Kip Hansen’s guest essay – June 8, 2022
Last March, I reported on these digital pages the miraculous and mysterious news that the annual census of the Western Monarchy in California revealed a get a raise in winter kings 100 times more Compared with the last year. The consensus of experts is that the Western exodus will manifest extinction.
But Nature doesn’t always listen to the experts and just do what it does.
“Butterflies hit a terrible record low last year [2020-2021], with fewer than 2,000 numbers across California. “…. “Last year, we were quite concerned that we were likely to face the reality that there would be no monarch butterflies in the western United States,” said Sarina Jepsen, director of the endangered species program at the U.S. Department of Health. Xerces Society” [ source ]
That quote by Sarina Jepsen is probably a misquote – no one thinks that King butterfly (Danaus plexippus) near extinction in the western United States. The fear is that the natural phenomenon known as the Western Monarchy Migration will be gone. “… In 1983, the IUCN took the unprecedented step of creating a new category in the Invertebrates Red List, to list monarch butterfly migration as a Threatened Phenomenon. This is because the number of Americans immigrating is plummeting.” [ source ]
This last March I report that due to the (probably) Covid pandemic, the usual annual census of the wintering monarchy in Mexico was not completed or was not reported. Now, finally, WWFcombine and cooperate with:
[These are, left to right, the Secretariat of Environment and Natural Resources (Mexico), the National Commission of Natural Protected Areas (Conanp), the Monarch Butterfly Biosphere Reserve, World Wildlife Federation, and the TELMEX Foundation.]
finally, released annual report as one four-page .pdf file.
Good news!
Executive Summary
In the second half of December 2021, 10 colonies of Monarch butterflies were registered on an area of 2,835 ha (ha) [about 7 acres] forest, this is an increase of 35% compared to the area registered in 2020 (2.10 ha). Six colonies covering 2,174 ha located inside the Monarch Butterfly Biosphere Reserve (MBBR) and four have an area of 0.661 ha located outside of MBBR, 5 of those colonies are located in Michoacan and 5 are in the State of Mexico.
The 35% increase is a far cry from the 100-fold increase seen in the exodus to California, but still good news. The exodus of Eastern monarchies still has a long way to go before returning to 1990s numbers.
The number this year is not as high estimate a site of the total “doubles” reported to me by Joel Moreno Rojas, moderator JM Butterfly B&B in Macheros, Mexico, adjacent to Cerro Pelón reserved. Cerro Pelon had the second largest colony this year, just exceeding Sierra Campanario.
Monarch experts disagree on what caused the near-fatal lows of 2013-2014 or the recent improvements. Most agree on the main culprit of population decline since the 1990s – changes in agricultural practices, including the use of Herbicide Roundup this has greatly reduced the prevalence of milkweed among field crops, such as corn, and has begun to be used to remove roadside weeds in addition to conventional lawn mowing. Aggregate effects on populations of milkweed, an essential food for monarch caterpillars, can be seen in monarch butterfly migration numbers. This is known as the “milk cotton restriction hypothesis.”
Chip Taylor, director of Monarch Watch, recently complete a study found that the number of kings that wintered in central Mexico was directly related to summer population size in the Midwestern United States.
Published August 7 in Frontiers in Ecosystems and Evolution, the researchers showed that the decline in wintering monarchs was not due to an increase in monarch moth deaths during migration – the “mortality hypothesis due to migrate”. They found the main determinant of the annual change in winter population size was summer population size.
The “migration mortality hypothesis” has been strongly promoted in Science and Scientific Americans. This hypothesis fits well with the Climate Change advocacy stories and is like this: “changes in climate are causing bad weather during a critical time of monarch butterfly migrations with hurricanes.” storms, droughts, high winds and higher temperatures”. However, Chip Taylor and his colleagues found:
“The migration mortality hypothesis that supports their assumptions is wrong because it requires a considerable amount of effort to examine their monarch tagging database,” said Taylor. I for accuracy and data analysis,” Taylor said. “Processing 1.4 million records is not a simple task.”
Contrary to the predictions of migration mortality advocates, the number of tagging recoveries – a measure of migration success – did not decrease over time, the researchers found.
“In addition, the number of tagged per year was correlated with the size of the wintering population in Mexico, consistent with the milkweed cap hypothesis. Tagging also confirms that the majority of kings arriving at wintering sites originated in the Upper Midwest. ” [ source ]
Monarch Watch’s research reinforces the need to restore milkweed to its original range and numbers. Restore the sua tree, restore the king species.
Monarchs have drawn themselves into a corner by requiring milkweed plants to spawn. This is a perfectly good idea as milkweed grows literally “everywhere”. It’s still popular but not nearly by the numbers seen in previous decades. In the Midwestern United States, milkweed will mature in large cornfields that never pass the seedling stage due to Round-up Ready farming. In my area, roads and highways, where milkweed thrives, are often cut down in late summer to coincide with the exact moment the caterpillars become super monarchs. migratory on milkweed.
All in all, this is encouraging scientific news, the monarchy of the West has risen in some mysterious way, the monarch of the East is recovering, and the need to grow more milkweed has been established through the through rigorous science and hard work.
Conclusion:
1) Migratory monarch butterfly populations are recovering – although the underlying reason for the strong recovery in the West is a mystery.
2) The actions needed to restore monarch butterfly migration to previously seen numbers are clear: a) encourage state and local agencies to stop mowing lawns along highways, especially with a particular focus on the Midwest, b) assist Mexico in combating illegal fishing in the monarch butterfly reserve areas of Mexico.
and
3) Can you help by planting beautiful native milkweed at your home or encourage your local park department to plant them in public gardens. Native Milkweed is available from many seed companies and commercial crops such as Spring Hill, Choose a seed, Gardens Alive or American grasslands. Search “net for”buy native succulent plants and seeds“.
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Author’s comment:
My wife manages a small public garden as a volunteer at our local public boat launch on the river. We encourage a few native succulents to grow as tall background flowers and have a few in our yard. They actually grow best in the “worst” places, which is why they are often found on highway banks and abandoned fields. She also grows a few vegetables among the flowers for visitors to enjoy – free cherry tomatoes to pick.
My fascination with Monarch Butterflies dates back to my youth in Los Angeles, California, where the Monarchs and Swallowtails can be found year round.
Monarch Watch good work – as proof that climate change is not the cause of the decline of kings – it also makes milk flakes available through Milkweed Market and through a program for Free milkweed for restoration projects program.
I generally disagree with international environmental organizations like WWF (which boasts that 82% of its donations go to environmental programs, which is “pretty good” – on the contrary, the organization charities my wife and I have worked for in the Dominican Republic give 100% of all donations to direct assistance programs, joint costs to be funded separately.) WWF in Mexico works well and is a key driver in the protection of the Monarch reserve in Central Mexico.
My other Monarchs essays are found here.
Thanks for reading.
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