The story begins in Chapter One Baby Monarchs and Barfing Blue Jays with the life cycle of the monarch butterfly, starting with the tiny caterpillar which hatches out of a very small egg on the underside of a milkweed plant. The complex relationship between the monarch caterpillar which requires the milkweed plant to survive and the milkweed plant which needs to protect its leaves is described. Key to this relationship are the many survival strategies the monarch caterpillar has developed. These include how to circumvent the tiny spiky hairs on the milkweed leaf and the toxic white oozing liquid of the plant which also acts as a glue. There are several types of milkweed plants and the monarch caterpillars have developed strategies to survive on each.
Each stage of the monarch caterpillar's life from its five molts to the preparations it makes to pupate, where it forms a chrysalis and undergoes metamorphosis to a butterfly are described with many interesting details.
The research of Dr. Fred Urquhart and his wife Norah are the focus of Chapter Two. Where Do They Go? Urquhart's interest in monarchs began as a boy and carried on through the rest of his life. Dr. Fred Urquhart had plenty of questions about monarch butterflies: Where do monarchs go for the winter? Do they have somewhere safe and warm to rest or do they die off? One article Fred read suggested that monarchs overwinter in Canada and the Northern United States. But he could find no evidence of this. Dr. C.B. Williams, a scientist in England, suggested "...that monarchs fly down to the Gulf Coast in Florida to overwinter and return in the spring." In 1935, Dr. Urquhart began to investigate this theory by tagging monarch butterflies.
Eventually the Urquharts were able to develop a successful way to tag monarchs and enlist the help of volunteers across North America. They formed the Insect Migration Association and created an annual newsletter. The tagging program showed that the monarchs' flight paths began in northeast Canada and ended along the US Gulf Coast and in Texas.
In Chapter Three More To The Story, the hard work and determination of Kenneth Brugger and a Mexican woman, Catalina Trail would provide the answer as to where the monarchs overwinter. Their work to determine the overwintering location was crucial to Fred and Norah's research. The Urquharts did not know where the monarchs travelled after they left Texas and the Gulf area. Trail and Brugger would discover two overwintering sites: Cerro Pelon and Sierra Chincua.
What followed was controversy and rivalry after Fred Urquhart published a fourteen-page article in the August 1976 issue of National Geographic magazine. The article paid only a passing mention of the work of Brugger and Trail and failed to honor the promise to keep the overwintering sites completely secret. The reality was that the Urquharts didn't "discover" the overwintering sites as it's likely the Indigenous and local people of Cerro Pelon already knew of them. After all, they cared for the forests and lived on the land.
Urquhart's article did create intense public interest from both scientists and citizens. One person deeply interested was Dr. Lincoln Brower. In Chapter Four Squabbling Scientists, the relationship between Brower and the Urquharts is explored. What started on friendly terms quickly became a bitter rivalry as the Urquharts refused to share the location of the overwintering sites. Brower had developed a unique method of fingerprinting monarch butterflies using the cardenolide they ingested from the milkweed plants. Milkweed contains a poison in its roots, leaves, milk, seeds and nectar called cardenolides. This fingerprint allowed scientists to determine where the monarchs had originated based on the type of milkweed they had ingested.
Even after the publication of the National Geographic article, the Urquharts would not reveal the location, so Brower took matters into his own hands. He used clues from the article to help: "The overwintering colony...was located on the slope of a volcanic mountain situated in the northern part of the State of Michoacan, Mexico, at a height of slightly over 3000 m." With the help of a fellow scientist, Dr. William Culvert, and topographic maps, Brower located the Sierra Chincua site. Incredibly, Brower and Culvert encountered the Urquharts at the site and an unfortunate accident that resulted in the deaths of millions of monarchs did not improve the situation. Perhaps one of Brower's most significant contributions to monarch butterfly science was the system of cardenolide "fingerprinting" he developed, which allowing researchers to determine a monarch butterfly's location of origin.
Dr. Brower and his team's research is explored in detail in Chapter Five Secrets of the Forest. Brower's research considerably expanded our knowledge "...about monarch butterflies, their predators, and the special climate of the Mexican overwintering sites." They demonstrated that importance of the oyamel forests in the Trans-Mexican Volcanic Belt to monarch butterfly survival. His research uncovered how the monarch migration northward to Canada works. They revealed that ",,,successive generations of monarchs lay eggs farther and farther north until they reach southern Canada."
Chapter Six Tracking Migration, explores scientists efforts to better understand monarch migration focusing on the pace of migration and the factors that might be affecting migration. This chapter also explores research into two models, the milkweed limitation hypothesis and the migration mortality hypothesis as reasons for the decline in monarch population.
As research into monarchs expanded, scientists realized they needed to be studying more than just monarch migration, In Chapter Seven, Tracking More Than Migration, the work of several scientists including Dr. Kelsey Fisher and Dr. Karen Oberhauser is featured. Oberhauser initiated studies on monarch egg counts while Fisher, who studied movement ecology, wanted to understand how monarchs find milkweed plants, how they locate the Mexican overwintering sites for the first time and how monarchs know it's spring and time to head north again.
Chapter Eight, Monarch "Smarts" explores in greater detail the science behind monarch migration. Scientists wanted to discover how an insect with a such a tiny brain knows to fly three thousand miles south to an area approximately seventy-three miles wide. In order to understand this, researchers needed to understand monarch biology: researchers studied how their antennae functioned, the chemoreceptors and mechanoreceptors that monarchs relied on, how their eyes work and much more.
Chapter Nine Monarchs Around The World, asks the question "Where did monarch butterflies come from?" To answer this question, the fossil record is considered and genomics, the study of genes has been used to try to answer this question. This chapter also explores where other populations of monarchs are found in the world.
The significant decline of the western monarch population which is located west of the Rocky Mountains is explored in Chapter Ten Monarch Emergencies. This population spends spring and summer in Nevada, Idaho and Oregon and overwinters along the coast of California. The chapter also considers the decline in the eastern monarch migration.
In Chapter Eleven Living Near The Monarchy, the efforts to protect the habitat of overwintering monarchs is discussed. The work of Dr. Columba Gonzalez-Duarte has focused on evaluating the Monarch Biosphere conservation model and found it wanting. This model has led to the unintended loss of the traditional way of life for local Mexicans living on the lands and have also led to the proliferation of organized crime. This chapter outlines the many problems of the model both for the butterfly and forest conservation and for the people living in the ecosystem. Instead, Gonzalez-Duarte proposes focusing on the entire habitat instead of just one species might be more successful to saving both monarchs and Indigenous culture and way of life.
Discussion
The Monarch Effect offers readers a deep dive into the world of the monarch butterfly and the research being done to understand this remarkable and beautiful insect.
Dana Church provides her readers with fascinating information on almost every aspect of the monarch butterfly. The Monarch Effect opens with a detailed introduction of the life cycle of the butterfly that includes many interesting facts readers will likely not know. For example, many readers will know that the milkweed plant contains a poison, called cardenolide which is found in every part of the plant. But did you know it is also toxic to monarch larvae? Church writes, "Less than half of all monarch caterpillars survive the milkweed's latex...If the amount of latex a caterpillar ends up accidentally eating doesn't kill the, they can recover in five to ten minutes. Otherwise, they end up in a nonresponsive, coma-like state and die." The author describes the various survival strategies monarch caterpillars employ to survive on different species of milkweed and then goes on to describe the rest of the life cycle.
From this point on, the focus of The Monarch Effect is to present the incredible amount of research that has been done in the last eighty years on monarchs beginning with the initial monarch research in the early 20th century by Canadians, Fred and Nora Urquhart into where exactly monarchs overwintered. Like many other scientific endeavours, such research was not without controversy and to that end Church presents a balanced account of the rivalry between the Urquharts and Dr. Lincoln Brower, an American researcher who contributed significantly to our understanding of monarch butterflies. She also highlights the bias of this early research in believing it "discovered" the monarchs overwintering sites, which were already known to the Indigenous peoples of Mexico.
Throughout the book, Church highlights the many questions that arose as scientists learned more about monarchs. "...How do monarchs know when to start migrating? As they migrate, do they fly at a steady speed along the entire journey, or do they speed up or slow down at certain points?" How does weather impact monarch migration? Does the angle of the sun affect the migration? Other researchers wanted to know which US states monarchs arrived at first in the spring. When does the spring migration begin? Why does the timing and duration vary each spring? When the monarchs arrive in Mexico how do they choose where to roost? Do the same butterflies always roost together? How do monarchs locate milkweed plants? How do they decide on which plant to lay their eggs? As Church demonstrates, each piece of information led to more and more questions and required researchers to devise unique ways to find the answers.
Several chapters are devoted to answering questions about the decline of monarchs and how we can best help the species recover. As with many environmental issues, the problems are complex and multi-faceted. Scientists are now advocating for a combined approach that utilizes both Indigenous and Western traditional science knowledge. It is an approach that considers not just monarchs, but the entire ecosystem and habitat, one that better integrates humans with the natural world they are a part of. This will require removing bias and require international cooperation to succeed.
The Monarch Effect is engaging and informative, written in an easy style, with understandable explanations about the complex problems facing monarch butterflies and the communities they are a part of. The eastern monarch spans three countries, vastly different ecosystems, and different cultures. The author encourages her readers to become involved in the monarch butterfly recovery efforts by sending monarch sightings to Journey North, helping with tagging monarchs at monarchwatch.org and even counting monarch eggs and larvae through Monarch Joint Venture. The book offers websites that citizen scientists can access to become a part of this important work.
The Monarch Effect is perfect for the budding entomologist and those interested in the natural world. Church includes a detailed Glossary and an extensive References list at the back to help with further research and reading.
Book Details:
The Monarch Effect: Surviving Poison, Predators, and People by Dana L. Church
New York: Focus Scholastics 2024
309 pp.
The Monarch Effect: Surviving Poison, Predators, and People by Dana L. Church
New York: Focus Scholastics 2024
309 pp.
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