About Monarch Butterflies
This is about the time the monarch butterflies remaining in Southcentral Washington State – largely down around the Tri-Cities – start south to California. While many of the monarchs across the central and eastern parts of the U.S. (and Canada) are beginning to return from serious trouble over the past couple decades, our western monarchs continue their precipitous drop in numbers.
What got me thinking about monarchs was a weekend travel radio show. One of the guests arranges and books winter tours to Mexico, where guests may see as many as a million monarch butterflies in the (I gathered) Michoacan Highlands. While the promoter told great stories about the monarchs and their amazing migrations, breeding and life cycles, the stories contained several glaring errors.
As Chief Butterfly Information Officer for the Reecer Creek Rod, Gun, Working Dog & Outdoor Think Tank Benevolent Association, I suggest we briefly review what we know about this most royal of butterflies. Monarch’s scientific name is Danaus plexippus (named after Danaus, a mythical king of Egypt and son of Zeus).
The monarch is a new-world butterfly, found from Hudson Bay to Patagonia (and now reported in Europe, Australia and New Zealand). AKA the milkweed butterfly, this one is spectacular. Its orange-brown or reddish upper wings have veins outlined in black and surrounded by broad black borders with two rows of white spots. Its wings may spread four inches. It is not unusual to see magazine or television images of monarchs so thoroughly covering roosting trees during migration that the trees seem to be in full fall color.
It is mind-boggling to imagine such fragile, delicate creatures flying as many as 2500 miles each year; from winter in southern California and central Mexico to summers in the U.S. and southern Canada (following several flowers and milkweed) and then south again. The migration itself seems highly dependent on surface features, with only rare long flights over water. The monarchs appear to learn over time (some observations indicate that north-south trending highways or railroad tracks have been incorporated into migration routes). Here is the most fascinating aspect of their story: while the butterflies have made this annual migration for untold time, they habitually return to the same trees, no single butterfly makes more than two-thirds or three-quarters of the trip.
So, do the young just follow, or communicate somehow with the older, slightly more experienced, adults? Or is there some ancient genetic coding at work? Let’s just say that more is learned each year.
The butterflies generally breed in wintering grounds in Mexico and Southern California, with fertile eggs carried north to just the right milkweed patch. Some breeding (as many as a couple different cycles) also takes place in summer habitat. Once the eggs have been laid, the cycle of ovum (egg), larva (caterpillar), pupa (chrysalis) and imago (adult) will begin anew. The eggs must hatch in time for the adults to get south before cold weather, but there is more to the story. With increased interest and observation we now know that the butterfly doesn’t only go through its four life cycles annually, it often also goes through four generations in a year. Check out that amazing and involved story at www.monarch-butterfly.com.
A brighter future for most monarchs is dawning. If the monarch lives generally east of the Rocky Mountains, it will migrate to Mexico and hibernate in oyamel fir trees. The Michoacan Reforestation Fund and La Cruz Habitat Protection Project is replanting trees in critical highland Mexico communities where overlogging has been an issue (see www.michoacanmonarchs.org/). At the same time, the Monarch Butterfly Sanctuary Foundation is educating forest users about the importance of those trees to continuation of the butterflies and their impact on the economy (tourism, forestry, and so on) of Mexico. Support from government officials is growing.
Our western monarchs, however, continue to lose ground. Those summering west of the Rocky Mountains, will hibernate in and around Pacific Grove, and as far south as Goleta, California, in eucalyptus trees. Problems with the western monarchs, according to WSU professor David James, and other studies (google “monarchs in Washington”), are not likely in California. More likely is a lack of food the butterflies need here in order to migrate, breed and deposit eggs.
WSU professor James notes that here in the mid-Columbia region, a favored flower is that of native rabbitbrush, and more needs cultivating. There is still a need for milkweed for breeding and egg-laying, even though I-82 is his “milkweed alley.” Over the past decade and more, he has worked with prisoners from the state prison at Walla Walla, Washington, and hundreds of Tri-Cities and regional volunteers to increase numbers and prove that western monarchs migrate to California (some using Pacific Ocean winds). His group has raised and marked thousands of monarchs with tiny wing tags, but more is to be done. In June of 2019, the U.S. Fish and Wildlife Service will determine whether or not our western monarchs should be designated as “threatened.”
Want more? Google “monarchs,” then check out “The year of the Butterfly,” by George Ordish, Robert Michael Pyle’s new “The Butterflies of Cascadia,” or the “Audubon Field Guide to the Pacific Northwest.” Then think about what you or your family might do for our butterfly royalty.
[Jim’s note: this is my last Friday posting of this column! Beginning next week, the posting day changes; we will be meeting on Wednesdays! See you then…]
