Huge roosts in Indiana, first reports from Point Pelee, and a western update

Roost reports move south

By Jacob Swanson, Journey North program coordinator

With the last wildflowers of the year blooming and the chilly fall days starting up, monarchs are on the move, and soon, a monarch sighting will inevitably be our last sighting of the season. Some of us have been lucky to enjoy watching monarchs on their migration, including seeing roosts as monarchs head south.

I was fortunate enough to see my first roost of the season on Sept. 2 thanks to a Journey North volunteer, Anna-Lisa, who first reported it on Aug. 26. The roost wasn’t quite as big when I saw it as when Anna-Lisa first reported it, but it was still interesting to see the monarchs fluttering in across the Pheasant Branch Conservancy prairie in Middleton, Wisconsin, just before sunset.

Most of the Upper Midwest’s pins on the fall roost map appear west of the Minnesota-Wisconsin border, with the Gopher State busy in late August.

In Minneapolis, Helen reported four on Aug. 29, the same night that Jennifer saw an estimated 40 to 50 in Stewart.

Sadie in Huron, South Dakota, reported 50 monarchs in a roost on Sept. 2. In Hartley, Iowa, Bruce reported 12 on Sept. 1, writing the following:

“Had about 12 in the yard this evening, but only a couple sitting together…one couple did have 3, but one flushed as I got too close. Had a small rainbow in the east as a monarch flew past. High hopes for tomorrow night - cold front coming!!!”

Nebraska’s first roost report, from Ronnie in Aurora, Nebraska, came on Sept. 5. In Linwood, Nebraska, north of Lincoln, Jake reported hundreds, "if not close to 1,000 monarch butterflies" arriving to roost in the bur oak trees.

Moving to the eastern Great Lakes, we’ve received roost reports from Ontario, Illinois, Ohio, and Indiana, including some huge reports from Indiana.

Evan in Edgerton, Indiana, reported 3,000 monarchs on Sept. 7, accompanied by an incredible photo of monarch butterflies filling the skies. Those monarchs will be filling Mexico’s skies in about two months.

Mike at Midewin National Tallgrass Prairie in Illinois has been reporting roosting monarchs since Aug. 26. Reports started in the single digits, but increased in early September. On Sept. 2, the number was 30 in one common hackberry tree.

In Wilmot Creek, Ontario, Sarah reported 25 in an evergreen tree on Aug. 30. We also received our first reports from Point Pelee National Park in Ontario on Sept. 6; Point Pelee is typically an important resting spot for monarchs before they cross over Lake Erie.

Laura writes frequent updates from Point Pelee, writing the following on Sept. 6:

“Groups of Monarchs and singles were located in numerous trees in the tip area on the East Beach, with the biggest grouping being 13. A few more roosts were discovered in the shuttle loop area. The biggest cluster was 30. A few more individuals were observed in the Sparrow Field area, roosted or nectaring in the same locations as Friday evening. The count there was approximately 8. The majority of Monarchs were observed on the East Beach. Many were at eye level or just above. The highest individuals were located a few meters up. Monarchs were located on Wild Grape, Virginia Creeper, Hackberry and Mulberry, all with eastern exposure. One female with a damaged forewing, the others were all pristine."

If you see a fall roost, let us know! Fall roosts can be anywhere from a couple of monarchs to hundreds. Roosts may take place over multiple nights. If you see a roost taking shape after already submitting a report, you can still report it each time you witness it.

Not done breeding (yet!)

We’re still receiving some reports of egg-laying, even from the same states where roosts are being reported. In Glendale, Wisconsin, Steven reported one egg on swamp milkweed on Sept. 2.

In Rushville, Indiana, Dena reported eight eggs on Sept. 1 on “the last of the milkweed.” Jaclyn in Marshall Township, Pennsylvania, reported one egg on Sept. 2 on “a very dry milkweed leaf.”

Egg sightings were more common a little further south. Sandra in Mounds, Oklahoma, reported 30 on Sept. 2:

“Watched a fresh-looking female Monarch laying eggs on Asclepias viridis plants growing in our wild area. A quick check of a small portion of the milkweed plants revealed 30 eggs. I am sure there are many more.”

Since the calendar flipped to September, we’ve also received at least one egg report in Florida, Arkansas, West Virginia, Georgia, Texas, North Carolina, Missouri, Illinois, Virginia, Kansas, Tennessee, Ontario, Colorado, and Oregon, as of writing.

These eggs, as well as larvae still in development, will be in a race against the seasons, as they’ll need to develop while there’s still nectar available, which they’ll need as adults to power their travels south. Still, there’s time. 

Last year, the first fall frost in Glendale, Wisconsin, was on Oct. 12, according to the Old Farmer’s Almanac. That gives Steven’s egg over a month to develop into an adult. Development slows as temperatures drop, but there’s still a chance for these eggs.

Western monarch update

By Gail Morris, Southwest Monarch Study coordinator

Monarch movement is now reported throughout the northern half of the West, and their signature directional flight is expanding. Rabbitbrush and key fall nectar resources are vital to refuel migrating monarchs on their long journey to the overwintering sites.

Recent Sightings

Sightings are also increasing in California and the Southwest, with monarchs reentering the lower deserts for the first time this fall.

Robin in Syracuse, Utah, reported one monarch on Aug. 31, writing, “This active butterfly really enjoyed the flowers in my yard. It would eat, fly over the fence, and return for more for about an hour's time.” 

In California, monarchs also appeared. Bob in Ukiah saw “Cosmos in full bloom and monarch lingering to feed,” and Patty in Grass Valley saw several monarchs in the area on Sept. 5.

Catherine in Prescott, Arizona, saw her first monarch of the season on Aug. 30, writing, “She was nectaring on Arizona Milkweed, A. angustifolia, and then started to lay eggs. After she nectared on Gregg’s Mistflower for 30 minutes.” 

Marceline was visiting the White Mountains in Arizona on Sept. 2 and stopped at Pinetop-Lakeside to look for butterflies. “Saw three monarchs today in the White Mountains at Woodland Lake Park in Pinetop-Lakeside," Marceline wrote.

Diana in Tucson saw her first monarch of the season on Sept. 1, writing, “Monarch patrolling and nectaring on Gregg’s Mistflower in my backyard monarch waystation."

Reports from the field

Monarchs are anecdotally reported in growing numbers around the West as the migration window nears in California and Arizona.

Diana Magor – Santa Cruz, California:

“More adults, larvae, and eggs are being seen in Santa Cruz over the last two weeks. It isn’t known if all of these are from local gardens, but I know some are, as I met a woman who has counted over 75 chrysalises and several adults and caterpillars in her garden with showy milkweed, and I have also heard from a couple who have about 100 monarchs. Yesterday we found 17 larvae, mostly second instars, and 18 eggs in my garden, where females have been ovipositing for several weeks. Most other larvae have been taken by the invasive European paper wasps (Polistes dominula), and some by spiders. My nectar garden has completely filled the space I was granted, and is being visited by many insects and hummingbirds. Two monarchs visited it yesterday.”

Monarchs in the desert

We’ve monitored monarch movement in the lower deserts of Arizona and parts of California since 2007.

Typically, monarchs are totally absent when summer temperatures soar above 105°F in early June, then they return in early September with cooler days. These early fall monarchs arrive laying eggs on desert (rush) milkweed, usually in bloom from the summer monsoon rains. But the last two years, monarchs were absent in this early September period as record heatwaves seared the region with temperatures over 110°. 

When they arrived in mid-October, they were small and breeders rather than the typical large, colorful, migratory monarchs we usually see. What would 2025 bring? The last two weeks saw monarch reports appear from the White Mountains in northern Arizona and Prescott. After negligible sighting reports in recent years, this gave us hope. Our weather for the region was more favorable in the desert Southwest this year. In late August, a short heat wave dissipated with the return of lower 100s and upper 90s blanketing the area after a brief late-season monsoon rainfall. 

Then, on Sept. 5, my husband, Bob, called from the back of the house, “I think there is something you want to see out back!” As we looked out the window together, we saw bright orange wings fluttering around the Asclepias subulata in flower. To our surprise, our first monarch of the season was right in our backyard! It’s early, but her appearance was a harbinger of the season if the temperatures stay in their preferred range and her offspring join the migratory generation shortly. Just a few days earlier, Diana in Tucson spotted her first monarch nectaring on Gregg’s mistflower.

We’ll be looking for reports on other desert dwellers over the coming days. 

Monarch and milkweed sightings needed

Seeing monarchs? Your sightings help us present a balanced and accurate report of where monarchs are appearing each week. Report adult monarchs, eggs, and larvae to Journey North. Your detailed description of what you see can include, but is not limited to, the monarch’s gender and activity. If known, include the type of flowers if they are nectaring on or milkweed type if laying eggs. Photos are encouraged and welcomed with all your reports.

Gail Morris is the Coordinator of the Southwest Monarch Study (www.swmonarchs.org). She is also a Monarch Watch conservation specialist, the vice president of the Central Arizona Butterfly Association and participates in several western monarch working groups. The Western Monarch News is based on comments provided to Gail Morris. We hope to increase the number of sightings and therefore photos and comments entered into Journey North. We rely on the volunteers who communicate regularly with Gail and who agree to participate in our effort to increase awareness of the population of western monarchs. You can reach her at gail@swmonarchs.org