I went birding today at Valle Vista in Moraga, saw 48 species. At about 11 AM, looking west from the horse corral, over the hills, I noticed a lot of Common Ravens riding a thermal. Looking higher I kept seeing more, and more. I made several estimates, counting by groups of ten, and came up with ~70! Judging by their size, shape of tails, and vocalizations, they were all ravens. I have never seen so many at one time. After a few minutes they dispersed in various directions, and were gone.

Johan Langewis
Oakland

My sister and I were also there and witnessed this spectacle! I saw this before at Valle Vista a few years ago but above the hills across the road from the entrance.

-Melani King
Pt. Richmond