Are Monarch Butterflies In Trouble?

Nov 25, 2015

Monarch butterflies have long used the St Marks Wildlife Refuge as a stopover on the marathon migration to Mexico. But lately the monarchs are struggling.

Volunteers attempt to catch roosting Monarch Butterflies at the St. Marks Wildlife Refuge.
Credit Kate Payne

Monarchs are admired for their black and orange wings, and the 3,000 mile migration they make from Canada to Mexico. On cool Saturday mornings in the fall, David Cook with the Fish and Wildlife Conservation Commission spots and tags the monarchs at St. Marks Wildlife Refuge, with the help of “citizen scientists” and volunteers. The Refuge lies 30 miles south of the Florida State Capitol, and is a favorite roosting spot of the monarchs. The team prowls the coastline, spotting butterflies in cedar, palm and oak trees.

Later on, each butterfly will be tagged and released to continue migrating. The trek is not made by one generation of butterflies. Instead multiple generations flock to the same forests year after year, sometimes to the very same trees. David Cook says how this information is passed along is still mysterious.

“It’s been a huge mystery. These monarchs have never been here before but maybe their great, great, great grandparents have,” he said.

David Cook tags a monarch with a small blue sticker for identification.
Credit Kate Payne

But one thing is not so mysterious: monarch populations are plummeting. According to National Geographic, North American monarch populations have declined by 90 percent over the past twenty years. Other pollinator populations are struggling as well, most notably the European honey bee. Many cite habitat loss and climate change as the inciting incident, but Jaret Davis, a University of Florida entomologist, says a certain class of pesticide plays a role as well: neonicotinoids.

“There’s almost like the perfect chemical when it comes to your pesticides. They’re easy to apply, they are fairly long-lasting and they’re acutely toxic,” he said.

Neonicotinoids, or neonics were first introduced in the 1990s. Since that time they have become one of the most widely used pesticides in the world. Neonics are absorbed into every part of the plant: roots, leaves, pollen. Fritz Davis, author and history professor at Florida State University, says the pesticide is acutely toxic, even in trace amounts.

“When sprayed on seeds, the tissues of plants take up the insecticide and in effect render the plants themselves toxic to insects,” he said.

And while the insecticide may not directly kill pollinators, it can hinder their ability to navigate. The European Union has banned most types of neonics, and this week Quebec announced plans to restrict them as well. President Obama has also weighed in, and launched a Pollinator Task Force early this year. But critics say real progress will only come when the US follows Europe’s lead and bans the pesticide. Jaret Daniels says a lot is at risk here.

“So much of our well-being, our economy, our lifestyle, our food quality rely on these insects and their productivity,” he said.

Many scientists see pollinators as a bellwether of the overall health of an ecosystem. Pollinators play an integral role in the development of agriculture and the ecosystem at large. Last Saturday, David Cook’s team tagged 247 monarchs at St. Marks. Cook hopes the monarchs will finish the journey to Central Mexico, but there’s no guarantee. Of the tens of thousands tagged in North Florida over the years, only twelve have been found in Mexico. With a little luck, the monarchs should be showing up in the forests of Central Mexico this winter.