David Suzuki’s #gotmilkweed campaign is helping the Monarch butterfly

This week, the David Suzuki Foundation launches its third annual #gotmilkweed campaign to highlight the plight of the still fragile monarch butterfly population.

“Monarch butterflies had a good winter but they remain perilously close to extinction,” says Jode Roberts, manager of the David Suzuki Foundation’s Got Milkweed campaign. “Planting milkweed and other pollinator-friendly plants in our gardens, schoolyards and parks is the best way citizens across the country can help bring them back.”

The #gotmilkweed campaign asks supporters to plant milkweed seeds and plants (both are available for purchase through the Foundation’s website) as well as to sign on to the Monarch Manifesto, involving commitments to grow milkweed in one’s yard or garden, to report monarch butterfly sightings and to refrain from pesticide and herbicide use at one’s home.

“Milkweed is the only plant that monarch butterflies lay their eggs on and is the primary source of food for monarch caterpillars,” says Roberts. “Scientists have identified milkweed planting as the most important action people can take to help support threatened monarch populations.”

A recent study reports that the Eastern migratory monarch population declined by 84 per cent between the winter of 1996-97 and the winter of 2014-15. It is notoriously difficult to count individual monarchs and thus scientists use geographic area to estimate population sizes, with the 2014-15 population figured to be about 2.8 acres in size (the population was at its lowest a year earlier in 2013-14 at 1.7 acres). Scientists estimate that a single snowstorm in early March of this year killed up to 11 million monarchs.

The study determined that there is a “substantial chance” (11 to 57 per cent) of quasi-extinction of the monarch over the next 20 years. Quasi-extinction marks a species population small enough that any chance of recovery is impossible.

“Because monarch numbers vary dramatically from year to year depending on weather and other factors, increasing the average population size is the single-most important way to provide these iconic butterflies with a much-needed buffer against extinction,” says Brice Semmens, the study’s lead author and scientist at the Scripps Institution of Oceanography at UC San Diego.

Experts say that damage to monarch butterfly populations can be traced to a number of factors, the most notable one being a loss of breeding habitat, chiefly through the use of herbicides which destroy the milkweed plant. Estimates say that about half of the milkweed available to butterflies within North America has been eliminated since the decline its population began 20 years ago.

The United States Fish and Wildlife Service, along with promoting a Monarch Joint Venture conservation plan with aims similar to those of the Suzuki Foundation’s initiative, is currently considering a petition to protect monarchs via the US Endangered Species Act. So far, the Government of Ontario has listed the monarch as a Species of Special Concern.

A 2013 study found that general support for conservation of the iconic butterfly is high, at least in the United States, where survey data suggests a willingness to commit up to (U.S.) $6.5 billion to the task.

According to the Suzuki Foundation, the #gotmilkweed campaign has so far resulted in 10,000 plantings of milkweed in the Toronto area alone and 11,000 pledges to the Monarch Manifesto.

Below: The David Suzuki Foundation: Got Milkweed?

More Cantech Science