Millions of monarchs on way to Mexico stop in St. Marks

With pesticides on the rise, many butterflies may be left with less food

ST.MARKS, Fla. – Millions of majestic monarch butterflies are on their way to Mexico. And year after year, one of their favorite resting places is in St. Marks along the Big Bend of Florida.

Normally, the monarchs live just a month, but a hormone kicks in when the temperature drops, extending their life to seven or eight months, making the migration to Mexico possible.

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The butterflies attracted two Polk County high schoolers. They've been coming since 2012, conducting a science experiment: measuring a protozoan that caterpillars ingest from milkweed and carry into adulthood as a butterfly.

"A lot of farmers are applying more pesticides and everything to their crops and killing milkweed because it is invasive, so when there is no milkweed, they have nowhere to go, nowhere to eat," said Taylor Obyrne, a junior at Lakeland Christian High School. 

"And without the small areas of the food web and without pollination stuff, we’re not going to have what we can, so we need to do what we can to save our environment," Lakeland Christian student Victoria Benson said. 

Cheryl Lachance, a birdwatcher, said this year’s crop is really small.

"See the canopy on this one here where you have a few of them, times it by about 20, 30," Lachance said. 

The butterflies return in the spring, lay their eggs and then die, only to leave next year's migration to a new generation of monarchs.

The butterflies normally hang around the wildlife refuge through the middle of November, depending on the temperature. When they leave, they will follow the gulf coast into Texas and then Mexico.