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Not yet gone forever, but Monarchs are missing
Monarch Butterflies are icons of my youth. They were so common in Nebraska where I grew up. Their wintering place, in the Oyamel fir forests of the Mexican Sierra Madre’s, was only discovered in 1975. I remember well the National Geographic issue that announced this amazing discovery. The photographs were so astonishing--it was the kind of story that everyone talked about and when we did we smiled with excitement in awe of such a wonder. http://texasbutterflyranch.com/2012/07/10/founder-of-the-monarch-butterfly-roosting-sites-in-mexico-lives-a-quiet-life-in-austin-texas/
Monarch populations have been on a steady decline ever since, but most dramatically since the beginning of this young century. And last year was quite a disaster. See this graph from Monarch Watch: http://monarchwatch.org/blog/2014/01/monarch-population-status-20/ The columns represent the number of hectares the monarchs occupy over the winter. The butterflies can’t be counted individually, so their population is measured by the amount of canopy covered while they huddle together in the winter for warmth. In 2011-12 they occupied more than 7 acres, in 2012-13 less than 3 acres, and this past winter .67 hectares or just a tiny bit more than 1 1/2 acres.
In March, the monarchs leave Mexico and move north via successive generations. The first stop for most of them is in the vast state of Texas. The monarchs need to find milkweed on which to lay eggs so the next generation will continue the northward flight. Texas has had an especially cold winter this year and some reports say not a lot of milkweed is around yet. This website tracks the journey of the Monarchs: http://www.learner.org/jnorth/monarch/News.html
The butterflies that hatch in Texas will travel further north--the farm belt country is where they will head in search of milk weed to lay their eggs. The milkweed story there is the main key to the disaster. You can easily find numerous sources that will tell you about it, but here's one statement from Dr.Lincoln Brower, on the Monarch Butterfly Journey North website: "The evidence we have strongly points to one main cause of this decline: the current soybean and corn crops are genetically engineered to tolerate heavy doses of herbicide that kills all competing plants, including milkweeds. Growing virtually unlimited genetically modified plants doused with poisonous herbicides is starving the rest of nature's food chains, including that of our beloved monarch butterfly as well as pollinating insects in general." http://www.learner.org/jnorth/monarch/spring2014/update021314.html
It takes 3-4 generations to reach their most northern destinations in the US and Canada. This photograph of a first instar monarch caterpillar (above) is deceiving--as the creature was barely 1/4" long. Imagine how many of these need to survive in order to produce the next viable adult generation.
This is a 4th instar monarch caterpillar. The process from egg to butterfly is weather dependent, but on average it takes about a month to go from egg to adult. It can take 5 to 10 days after the egg is laid for the first instar caterpillar to hatch. That caterpillar will reach the fifth instar in about 10-14 days. It’s the fifth instar that creates the chrysalis. Finally, in about 10 to 14 days more, an adult butterfly will emerge from the pupa or chrysalis.
Three Monarchs in a milkweed field - Tamworth, NH
In August of 2012 my husband and I saw dozens of migrating Monarchs flying and feeding in a small milkweed field in Tamworth, New Hampshire. It was a bright sunny day and we were exhilarated by the sight! We made friends with the people who own the land. We received a letter this winter with news that they saw only one Monarch the entire summer.
The return fall migration is accomplished by just one generation: that means tens of thousands of individual adults fly several thousand miles to their winter roost in Mexico. The journey can take up to two months.
For an in-depth look at the current state of monarchs, listen to this talk by Dr. Chip Taylor, founder of Monarch Watch: http://www.youtube.com/watch?v=fh42KGh-TkE
Keywords: caterpillars, lepidoptera, milk weed, monarch butterflies
Oh, LInda, wonderfully written (and photographed.) I seached for Monarchs (and other butterflies) last summer and was gravely disappointed for the most part. Butterflies can bring such joy to heart and soul...a wonderful Native American legends tells of the creation of butterflies as inspiration to get the 'first' children (babies) of the world up and walking.
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