No-so-good monarch news

Just in case things aren't depressing enough right now:

The number of monarch butterflies that showed up at their winter resting grounds decreased about 53% this year, Mexican officials said Friday. 

Some activists called the decline “heartbreaking," but the Mexico head of the World Wildlife Fund said the reduction “is not alarming.”

WWF Mexico director Jorge Rickards said the previous year's large numbers were "atypical" and the monarchs had returned to their average population levels of recent years. 

The government commission for natural protected areas said the butterflies' population was “stable,” even though they covered only 2.8 hectares (6.9 acres) this year. That was down from 6.05 hectares (14.95 acres) the previous year. Because the monarchs cluster so densely in pine and fir trees, it is easier to count them by area rather than by individuals.

Not everybody agrees with Rickards' assessment, however.

In contrast to Rickards' view, Tierra Curry, a senior scientist at the Center for Biological Diversity, wrote that “scientists were expecting the count to be down slightly, but this level of decrease is heartbreaking."

"More protections are clearly needed for this migratory wonder and its habitat,” Curry wrote.

Environmentalist and author Homero Aridjis said that “the decline of over 53% of populations in the butterfly reserve is worrisome, above all because of the effects of climate change on the migration route and on the wintering grounds in Mexico.”  

Aridjis said crime and deforestation in Mexico is also a cause for alarm. One butterfly activist and a part-time guide in the reserve were murdered earlier this year.

Monarch Watch director Chip Taylor had predicted that the overwintering population would be lower this year than last, based on the following factors:

Population growth
• Less than optimal egg distribution in March and April
• Later recolonization of the Upper Midwest
• Low monarch production in Iowa and maybe western portions of the upper Midwest
• Lower summer temperatures than in 2018 

Migration
• Late migrations are associated with lower numbers reaching Mexico
• Droughts are associated with lower numbers reaching Mexico
• High numbers in the northeast do not translate to high overwintering numbers
• Northeast butterflies take too long to migrate southwest

Even so, Taylor expected the overwintering population to occupy 4.7 hectares, which means that the actual numbers were worse than his prediction.

As good as last year's numbers were, they very clearly appear to be an outlier in the Monarch Watch graph:

The bottom line: the monarch butterfly migration continues to be threatened by herbicide and pesticide use along the migratory path, illegal logging in the overwintering region, and climate change in general.

Since people have a lot more time to do things like gardening these days, my suggestion is the same as it's always been: plant that milkweed.