University of Guelph researchers have pinpointed the North American birthplaces of migratory monarch butterflies that overwinter in Mexico, vital information that will help conserve the dwindling species.
The researchers analyzed “chemical fingerprints” in the wings of butterflies collected as far back as the mid-1970s to learn where monarchs migrate within North America each autumn.
The monarch butterfly is threatened with extinction. Here’s what you can do to help save it.
By:David Suzuki and Jode RobertsPublished on Sat Apr 16 2016 published on TheStar.com
Three years ago, the eastern monarch butterfly population plummeted to 35 million, a drop of more than 95 per cent since the 1990s. More than a billion milkweed plants, which monarchs depend on for survival, had been lost to urbanization and weed killers throughout the butterfly’s migratory range — from overwintering sites in Mexico to their summer habitat in Canada.
We needed more milkweed in the ground, quickly. But many provinces and states listed the plant as “noxious, and few nurseries and garden centres carried local “weeds.”
A lot has changed in three years. The David Suzuki Foundation launched its #gotmilkweed campaign in April 2013 to encourage Toronto residents to plant milkweed in yards and on balconies. Foundation volunteer Homegrown Park Rangers also planted milkweed in local parks and schoolyards. The Ontario government pulled the plant from its naughty list and media stories about the monarchs’ plight took flight.
Monarch butterflies depend on milkweed to survive. It’s the only plant on which monarch mothers lay their eggs and food source for monarch caterpillars. Over the past few decades, more than one billion milkweed plants have been lost across North America, largely due to widespread use of the herbicide glyphosate (Roundup) on millions of hectares of agricultural land. Planting milkweed throughout the monarchs’ migratory range is the single most important thing we can do to help them.