Tonight I went to the view the Purple Martin roost at its traditional spot at the foot of the Causeway in Metairie, viewing from the west side. The numbers appeared to be up from the last several visits I have made (going back several years)- I estimated the number of birds visible in the air at peak tonight to be 5-10,000. Based on my detailed analysis of this roost in 2015, the number of birds actually present (more accurately counted at morning departure when they leave in a steady unidirectional stream) is probably thousands more than that.
Numbers of birds appeared at 8:10, roost entry began at 8:20, and entry was virtually complete by 8:28 pm. Tall clouds (and perhaps the much-heralded Saharan dust incursion) to the west prevented there being any sunset glow. There was nobody else at the roost viewing spot, so no covid concerns (it was also easy to maintain distance from users of the bike path while walking to the viewing spot from where I parked on the east side of Causeway near Vets of America).
The closest 100 birds were all female/immature types, consistent with the absence of adult males that I have noted in years past.
I was surprised to see 3-4 Mississippi Kites still soaring along the massive glass face of the Lakeview Building when I arrived, as described happening earlier in the day in years past. I don't recall them previously doing it so late in the evening. One did make a maneuver to catch something, but they mainly were just soaring, their reason for being there is still (to me) a mystery. Always cool to see them soaring along the glass, mirrored by their reflection.
Here is a tape of some of the roost entry
The roosts usually peak around July 1.