Tweet 14

About

We bring you the latest biotechnology news from best research centers and universities around the world. Check our website.

Follow us

Recent News

Laser Sintering 3D-Prints Silver Electronics in Space

Assessing Group Support for Parents of Autistic Teens

Can We Differentiate Distal Femur Variations from Lesions?

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 59 other subscribers
  • Contact Us

Bioengineer.org © Copyright 2023 All Rights Reserved.

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In
No Result
View All Result
  • Homepages
    • Home Page 1
    • Home Page 2
  • News
  • National
  • Business
  • Health
  • Lifestyle
  • Science

Bioengineer.org © Copyright 2023 All Rights Reserved.