Date: 10/20/2021
Number: 1000
Amazing roost at the tip of Cape May. Monarchs nectarine on goldenrod before roosting at sunset in pine and deciduous trees.
[Additional information contributed by observer, added by Journey North, 10/22/21]:
We were visiting the area (Cape May, New Jersey) for some fall migration birding and heard about the roost from some other birders.
I do not know how long it had been active, but people mentioned that a couple of weeks prior, it had been quite large. Some said about 1,500 and that it had gone down over the next period of time. While we were there, the roost began increasing. The increase was possibly due to the very strong northwest to west-northwest winds that blew for the 3 days (in the range of 15-20 mph) we were there. On the morning of the 21st, the winds were more south west. We saw flying monarchs everywhere we visited around Cape May from 18-21 Oct. I believe overnight temperatures were in the mid 50s at night with very clear skies and a nearly full to full moon. During the day, temperatures were in the low to mid 70s. Apparently, based on what people told us, the roost has formed in the area in other years but never in the exact same trees. The pines were possibly pitch pines but I am not familiar with the local flora. The deciduous tree looked like a small cherry. It was only about 8 ft. In height. The roost trees were along a maintained dune access path to the beach and definitely protected from most of the wind as they were growing on the backside of the dunes.
The monarchs were on the goldenrod growing on the dunes just above the beach and (so on the front side of the dunes and “in front” of the trees) just before sunset. Some clumps of goldenrod had a dozen or more monarchs on them! There was nothing else flowering in the immediate area. We did see monarchs obtaining nectar from lantana in gardens in front of residences on the opposite side of the street during the day.
As to the number seen, the estimate originates from a very rough count of the “clumps” of monarchs perching in the several pine trees along the beach access. I counted roughly 50 butterflies in one spot and used the “area” they resided in to count the additional clumps (hope that makes sense). One estimate was of 800-900 before dark. The final estimate at near dark was of 900-1000. The photo I attached to the report shows approximately 50 butterflies so you can see what “area” I used to count. There were approximately 8 dense clumps scattered over 3-4 pine trees as well as smaller groups of butterflies between the larger “clumps”. There were about 30-40 in the deciduous tree.
Of note, we could see at least two tagged butterflies but could not read the numbers even after photographing the wing and enlarging the photo. The tag was too blurry to decipher. We “assumed” they were butterflies tagged locally at Cape May.
Cape May Point, NJ
Latitude: 38.9 Longitude: -75
Observed by: Mary Alice
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