Good News on Monarch Butterflies – For Now
So the numbers are out on the eastern Monarch population in Mexico for the winter of 2015-2016, and the news is good. The Monarchs roosting in pine forests occupied a total of 4.01 hectares (a little under 10 acres) this year, more than three times last year’s 1.13 hectares (less than 3 acres). The population nadir occurred in 2013-2014, when Monarchs covered just 0.67 hectares, about 1.5 acres.
The 2015-2016 numbers were just released today by the Monarch Joint Venture, a partnership of US government agencies and environmental organizations.
Here’s a chart showing the winter Monarch population since 1994.
The Monarch recovery is still very fragile. Research indicates that a population covering 6 hectares is needed to bounce back from sudden population declines caused by bad weather or disease. Moreover, this winter’s population is just a small fraction of the Monarchs overwintering in 1996-1997, when they covered over 18 hectares.
Good weather and habitat restoration both seem to have contributed to the recent increase in the Monarch population. A great deal more still needs to be done, though.
On an individual level, I take this as a reason to plant MORE MILKWEED (Asclepias) in home gardens, starting with my own. I am actually waiting for a shipment of a Sullivant’s Milkweed (Asclepias sullivantii) from Prairie Moon Nursery. This species is supposed to be similar to Common Milkweed (A. syriaca), with round umbels of fragrant pink-lavender flowers – but much less aggressive.
And I noticed that Prairie Nursery is selling two new Milkweeds this year: Showy Milkweed (A. speciosa) and Poke Milkweed (A. exaltata), a taller Milkweed that can grow in shade.
Another aspect of the problem is the use of insecticides, particularly neonicotinoids. Any gardener who wishes to help Monarchs and pollinators generally should refrain from using these toxic products. However, it will require government action to substantially reduce the application of the most harmful insecticides.
To that end, it was frustrating to read of a report from a UN-affiliated agency on the status of pollinators. The report seemed to treat the complexity of the threats to pollinator populations as a reason to avoid calling for strong action on pesticides. A spokesperson for Bayer, the company that manufactures neonicotinoids, was pleased.