Noticing more monarch butterflies? You're not alone!

A banded monarch (photo courtesy of Kirk Larsen)

Over the past week, many Decorah residents have noticed more monarch butterflies than we typically see.

Dr. Kirk Larsen, Head of the Luther College Biology Department, has also "observed a good population of monarch butterflies this summer." During the summer, Larsen will often count local butterflies, so he's familiar with recent population levels.

He conjectures that a "higher starting population at the overwintering sites in Mexico last year," plus wet summer weather in the upper Midwest, made for good conditions for monarchs and their food source, milkweed. When milkweed growth is low—like in the dry summer of 2017—it "can hurt monarch abundance," said Larsen.

Larsen expects the concerted effort, both locally and nationally, to preserve and increase milkweed is having an effect on monarch populations. However, said Larsen, "We won't really know if there are more monarchs until the overwintering population is quantified in Mexico again this winter."

Larsen will be hosting a monarch migration banding event in early September (exact date TDB). A number of monarchs will be tagged with a small tracking device, and Larsen and his students will record the migration patterns.