It’s a lonely fall for those of us who love being observers of the annual migration of monarch butterflies (Danaus plexippus) back to Mexico, a 3,000-mile journey that is breathtaking for its scope and its beauty. If we could connect all the dots of all the trajectories and innumerable stops for nectar to fuel the journey, we would see a pattern, a living tapestry, so instructive of the importance of thinking ecologically.
I have recently been migrating myself, from Ithaca, New York to Harrisville, New Hampshire, back to Ithaca, and now south to western Virginia. Having heard that a 90% decline in migratory numbers was predicted for this fall, I have been looking for monarchs in old and new haunts. In Harrisville, I saw one monarch, in Ithaca three, and one in Vinegar Hollow. In past years, significant numbers have accompanied me on my daily dog-walking rambles. Being with them, admiring their determined, zig-zaggy flitting, from blossom to blossom, I have felt part of the hero’s journey, the voyage home, a mythology rooted in biology.
The media have documented the decline in monarch numbers more authoritatively. The figure given since January 2014 is a 90% decline. For graphs, see the website of the Xerces Society for Invertebrate Conservation and an article in the Washington Post by Brad Plummer. Plummer reports a conversation with Lincoln Brower of Sweet Briar College, one of the world’s foremost monarch experts, who outlines three causes for the decline: deforestation in Mexico, severe weather issues (e.g., the 2013 drought in Texas), and herbicide-based agriculture. I remember a lecture given by Brower at Cornell a few years ago, in which he noted that efforts to create a monarch reserve in Mexico had in fact led to more poaching by illegal loggers than before its creation. All monarchs have to fly through Texas, so not much can be done to prevent a decline due to drought. It is important to know, however, that monarchs flying south need to feed heavily on nectar, some of which they store for use during the winter “hibernation.” You might say that blossoms are their gas stations. The issue of herbicide-ready agriculture is big and contentious.
Citing the figure of a 97% decline, Richard Coniff in a post on his “Strange Behaviors” blog is pointed in stating that it’s now a question of Monsanto vs. the Monarchs. Since Monsanto developed Round-up ready soybean and corn seed in the 1990s, the widespread of this seed, which enables large-scale herbicide spraying, in the Midwest has wrecked havoc with the life-supporting patchwork of milkweed species hanging out here and there in fields and along roadsides. It takes four generations of monarchs to hatch and breed and feed on milkweed foliage, on their way across the United States to Canada. Milkweed species are said to show a 67% decline in numbers.
Coniff notes that farmers are not the problem and believes that Monsanto has the money to establish milkweed-friendly zones around agricultural fields. Apparently Monsanto is presently studying whether the fear of monarch extinction is legitimate, and whether it wishes to be part of conservation efforts.
We can all plant milkweeds. There are 110-120 species, of which 32 are particularly helpful for monarchs. Coniff offers a link to supplier of milkweed seeds and plants. Milkweeds in themselves are a wonderful group of plants with a unique floral structure (see this additional Xerces posting) (and this one showing the common milkweed [Asclepias syriaca]), complete with horns, hoods, and corpuscula. Many of us in the northeast know the common milkweed, its fleshy, drooping, dusty-rose flowers, hypnotically scented, but there are many other milkweed species
with the same fascinating flowers perfected in different sizes and shapes (scroll down to the bottom of this link).
MonarchWatch.org, led by Chip Taylor, is an excellent organization/website offering information on the biology of monarchs and milkweeds and on conservation efforts. Many people are now hosting monarch “waystations” under the guidance of MonarchWatch.
Monarchs have been called “iconic” and their flight “epic,” and rightfully so. Every school child in North America has known their story. Many have watched, as I have, the chrysalis become butterfly in just seconds, miraculously, as the molecules reorganize themselves from immobile jewel case into polka-dotted flight machine. And there is more to learn. Just last week, National Geographic posted an article on new discoveries about the genetics behind the white monarch and the efficiency of flight muscles in the migratory monarch. They continue to inspire our creativity, as in this book shown below about a biologist coming home to Lake Erie to study monarch migration, or this new Harrisville Watershed yarn called “Monarch” (click on it, sitting to the left of “Barn Red,” for a close-up).
There are many good people working to ensure a future for monarchs, so that they do not become part of a mythic past. And there are many good weeds and wildflowers ready to be part of the ongoing story.
P. S. For an article on the migration of Fall 2014, see this article titled “For the Monarch Butterfly, a Long Road Back” by Liza Gross.