Monarch butterfly numbers drop by 'ominous' 59% – How you can help.

As late winter eases into early spring, I’ve been seeing waves of migratory birds in southern Ontario pushing northwards:  waterfowl, blackbirds, some birds of prey.  But one migrant, not a bird, but the Monarch Butterfly, is just now leaving its winter home in Mexico.  They leave occupying less area – under 3 acres – of oyamel fir forest in Mexico’s central highlands than ever before recorded.

Numbers fluctuate, but some 10-100 million Monarch Butterflies occur in the central and eastern portion of their North American range.  (A much smaller population lives from southwestern B.C. to California.)  Counting those butterflies is difficult – I have seen the fir trees in late February in Mexico, drooping to the ground with the weight of hundreds of thousands of butterflies, looking from a distance like shimmering orange snow on the fir boughs.
One way to estimate their numbers is to simply measure the area of forest in which trees are found with monarchs.  As the graph shows, where for years some 5-10 hectares of forest were occupied, this past winter only 1.19 ha hosted monarchs,  a startling drop of about 60% over the previous year.  The story was big news over the last week.

There are multiple causes for the decline:  loss of the monarch’s only host plant, milkweed, from herbicide spraying of corn and soy farm fields in the U.S. and Canada; illegal logging in parts of the oyamel fir forest; heavy ecotourism in Mexico; probably climate change in the breeding and wintering grounds.
My earlier blog details the monarch’s life cycle and connection to Canadian scientists, as well as a wonderful documentary of their life and plights, Four Wings and a Prayer.
Though over a hundred species of migratory birds, along with whales, bats and marine turtles, share North American land- and sea-scapes for their breeding grounds and wintering areas, no species symbolizes the ecological connection among Canada, the U.S. and Mexico as vibrantly as the Monarch Butterfly.  It became a symbol for many things tri-national on this continent.   Just as the loss of the Giant Panda would be a tragedy for China (and WWF, given our panda logo!), so would conservation prospects be set back enormously in North America by loss of the migratory wonder of the Monarch Butterfly.
So, what can you do?
Two easy steps:  keep some milkweed in your backyard, cottage or farm and enjoy the butterflies whose host plant you maintain.  I do this and it’s fun to see Monarch females lay eggs there every year.  Second, participate in Earth Hour, turn out your lights, and vote by candlelight for society to tackle climate change, which threatens monarchs in their summer and wintering habitats.  And after you’ve done taken these two steps, tell your federal MP you’ve taken action and you expect the federal government to do so, too!