[EBB Sightings] Purple Martin - San Leandro Reservoir (Contra Costa County)

This noon I saw two Purple Martins while standing on the Bridge at Upper San
Leandro Reservoir, reached from the Valle Vista staging area.  They briefly
circled over my head in the company of a much smaller Barn Swallow, then
disappeared upstream.

I'm not used to seeing these birds in the Bay Area, but last month was
pleased to see two at Five Brooks in Marin county, where I know they have
nested in past years.

This is a new bird for the CCO year list.