Tag Archives: Monarch Watch

HELLO MONARCH ACTU 676! – WHAT TO DO IF YOU FIND A TAGGED MONARCH

Good morning Butterfly Friends!

I hope you were able to get out and enjoy the glorious weather this past weekend! We dropped off our daughter Liv at Logan on Saturday. It was a dream having her home during this broken leg period and I am so grateful for her kind and loving care. We’ll all miss her terribly but her work and beautiful California call and we understand.

I graduated from the giant boot to the mini boot several weeks ago and am now doing well hopping around with only one crutch, which means, joyfully so, I can carry my cameras with my free arm! While out in marshes over the weekend I photographed a living tagged butterfly. I don’t usually see living tagged butterflies, only dead ones. Unfortunately, in the past, I have been in a field after a bunch of children ran unsupervised in catching and tagging butterflies, without proper training. Many were killed and/or mangled. Fortunately, male Monarch ACTU 676 appeared just fine and was flying well.

Only a small fraction of the butterflies tagged are actually recovered at their wintering grounds in the volcanic mountains of Mexico. Some are spotted near to where they were tagged, some along the migratory route, and the ones recovered and recorded in Mexico provide a meaningful connection between the tagger and the recoverer.

If you find a tagged Monarch, alive or dead, please go to the official online tagging form provided by Monarch Watch. You can find the 2020 -2021 form here and it looks like this screenshot –

As you can see, it’s a basic form and there is a link provided to add a photo. By submitting your sighting, you as a citizen scientist are participating in a long term study, first developed by Monarch Watch in 1992.

Please join us Thursday, September 23rd at 7pm for the world Live Premiere of Beauty on the Wing at the Shalin Liu, presented by the Boston Film Festival and Rockport Music. For more information, please go here.

Happy Butterfly Days,

xxKim

NEW STUDY BY MONARCH WATCH CHIP TAYLOR REFUTES “MIGRATION MORTALITY” AS THE MAJOR REASON FOR THE DECLINE OF THE MONARCHS

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Female Monarch depositing egg on Common Milkweed (Asclepias syriaca)

Evaluating the Migration Mortality Hypothesis Using Monarch Tagging Data

Frontiers in Ecology and Evolution

August 7, 2020

Authors:

Orley Talor, Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, United States

John M. Pleastant, Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA, United States

Ralph Grundel, U.S. Geological Survey, Great Lakes Science Center, Chesterton, IN, United States

Samulel D. Pecoraro, U.S. Geological Survey, Great Lakes Science Center, Chesterton, IN, United States

James P. Lovett, Monarch Watch, Kansas Biological Survey, University of Kansas, Lawrence, KS, United States

Ann Ryan, Monarch Watch, Kansas Biological Survey, University of Kansas, Lawrence, KS, United States

The decline in the eastern North American population of the monarch butterfly population since the late 1990s has been attributed to the loss of milkweed during the summer breeding season and the consequent reduction in the size of the summer population that migrates to central Mexico to overwinter (milkweed limitation hypothesis). However, in some studies the size of the summer population was not found to decline and was not correlated with the size of the overwintering population. The authors of these studies concluded that milkweed limitation could not explain the overwintering population decline. They hypothesized that increased mortality during fall migration was responsible (migration mortality hypothesis). We used data from the long-term monarch tagging program, managed by Monarch Watch, to examine three predictions of the migration mortality hypothesis: (1) that the summer population size is not correlated with the overwintering population size, (2) that migration success is the main determinant of overwintering population size, and (3) that migration success has declined over the last two decades. As an index of the summer population size, we used the number of wild-caught migrating individuals tagged in the U.S. Midwest from 1998 to 2015. As an index of migration success we used the recovery rate of Midwest tagged individuals in Mexico. With regard to the three predictions: (1) the number of tagged individuals in the Midwest, explained 74% of the variation in the size of the overwintering population. Other measures of summer population size were also correlated with overwintering population size. Thus, there is no disconnection between late summer and winter population sizes. (2) Migration success was not significantly correlated with overwintering population size, and (3) migration success did not decrease during this period. Migration success was correlated with the level of greenness of the area in the southern U.S. used for nectar by migrating butterflies. Thus, the main determinant of yearly variation in overwintering population size is summer population size with migration success being a minor determinant. Consequently, increasing milkweed habitat, which has the potential of increasing the summer monarch population, is the conservation measure that will have the greatest impact.

Introduction

Since the late 1990s, the monarch butterfly, Danaus plexippus, population has declined significantly based on measurements made at the Mexican overwintering grounds (Brower et al., 2011; Semmens et al., 2016). Identifying the cause or causes of the decline is important in order to focus conservation measures appropriately. Two explanations for the decline in the size of the overwintering population dominate the literature. The first, known as the “milkweed limitation” hypothesis, posits that the decline in the number of milkweed host plants in the major summer breeding area in the Upper Midwest of the U.S. (Figure 1) has led to a reduction in the size of the migratory population (Pleasants et al., 2017). The second, known as the “migration mortality” hypothesis, posits that the resources and conditions during the fall migration have declined resulting in an increase in mortality during the migration and a decline in the overwintering population (Agrawal and Inamine, 2018).

Figure 1. All wild-caught butterflies tagged from north of 40° latitude and east of 100° longitude were included in the study. This area includes the region we are calling the Midwest, encompassing the area from 40 to 50° latitude and 80 to 100° longitude (outlined in red) and the region we are calling the Northeast, encompassing the area from 40 to 50° latitude and 65 to 80° longitude (outlined in blue). What we are calling the Total Area is the Midwest and Northeast combined. The NDVI values (Saunders et al., 2019) come from the region that encompasses the area from 30 to 40° latitude and 90 to 105° longitude (outlined in green). The dark blue square indicates the location of the overwintering colonies. Butterflies were tagged in other sectors besides the Midwest and Northeast but those data are not included in this study.

The milkweed limitation hypothesis is supported by data showing that in the early 2000s the majority of monarch production came from common milkweed, Asclepias syriaca, in corn and soybean fields in the Midwest (Oberhauser et al., 2001) and that the abundance of those milkweeds declined precipitously due to glyphosate herbicide use in those fields (Pleasants and Oberhauser, 2013; Flockhart et al., 2015; Pleasants et al., 2017; Thogmartin et al., 2017a; Saunders et al., 2018). The loss of the milkweeds from corn and soybean fields began in the late 1990s with the adoption of glyphosate-tolerant crops. Milkweeds had been nearly eliminated from these fields by 2006 (Pleasants, 2017). During this period, an estimated 71% of the monarch production potential of milkweeds on the Midwest landscape was eliminated, amounting to 25 million hectares of agricultural habitat that no longer had milkweeds (Pleasants, 2017). The subsequent decrease in the availability of milkweed is thought to have limited the size of the summer breeding population. Support for this hypothesis comes from the pattern of decline in milkweed availability that parallels the decline in the size of the overwintering population (Pleasants et al., 2017). Further support comes from the strong correlation between yearly late summer Midwest monarch egg production and yearly overwintering population size (Pleasants and Oberhauser, 2013; Pleasants et al., 2017).

EASTERN MONARCH BUTTERFLY POPULATION PLUMMETS BY MORE THAN HALF

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How disappointing to see the Monarch numbers plunge to less than half of last year’s population. Scientist Chip Taylor from Monarch Watch predicted lower numbers, but not to this degree. It’s hard to believe, especially after witnessing the tremendous numbers at Cerro Pelon in 2019, along with the beautiful migration through Cape Ann last summer.

Plant a variety of milkweeds and wildflowers to help the Monarchs on their northward and southward migrations

The chief reasons for this year’s loss of Monarchs are decreasing amounts of wildflowers on their migratory route south, bad weather during the 2019 migration, and the continued spraying of deadly chemical herbicides and pesticides on genetically modified food crops.

As we are all aware, Monarch caterpillars only eat members of the milkweed (Asclepias) family, but the plant has been devastated by increased herbicide spraying in conjunction with corn and soybean crops that have been genetically engineered to tolerate direct spraying with herbicides. In addition to glyphosate (Monsanto’s Roundup, which is now owned by Bayer), Monarchs are threatened by other herbicides such as Dicamba and by neonicotinoid insecticides that are deadly poisonous to young caterpillars and decrease the health of adult butterflies.

In 2014, conservationists led by the Center for Biological Diversity and the Center for Food Safety petitioned the U.S. Fish and Wildlife Service to protect the butterfly under the Endangered Species Act.

The decision on Endangered Species Act protection will be issued in December of this year under a settlement with the conservation groups. The low count of 2019-2020 reinforces the need to protect what we already know to be an endangered species.

HIGHER NUMBERS GIVE HOPE FOR MONARCHS

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By Kim Smith

January 31, 2019

The World Wildlife Fund Mexico and Monarch Butterfly Biosphere Reserve (MBBR) announced on January 30th that this year the Monarch Butterfly population has increased significantly.

Each year the orange and black winged beauties return to the oyamel fir and pine tree forests, which are located in the heart of Mexico’s trans volcanic mountain belt. In December and January, Lepidoptera population specialists and citizen scientists measure the area the Monarch colonies cover at their over wintering sites. This year (2018-2019) the butterflies are blanketing 6.05 hectares (approximately 15 acres), up from an all-time low of only 0.67 hectares (1.65 acres) during the winter of 2013-2014.

Not since 2006-2007 has this great an area been covered by the butterflies, although the numbers are still quite low when compared to the numbers recorded in the late 1970s when the butterfly’s winter roosts were first discovered by Dr. Fred Urquhart.

I have been following the butterfly counts around the US as they were reported. The Monarch population has been decimated in California. This year only about 30,000 butterflies were counted, down from several million just two decades ago. There is the very real possibility that the Monarch butterfly will become extirpated (extinct from an area) on the West coast. The winter count is down drastically in Florida as well.

It was clear though that east of the Rockies–the Midwest and Northeast regions of the US, as well as southern provinces of Canada–there were many more Monarchs in gardens and on the wing than in recent previous summers.

Leading Monarch scientists are reluctant to become excited about the increase, and justifiably so. Last spring the weather was slightly cooler in Texas, which allowed more Monarch eggs to hatch, which in turn allowed more caterpillars to mature. A greater number of butterflies emerged and set the stage for a strong breeding season throughout the summer. That scenario, along with the overall good weather during the summer of 2018, also helped create ideal conditions. It was a true “goldilocks” summer, not too hot, not too cold, but just right.

In autumn of 2018, the Monarchs arrived to Mexico about a week later than usual, but once they began to arrive, a kaleidoscope of butterflies poured into their winter roosting grounds.

The 2018-2019 Eastern population count is a reprieve from the past ten years of heartbreaking news, but one good year does not change what the butterflies need most, which is protection for the Monarchs under the Endangered Species Act.

Monarch and Mexican Sunflower (Tithonia)

There is disagreement among scientists whether planting milkweed has any bearing on the health of the Monarch butterfly population. Does creating corridors of Monarch habitat help mitigate the death and destruction caused by climate change, modern agricultural practices, the devastating use of pesticides and herbicides, and the planting of GMO crops (corn, sorghum, and soybeans, for example) that were engineered to withstand the deadly poisons, but which wildflowers and caterpillars cannot?

Monarch Butterflies and New England Aster, Gloucester, 2018

The answer to that question is a resounding yes! Monarchs are a bellwether species. The love for this one butterfly has helped shape a consciousness towards all species at risk. An uncomplicated stand of milkweed and asters can make every public walkway, park, community center, church, school, and backyard a haven for Monarchs and together we can bring about a conservation victory for the pollinators.

Xerces Society letter to President Obama

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April 14, 2014

President Barack Obama The Honorable Tom Vilsack, Secretary of Agriculture The Honorable Sally Jewell, Secretary of the Interior

Dear Mr. President, Mr. Secretary of Agriculture, and Madam Secretary of the Interior,

In light of the severe decline of both the eastern and western monarch butterfly populations that has occurred since the late‐1990s, we are writing to ask you to establish a multi‐agency monarch butterfly recovery initiative to restore the habitats that support the extraordinary migrations of this iconic species. We encourage you to direct the Natural Resources Conservation Service (NRCS), Farm Service Agency (FSA), and Forest Service (USFS) of the U.S. Department of Agriculture and the Fish and Wildlife Service (USFWS) and Bureau of Land Management (BLM) of the U.S. Department of the Interior to develop a cooperative, landscape‐ level initiative with the many stakeholders willing to help foster significant monarch recovery.

These migrations can be saved for future generations by restoring to the landscape milkweeds, the host plants for monarch caterpillars, and nectar plants that sustain the adult butterflies. These habitats would support pollinators and a large number of other species as well. The federal agencies that incentivize conservation of wildlife habitat on private lands and that directly manage wildlife habitat on public lands can play key roles in this effort by targeting funding and technical support for such an initiative.

As you know, the eastern monarch population has been declining for more than a decade, and this year scientists observed the lowest numbers ever documented, representing a 90% drop from population numbers recorded in the mid‐1990s. Since then, there has been a significant loss of milkweeds in agricultural areas of the Midwest, which is directly correlated with the declining monarch population. Monarch habitat has also declined sharply in the West.

Paul Mirocha Illustration for Monarch Watch

A landscape‐level monarch butterfly recovery initiative led by the NRCS and FSA on private lands would incentivize the planting of native milkweeds and butterfly nectar sources in places that are protected from pesticide and herbicide use.

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