Sunday, August 14, 2011

Greater Yellowlegs

After my last visit to Fernhill Wetlands, I realized that an evening visit would provide great light for the shore birds that frequent the mud flat on the Barney Reservoir Project. Remember that on most visits it's cloudy, especially this year.
I decided it was going to be a rental weekend, and I was able to reserve a 400mm f2.8 and a 1.7x teleconverter. I took it out to Fernhill Friday evening and my hunch was right, the sun was was providing perfect front light on the shorebirds.
At first there were mostly Western Sandpipers and a few Least Sandpipers. Then a few Spotted Sandpipers showed up. I took a lot of pictures and will post some in the next couple of days.
I finally got tired of kneeling on the ground (note to self: get knee pads) so I took a break and wandered the service roads a bit.
I decided to make one more pass by the mud flats before going home. When I arrived, the sun was low in the sky and had just crossed behind a small cloud, so the front light was lost. Just my luck, but now was when a Great Yellowlegs had decided to show up.
I crept down close and got what I had hoped would be great pictures, even with the low light. After all, I had a fast lens. Only trouble was, I forgot I had set my camera to aperture priority while the sun was bright to get a little more depth of field. All that speed was lost and most of the pictures of the Greater Yellowlegs were blurred.
Luckily, in the image above, the bird held still enough and I held the camera still enough that I got one pretty good shot.


  1. You know Rick -- from the head to bill size ratio, i'd say that was a Lesser Yellowlegs. How did you rule that out? Were there other birds around that you compared for size?

    just curious

  2. Hi Greg. Thanks for commenting. I did a rough measurement of the head to bill ratio at posting time and the bill was longer than the head. It is my understanding that whenever the bill is longer than the diameter of the head, it is a Greater.
    I just measured with a ruler on my computer screen and measured the bill at 2.3" and the head at 1.8". Wouldn't that indicate a Greater Yellowlegs?

  3. Well there is variation of course but 1.25 to 1.5:1 for Greater is what i've read. And in the picture only you know what plane the bird was on in relationship to the focal plane. If it is not exactly parallel then some foreshortening will take place.

    Your measurement puts the bird in the 1.25 range. I just eyeballed it. One other clue had me wondering and that is the primary projection. In the picture it looks like the primaries project past the tail -- a trait associated with Lesser.

    But you were there and have the best viewpoint on it. There's no way i can judge it's overall size by a photo without any reference. If you heard it vocalize that would be a clincher for sure.

    Greg Gillson did a post on this ID challenge a while back.

    Nice picture by the way.

  4. Hmmm, you're right about Greg's posting. Now I'm not so sure. I'll take closer look at the other pictures I took of it and see if they shed any further clues.

  5. As far as bill length this bird fits in the middle--it's not obvious either way. Though not giving the impression of being bent up on the lower mandible (as most Greaters), the bill is quite thick. The "knees" (actually the ankle joint) are obvious. Thus, I am not uncomfortable with Rick calling it a Greater Yellowlegs.

  6. Hi Greg. What is it about the knees that distinguishes it?

  7. Lesser has thinner legs and the ankle joint is less obvious than on Greater.

    Here they are together...