For the past several years, it seems that the only news we heard regarding monarchs was discouraging. Consequently, I was elated when Mexican butterfly experts recently reported that 35 percent more monarchs arrived in the pine and fir forests in November 2021 west of Mexico City which serve as their winter home than in 2020.
Interestingly, these estimates are not determined by counting individual butterflies. Instead, they are based on the total acreage occupied by monarchs roosting in massive groups on the limbs of trees in this precious habitat.
According to the Mexican government’s Commission for National Protected Areas, this past winter monarchs roosted on seven acres of forested habitat located high in this critical high mountaintop habitat. Although this doesn’t sound like much during the winter of 2020-2021 monarchs roosted on only 5.2 acres.
Gloria Tavera, the regional director of Mexico’s Commission for National Protected Areas, reports that in 2021 monarchs began departing for their summer breeding grounds in February. For reasons that are not understood, these colorful orange and black butterflies left much later this year (they typically leave in March). According to Tavera, “We still had butterflies in April.” She went on to say, “It remains to be seen in next year’s figures whether that strategy worked for them.”