I saw several dozen roosts yesterday, 9/9/2018 at Ottawa National Wildlife Refuge along the SW shoreline of Lake Erie. We were in the midst of a nor'easter so the Monarchs that had flown over Lake Erie had no choice but to roost.
There were many independent roosts, but outstanding were the wooded stretches along the dike roads that held mega roosts with strands of smaller roosts that continued for many yards. 6 different dike roads were involved. I estimated at least 2 million Monarchs. It was a phenomenal day.
I was at the refuge the day before (Saturday 9/8/19), and saw NO roosts. However, there were reports of some smaller ones. So, in 24 hours, the roosts went from some, (I think it read a count of 1,000 individuals or more) to the exponential numbers that I saw.
I would guess there were 50 roosts (several dozen). I stopped counting the roosts after the first 12 and figured I was less than 1/3 the way through the refuge auto-tour. The bulk of the roosts were further north which was the last 2/3s of the tour. Roosts were spread out & thin for the first 1/4 or 1/3 of the tour. ( See map. Understand, the start of the auto-tour is at the southern edge off Route 2 and swings west/north/east back and forth thru the roads, then the final western stretch is basically just off the shoreline to the exit.)
The massive roosts were at one point 100 ft (approx??) off the lakeshore that had pounding waves and 35mph+ sustained winds. All the monarchs were on the leeward side of the woods that sat between the road and the shoreline. A perfect scenario for them to find shelter immediately coming in off the lake.
Weather notes for 9/9/2018: 2 pm-4:15 pm is when I saw them. 63F 100% sky cover 4:15pm raining and I left at 4:30pm. Winds over the lake were at least NE 35mph sustained. Winds inside the refuge ranged from NE 10-25 mph depending on location. I believe the overnight temps were in the mid-high 50F s with rain in the am through 12pm.
There are no nectar sources in that area of the refuge but along the southern refuge roads were these sunflowers - I do not know the common or Latin name. (The photo taken 9/8/18 along a southern road.) There were several large fields in full bloom waiting for them! Also, there was some goldenrod but not nearly as much as the sunflower.
I have counted Butterflies for the OH Leps long term study program for over 14 years including Karner Blues and just this year, the Dakota Skipper in MN, for The Nature Conservancy as a volunteer so I knew on Sunday I needed to photo & write down as much as I could before it escaped me. I took over 400 photos in those 2 hours, wonder if any of those monarchs have a tag on them? Finding Waldo? More so, Tuesday (yesterday, 9/11/18), we had mostly sunny skies and 74F dry. No doubt the monarchs found their way to the nectar fields not long after taking flight in the morning after warming.
I have over 400 photos and posted 50 on Flickr. Please email for more photos or info. Also see Facebook group - Butterflies of the Eastern United States post by myself, Jackie W Riley, The Ohio Lepidopterists.
Latitude: 41.6 Longitude: -83.2
Observed by: JACKIE
The observer's e-mail address will not be disclosed.
Contact will be made through a web-based form.