Date: 1/19/26 10:40 am From: Ethan Monk via groups.io <z.querula...> Subject: [EBB-Sightings] Herring Spawn and misc.
This morning at about 8:45 AM I scoped Brooks Island and noticed what was evidently a herring spawn occurring in the eelgrass beds behind (on the south side of) the island . I estimated 3000 Double-crested Cormorants, 400 Brandt's Cormorants, lots of diving ducks and gulls, etc., many visibly pulling herring out of the water. Nothing unusual, but I only had about 35 minutes to spare. These numbers of Brandt's Cormorants are indicative of herring presence, and you only see large numbers in Contra Costa County, in my experience, at herring runs. Typically this species is scarce and vastly outnumbered by Double-c Cormorants e.g. on Jan. 8th of this year, I estimated 2800 Double-c to 20 Brandt's at this location. Herring runs are typically monitored pretty heavily by from-shore fishermen, but the location on Brooks Island is--obviously--not accessible to them. So no idea how long this spawn has been going on for. It's possible they were just starting, or possibly winding down... but I *felt *like it was not winding down. Earlier this morning I was at Pt. Isabel, where a quick scan of the bay revealed significantly more Aech. grebes than I have been seeing recently here. An individual tally turned up 223 Western Grebes, 79 Clark's, and 390 "slash." My most recent careful count here was Dec. 31st, where I counted 9 Western, 23 Clark's, and 124 "slash." I am unsure whether these large numbers of grebes have anything to do with the herring close by.
While I am here, yesterday I spent the day putzing around the delta. The visibility was absolutely horrendous until about 12:30-1 o'clock. Despite this, I counted a fair number of Lesser Yellowlegs spread between locations: 2 on Jersey, 8 on Bethel, and 4 on Sandmound Rd. Visibility was so horrendous on Holland and Palm Tracts when I checked them I had no idea if there was even shorebird habitat... but there has been some recently. Elsewise... on Taylor Rd. I found a Phainopepla, only my second for Bethel Island, and one nice Slate-colored Fox Sparrow among the sooties. Allen's Hummingbirds seem to not be in yet, per a fruitless check of Bethel Harbor. And Mute Swan numbers seem lower this winter... I only noticed a handful on Bethel Island yesterday, but I talked with Roger Muskat a couple days ago who was telling me about a flock of 600 he just counted. Oh, well.
