Monarch butterfly update: things are getting worse

Not good news:

The 2023-2024 census of monarch butterfly numbers found one of the smallest annual populations of the insects at the overwintering sites in Central Mexico.

The World Wildlife Fund-Mexico and its partners released the data last Wednesday, which highlighted that the presence of eastern monarch butterflies decreased from 2.2 to 0.9 hectares. According to the news release, this is the second worst year for monarch butterfly sightings with the 2013-2014 census holding the lead with 0.67 hectares. 

“Fewer monarchs hibernating in their traditional forest habitat in Mexico greatly concerns all of us. It’s critical that all communities, governments, non-governmental organizations, scientists and others continue to strengthen our conservation and protection efforts to support the monarch’s unique migration,” said Jorge Rickards, general director of World Wildlife Fund-Mexico in the news release.

This isn’t the first time the foundation found a decline in monarchs, last year’s data showed a 22% decline in the butterfly population, based on the number of acres the insects occupied in Mexico. Factors contributing to these butterflies' decline include herbicide application to U.S. breeding grounds, drought and forest degradation.

Here's the updated overwintering graph from monarchwatch.org. It's pretty grim:

monarchwatch.org     

Back in 2022 I noted that the overwintering monarch population seemed to he holding steady in the 2-3 hectare range for the past several years and expressed hope that it meant things had stabilized. Unfortunately after this past winter that no longer appears to be the case.

According to Monarch Watch founder Chip Taylor, the migratory monarch population is took a big hit from last fall's drought that extended from Oklahoma into central Mexico. This meant fewer flowers and therefore less energy-providing nectar that fuels the insects' migration and sustains them through the winter.

While monarchs are resilient insects, they're going to need more milkweed plants to lay eggs and more nectar plants to feed them in order for their population to recover from this past winter's low. So please plant your gardens accordingly. I also wonder if this news is what finally persuades the US Fish and Wildlife Service to declare the monarch an endangered species.