Post by hypanartia on Nov 7, 2015 16:21:35 GMT -8
During the last week of October, in the Big Bend NP in TX, I found groups of Danaus plexippus concentrating at dusk on the branches of a tree located in a small oasis (although no water at ground level). There are a few more trees, but only this one was selected. Surprisingly, they only rest at the branches without leaves. I saw the same behave two nights in a row, although impossible to say if they were the same individuals. I suppose they are residents, as Big Bend is out of the major routes of migration, and it is kind of late on the season. I suppose they come from far the oasis to rest, as you cannot see individuals there during the day). In the rest of the Big Bend you can see individuals moving around during the day in singles without a particular direction. It is amazing that they can found this place, at almost night, and identify themselves as conspecific. I do not see any obvious advantage for this aggregation, anyway. Note that no other butterfly species was there, no even Danaus gilippus wich is much more abundant. Do anyone knows if Danaus plexippus aggregates at night, everywhere?. I never saw something like that in Maryland, although here you have trees in top of trees and monarchs are long gone before trees lost their leaves
