The shorebird roosts in the Cargill salt crystallizers and nearby salt pond (right across from Westpoint Harbor) have had amazing shorebird numbers on high tides over the past week or so. Yesterday I had comfortably over 10,000 Dunlin, ~3,500 dowitchers, and—most notably—an individual tally of 42 Lesser Yellowlegs. This is a truly exceptional count for San Mateo and perhaps the county high count, unless Ron, Peter, or others have a higher total in their old records.
Today in a quick stop at a slightly lower tide with Ethan Monk, Lucas and Mark Stephenson, and Chris Henry, there were again 31+ Lesser Yellowlegs (and likely more) as well as many thousands of other shorebirds.
Shorebird numbers here peak in late March and early April, when local winterers are augmented by northbound migrants (e.g., most of the Lesser Yellowlegs, which certainly did not winter locally in such high numbers) and good high-tide roost habitat, which is formed by the accumulation of rainwater on the salt ponds, is available. Tides over 4–5 feet are decent, with 6–7 feet usually being awesome. Afternoon is best for lighting. It looks like every day this week has good afternoon high tides.
This spot deserves more coverage and afternoons this week are a perfect opportunity for anyone interested in a somewhat respectable shot at finding a Ruff (or similar) in San Mateo! There is also a decent-sized gull roost out on the structures that divide the crystallizer ponds, and wintering Palm and Yellow warblers in the area. Viewing is best from around (37.50969, -122.20061) and from the trail paralleling Seaport Blvd along the westernmost Cargill crystallizer.
In other news, my FOS territorial Wilson's Warblers in the county were on 3/23 (feels a little late), Warbling Vireo and Blue-gray Gnatcatcher on 3/24 (a little early, especially considering that there were 3+ gnatcatchers at Jasper Ridge already), Hooded Oriole on 3/25, and Black-headed Grosbeak and Western Flycatcher (slightly late) on 3/29. Pretty much par for the course.
