For night between Oct 7 and 8. The number I entered is what I actually saw. Total is really much higher. An hour or so before sunset I saw a few Monarchs already flying near trees that are typical roost sites. But most Monarchs were still on flowers at sunset. One-half hour after sunset none were obvious on flowers, but there was no obvious mass exodus either. I did find some perched in larger Live Oak and Ashe Juniper trees, but not enough to account for all that were feeding. I did not check every tree. I found a couple roosting individually on tall forbs. Wind had gone calm at sunset and remained so until sunrise when it rose quickly. So they all "roosted" if I define roosting broadly, as anything that does not involve flying, eating or reproducing, ignoring whether they aggregated.
The image shows a small roost still under a large Live Oak at 8:30 the next morning (Oct. 8). A few seconds after I took this picture they all flew off simultaneously.
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