Yellow-angled Sulphurs at Progreso Lakes, 9-13-17

Mike Rickard has seen about a jazillion Yellow-angled Sulphurs this year while it's been eons since I've seen one.  But while I was birding in the yard this morning I saw a large pale sulphur that seemed to have a slower, stiffer wing beat and I thought.....hmmmmm.  That could be an angled-sulphur. Turned out it was a female Yellow-angled Sulphur.  A first for our yard.

Then it seemed to disappear and after lunch I checked the purple duranta again and the Yellow Angled-Sulphur was back.  Except it was a male!

Maybe the shift of winds to the south had something to do with it.  Our normal SE wind blows from Progreso, Mexico across the Rio Grande where there is not a lot of butterflies.  But a south wind blows across a couple of hundred acres of Lower Rio Grande NWR land