Monarch migration underway; report sightings to aid conservation


Monarchs from Canada and the Midwest, including right here in Wisconsin, have begun their long journey south to Mexico, where they will spend the winter.

Dustin Boyarski captures a photo of monarchs roosting in a tree in the Town of Clayton in Winnebago County on Sept. 2.

Large groups of the butterflies often roost together in trees overnight, and this year, rainy weather and winds from the south have slowed their migration, giving people more opportunities to see these amazing overnight roosts. 

See where these roosts are being reported and help track and study the monarch migration to aid conservation efforts. Report any monarch roosts you see, as well as peak migration events (the most monarchs you see in one day), to Journey North

Journey North is a website in which citizen scientists share field observations with people across North America including migration patterns of birds, whales, butterflies and more in order to help students fit them into a global context. 

According to observations shared on the site, monarch butterflies appear to be abundant this fall.

“A major monarch butterfly migration occurred at Michigan’s Harrisville State Park on August 22nd. I have never observed so many monarchs in one day in August.” 

“Monarchs were staging by the tens of thousands on Tawas Point on August 23, 24 and 25th. With a strong south wind facing them, they wouldn’t cross Tawas Bay. I went back on August 26th and they were gone by 10 am.” Brenda McClure, East Tawas, Michigan

Pace and pathways

Monarchs rest at overnight roosts at the end of each migration day. Visitors are encouraged to click on the site's roost map and see where roosting occurred in August.

Roosts show followers where large concentrations of migrating monarchs are found. Week by week, the map will reveal the main migration pathways to Mexico and the pace of the migration.

"The pace and pathways are impossible to discern from our “All Sightings” map as you can see when you compare maps," the site points out to visitors.

Roosts raise questions

Much mystery surrounds this behavior. Roosts are difficult to study. They don’t last long and they can’t be found dependably in the same places every year.

The late Dr. Lincoln Brower shared his wonder about the roosting phenomenon: 

“If I discovered a roost, I’d pull up a chair, grab a pair of binoculars and just sit and watch! I’d try to stay hour after hour, day after day — as long as the monarchs were there. People can contribute important observations by going with an open mind and documenting what they see.”

Now in its 25th year, Journey North is one of North America’s premiere citizen science projects for children and the general public. To share sightings, visit