Sunday, March 20, 2016

Herring Run! Slaty-backed, Thayer's, Hybrids and More


Immediately after returning from Mexico, I quickly found out that I did not have the typical birding hangover I usually endure after such prolonged, lifer-filled birding. A herring run was raging at Point Richmond, where it does every winter, so following a report of THE Slaty-backed Gull, Don Francisco headed out into the rain to wage mental war with thousands of feeding gulls...ersatz birding this was not. One of the first birds of note that we picked out was this first cycle Glaucous X Glaucous-winged Gull, an uncommon hybrid combo in the bay area.


This bird was quite typical looking; first cycle GLGU X GWGU hybrids in my experience show surprisingly little variation. They are big and bulky birds, generally shaped like GWGU, but with obvious pink on the bill (blending into the black tip) and plumage that recalls a dingy GLGU.


Thayer's Gulls have not appeared in many BB&B posts so far this year. This changes everything. This is a pale-eyed individual, not unusual to find around these parts. Note the very large white apical spots, one of the things that helps differentiates this from a wee Herring Gull.


For your edification, here is a first cycle Thayer's with a lot of white on the back.


This is a darker first cycle Thayer's, still quite "fresh" looking; many Thayer's look considerably paler and worn by this time (late January).


And here is a second-cycle Thayer's showing a classic wing pattern.


Don Francisco had never experienced such an intense gull scene. He was in awe.


As everyone knows, Don Francisco has excellent luck, so I figured it was just a matter of time before the Slaty-backed Gull made an appearance. Sure enough, we were lucky to see the bird for a few minutes after waiting around for a couple hours. This bird has been coming to bay area herring runs for many years, and I was happy to get reacquainted.


The white wing covert and "clean" head makes this bird easy to identify as the same returning individual. Whenever I'm birding a herring run, I'm always looking for this particular bird (among others, obvi).


With such a bounty of food available, much more than just gulls show up to partake in the feast. Pelagic Cormorants always attend in small numbers.


Big flocks of diving ducks feast as well.


Herring runs provide some of the best gulling in the western U.S., and is a major perk to winter birding in the bay area. Hopefully a Black-tailed Gull will show up one of these days!

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