Monarchs now ranked as ‘endangered’ in Canada
18 January 2024 | Author: Chip TaylorI started the year with a rant!
While traveling over the holidays, I received an email from Canadian Don Davis on 26 December informing me that “Monarch butterflies are now ranked under Canada’s Species at Risk Act as “Endangered”.” There was no indication of how this decision had been reached or who among the Canadian experts had been consulted. Such decisions have wide ranging effects, and since I’m rather protective about monarchs, and all for accountability, I penned the below on 1 January and hastily posted it to Dplex-L. The following is an improved version of that text. – Chip Taylor, Founding Director of Monarch Watch
These rulings are puzzling. They reveal that there is absolutely no understanding of the factors that determine the number of monarchs that appear in Canada each summer. It’s all about the timing and number of females reaching Canadian latitudes and longitudes from 12 May to 12 June. When monarchs arrive early in that time frame, and in good numbers, the populations are robust if summer conditions allow, and if late, the growth is limited, especially if summer conditions are limiting (low temperatures and/or precipitation). Before that, the number of first-generation monarchs moving north in May is largely determined by the numbers returning from Mexico and the conditions in March and April in Texas and Oklahoma that determined reproductive success by the returning monarchs. Given that reality, there is nothing that Canada can do to increase the timing and numbers of colonizing monarchs. The only thing that can be done is to maintain and restore monarch habitat and hope for favorable weather throughout the annual cycle.
Come to think of it, all of the above applies to the United States as well, doesn’t it? Except that the United States is less vulnerable to unfavorable low summer temperatures. If you go back through the earliest temperature records, which began in the United States in 1895, there were years such as 1915 when it was so cold from March through May that it was unlikely that there was much of a monarch population in either Canada or the United States (Figure 1). Going further into the climatic history suggests that monarch populations in both countries are more robust now than in many periods prior to the 1940s. The interval from 1976 to the present has been more favorable for population development than in earlier decades. Monarch numbers are largely temperature driven (the same for most invertebrates) with the maximum numbers at any time interval determined by the abundance, distribution and quality of the resources that favor reproductive success. Given these relationships, terrestrial invertebrates are more vulnerable to changes in the weather than vertebrates and therefore more difficult to sustain or restore. The Endangered Species Act has had some remarkable successes in the restoration of vertebrates, but given increasing temperatures and more variable precipitation throughout the continent, it seems less likely that endangered status will lead to effective restoration of terrestrial invertebrates such as monarchs and pollinators, and perhaps many temperature-sensitive aquatic invertebrates and fishes as well.
There are near-term and long-term realities when it comes to saving species of concern. In the near-term, to sustain what we can, we must engage in massive efforts to sustain and restore habitats and the resources these species require. At the same time, the long-term realities tell us that we must do all that we can to mitigate climate change.
The following is from a blog post last summer, Monarchs: Weather and population sizes in the past (monarchwatch.org/blog/2023/07/21/monarchs-weather-and-population-sizes-in-the-past).
Figure 1. Average March temperatures for Texas from 1895-2023.
There are three trends in these records: the high variation from year to year that ended in 1974, the damped variation from 1975 to perhaps 1994 and the progressive increase in temperatures from 1994 to the present. The average temperatures have increased 0.8F per decade since 1975 to 60.14 F vs the long-term (1900-2020) average of 56.3F. Note the five periods of 3-4 years in succession with extreme cold March temperatures. Such temperatures delay recolonization by monarchs returning from Mexico and recolonization of the summer breeding area north of 40N. These conditions would have led to smaller migrations and lower numbers overwintering in Mexico.
On another note. I keep seeing a dramatic shift in the temperature data that starts in the mid 1970s. I haven’t seen anyone comment on that in the climate discussions, but it is suggestive of something of a tipping point, especially for temperate invertebrates.
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You are an important part of our team as well. Your interest shows that you are aware of the need to sustain the monarch migration, and that means advocacy for all measures that can be taken to increase monarch numbers. Stated simply, we need to get plants in the ground – specifically milkweeds and nectar plants that support the breeding population and fall nectar plants that support the migration. The challenge is substantial and difficult to navigate. The climate is changing; we can see that in the data. March temperatures in Texas are becoming too warm, allowing monarchs to fly too far north too soon. In addition, high September temperatures are slowing the migrations, leading to fewer monarchs reaching the overwintering sites in Mexico. These sites also face threats due to droughts, beetle damage and illegal logging. While there is not much we can do to counter some threats, we can create Monarch Waystations, restore habitats, and inspire stewardship in the younger generations. These actions represent our mission at Monarch Watch, and we are grateful for your continued support.
Monarchs have a remarkable annual cycle – a breeding season in the U.S. and Canada and a non-breeding season as they overwinter for 5 months in Mexico. In effect, every year is the same, yet every year is different due to weather and other factors that influence reproductive success. We have a similar rhythm at Monarch Watch. Winter is spent catching up, writing, and planning for the next season, including our Spring Plant Fundraiser. Late spring and summer we work with nurseries to distribute milkweeds. Fall is all about tagging and public events and later seed collecting and processing followed by planning the number of milkweeds to be grown the next year.
So, while it might be said that each year is the same, they are all different – even more so this year. As you may remember, last year Founding Director Chip Taylor announced that he would be stepping away from the day-to-day operations of Monarch Watch to focus on writing and other projects. We are pleased to announce that the need for a new director has been met. Dr. Kristen Baum, known for her research on monarchs and pollinators, joined us at the end of October and we are still in the process of making the transition. Kristen’s first task as Director of Monarch Watch was to put together a five-year review of our activities. That took some time and a lot of digging into records and memories which enabled Kristen to get up to speed rapidly.
Monarch Waystations. We added more than 4,200 Monarch Waystations, bringing the total to over 46,000 registered sites. Our minimal target for next year is 50,000. Supporters can help by encouraging others to register and display our signs. If you see a sign in a prominent place, send us a photo – and a photo of your own Monarch Waystation as well! Share via 
Monarch Habitat. We worked with five nurseries to produce and distribute 156,000 regionally appropriate milkweed plugs in 2023. Free milkweeds were sent to 200 schools and non-profits and to those managing restoration projects in the Midwest, Texas, and California. Many were also distributed through our Milkweed Market. We could do much more if there was additional funding to support milkweed production and distribution.
Public Events. Thanks to everyone who joined us for our free public events in the spring and fall. These family events are both fun and informative. This year the tagging event at the Baker University Wetlands Discovery Center attracted over 400 people. It was a great day, and 577 monarchs were caught, tagged, and released. We hope you will join us when we hold these events next year – Spring Open House & Plant Fundraiser (May 11); Fall Open House (September 14); Fall Tagging Event (September 21).
After the findings were announced, Fred and Ken were widely lauded for the achievement; however, it is now clear that Catalina played a significant role in these discoveries. The “one last thing” in this case is the magnificent feature on monarchs in the January 2024 issue of National Geographic. The article is something of a commemoration of the events in early 1975. The photography by Jaime Rojo is extraordinary and the text by Michelle Nijhuis provides a glimpse of the diverse ways many scientists, conservationists and thousands of individuals are engaged with monarchs. It’s a far cry from the singular efforts by Fred and Norah Urquhart to answer a question that had lingered since the days of C. V. Riley and others in the 1860s. The question for more than 100 years was where and how monarchs spend the winter. Now, a mere fifty years later, the question has become How can we sustain the monarch migration?
In 1992, I started a small monarch tagging project with the help of Brad Williamson, a local high school science teacher. That project attracted the attention of the public and led to the creation of Monarch Watch. Although we characterized Monarch Watch as focused on education, conservation, and research, in the early years, most of our efforts involved educational outreach and research. My thought at the time was that conservation would take care of itself. I was wrong. That became apparent when I received an email from a farmer in Nebraska in 2004 who informed me that the new genetically modified crop lines he had adopted were leading to the loss of milkweeds in his corn and soybean fields and that in turn was reducing the number of monarchs on his farm. Alarmed at this news, I knew we had to shift our emphasis to conservation. Although struggling financially at the time, we decided to start the Monarch Waystation program in 2005. The program has grown, and we now have over 46 thousand registered sites. Once we became more financially secure, we began to work with nurseries to produce milkweeds that could be used in these Monarch Waystations and for restoration. 
Although educational outreach and research continue, our main focus has become monarch and pollinator conservation. Over the years, we have facilitated the growth and distribution of over 1 million milkweed plugs. We were the first organization to step into this role and are proud of these efforts.
