Wednesday, February 5, 2014

Another Ferry Point Herring Run, Another Slaty-backed Gull

This afternoon I was fortunate (hella fortunate) to find what appears to be another Slaty-backed Gull at Ferry Point in Richmond, which then moved over to the big pond at Miller-Knox Regional Shoreline. Amazingly (awesomely) this is not the same Slaty-backed I had seen at Miller-Knox the previous day, and I was lucky to have a lot of highly-skilled larophiles present to help give the bird a going-over.

In bright sunlight, the bird seemed unusually pale-backed for a Slaty-backed (it looked more typical in overcast light), which I won't pretend to be able to explain was odd but seemingly within the range of variability for the species (see links below). Everything else looked very nice though...present (but difficult to see here) are its brightly-colored legs and blood-red orbital ring.

For more on variability of mantle color in Slaty-backed Gull, check out this comprehensive post and the Ujiharas' extensive gallery of Japanese Slaty-backs right here.

This individual has many more markings on the head and neck than the other Slaty-backed that has been appearing at bay area herring runs.

Nice wide, white trailing edge of the wing. It's molting some of its inner secondaries. See the top and bottom photos of this post for the best views of the primary pattern.

Of course, a nice string of pearls as well. Cool bird! If you have experience with SBGU and agree or disagree with the ID, we would love to hear from you.


  1. Nice find.

    I don't really know what most of the words mean that you used, but nice nonetheless.
    Back pats and con-grats for the Slaty-back

    1. Thanks. It will be interesting to see what the bird police say, but at least a couple officers saw the bird today.

    2. For my own edification, is the bold orbital ring the key identifying feature on this bird, more so than variable hues of 'slaty'?

    3. The orbital ring color is very, very helpful because only one other pink-legged west coast gull (Vega, which is probably just as rare) has a red orbital. The darkness of the back is variable, although its always pretty dark compared things like American Herring Gulls. But the magic words most often used to ID adult Slaty is "string of pearls".

    4. "only one other pink-legged west coast gull (Vega, which is probably just as rare) has a red orbital"

      Doesn't a Thayer's Gull have that same characteristic? Not that that would be confused with a Slaty-backed.

  2. Mighty fine, Tucker. Mighty fine.