Date: 09/05/2019

Number: 150

There were about 150 Monarchs roosting on the north side of our walnut grove. I tagged 65 of them between 3 and 5 PM. The wind was from the north and the butterflies were gone the next day.

Editor's note: contacted observer for more details on this sighting

I have been checking the grove of trees for several days. I check in the morning about 9, again around noon and later in the afternoon usually between 3 and 4. Last Thursday (9/5/19) I had done the first 2 checks and seen 5 or 6 Monarchs. When I checked at 3, it was immediately obvious that there were more.

The Monarchs roost on the north and south side of a grove of walnut, ash, choke cherry trees with evergreen trees and dogwood shrubs in the interior of the grove. Thursday afternoon I skirted the perimeter. There were several large clumps of Monarchs. I counted 2 of the clumps at 28 and probably 36 (due to some taking flight, it had to be a guess) I multiplied the number of clumps I had seen by 25 and reported at least 150.

The overnight temperatures were in the 50s.

I am never sure about the Monarch's choice of roosting sites. Because there are many trees and micro-climes among and between the trees, it is hard to say, but I often find them on the south side of the trees, but the perimeter and the roost would be described on the north side. There is a soybean field directly to the north and the Monarchs come from the north above the soybeans so the trees are the first they encounter. If we have a south wind while they are here, they flutter about, sometimes nectaring on Black-eyed Susan blooms, sedum, phlox. But they roost much more frequently than they nectar.

There were many, many more Monarchs yesterday (9/11/19). I completed my tagging and took the attached picture.

Dysart, IA

Latitude: 42.2 Longitude: -92.3

Observed by: Cathy
Contact Observer

The observer's e-mail address will not be disclosed.
Contact will be made through a web-based form.