Good News on Monarch Butterflies, But Don’t Get Too Excited
So the good news is that there are a lot more Monarch butterflies roosting in Mexico this winter than there were a year ago. Monarch populations are measured by the size of overwintering colonies in the mountain forests of Michoacan. This year, they are covering a little over 6 hectares (or about 15 acres), a 144% increase from the 2016-17 winter, when just 2.48 hectares were occupied.
To me and many other gardeners, it did seem like there were more Monarch in the garden last year – now this perception has gotten some validation. This year’s numbers are the highest they’ve been since the winter of 2006-07, according to the above graph from Monarch Watch.
Unfortunately, one year does not make a trend, and the trend still looks negative over the longer term. Scientists quoted in a New York Times article noted that this year’s numbers are mainly due to 2018’s favorable weather conditions. The Monarch population could take a big hit if the weather turned less hospitable.
Still, we should never dismiss good news, especially these days. Monarch Butterflies are still imperiled by habitat loss, insecticides, etc. The work of conservation by government, non-profit organizations, and individual gardeners (plant more Milkweeds!) should continue and intensify. The New York Times quotes University of Guelph ecologist Ryan Norris on the new numbers: “It buys us time, but that’s all it does.”