Date: 08/18/2019

Number: 2000

I found over 2000(best estimate) of Monarch Butterflies in heavily wooded area that is located next to cornfield on on side and native prairie on the other. They were roosting in the trees. I found them about 11am. I went back in the evening around 7pm and most of them were already gone.

Editor’s note: We have contacted the observer to confirm details of this roost.

Additional comments from observer:

Date: Sunday 8-18-19 between 10:15am and 11:00 am.
I did an estimate by counting the number of Monarchs on 1 extended branch and than counting the number of branches that were similarly full on the tree. I then multiplied the amount by the number of trees that were occupied. I did not account for Monarchs that were flying overhead or outside the main roosting area.

I am not sure about the nectar source. There is a decent amount of Milkweed along the dirt road leading to the wooded area. I think there is a field of beets on the Northern side.

Temperatures: it was a chilly morning, around 55 degrees when I started my day and I was wearing a long sleeve shirt...but it warmed up just enough after I found the roost and it was over 60 degrees for sure. It was definitely cooler where they were at though and there had to be a 5 degree difference from the sunshine to this shaded area. I would say 63 degrees outside the roost and 58 degrees in the shade.

Wind direction was a breezy wind 10-15 MPH I believe out of the south. The area where the Monarchs were was almost 100% protected from the wind.

Campbell, MN

Latitude: 46.1 Longitude: -96.2

Observed by: Wayne
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