Tuesday, August 25, 2009

Dowitcher, but Which One?

Yesterday I posted the photo above and labeled it as a Long-billed Dowitcher (Limnodromus scolopaceus). I also posted the photo to our Montana birding group site with the same ID. This morning I received a note from my friend Dan Casey concerning my ID. He thought it might be a Short-billed Dowitcher (Limnodromus griseus hendersoni), a subspecies most likely on the prairies and most similar to Long-billed Dowitchers. I have to confess that I hate trying to ID fall dowitchers and defaulted to Long-billed after a quick glance and my interpretation of the overall shape as being more rounded. I have paraphrased Dan's comments below:

Subtle but apparent "kink" to the outward third of the bill.
Distinctly spotted breast sides.
Slender build
Relatively few "breeding" wing coverts.
It is a bit sparsly marked on the flanks for a Short-billed Dowitcher but I think the other features outweigh that, and hendersoni should have the least here anyway.
What little we see of the tail is inconclusive, but may indicate that the white bars are equal in width to the black bars, tipping slightly towards Short-billed.

I also received comments on the bird from Caleb Putnam too. Caleb thought that this was a tricky individual to ID, but was leaning towards a Short-billed Dowitcher as well.

Both Dan and Caleb asked if I had more photos and I have added a number of them below (click on the photos to get a larger version). There were about 20 individuals on the reservoir that morning and I am not sure if any of the new photos show the individual Dan and Caleb commented on.
If you have any comments on the identification of these dowitchers I would appreciate hearing them.

A few of the group of dowitchers and a few other species.

Photo 1.

Photo 2 ( a bit blurry but may still helpful)

Photo 3.

Photo 4.

Photo 5 (same bird as photo 4).

Photo 6.

Photo 7 (same bird as in photo 6).

I will readily admit that I struggle with identifying these species and I am trying to get better so any help on the ID of these birds is appreciated.


Caleb Putnam said...

John- Don't feel bad- after spending hundreds of hours looking at 640+ specimens of both species for my master's degree, I still struggle with the trickier individuals in the hendersoni/Long-billed camp. Indeed, I threw several specimens out of the sample b/c I just couldn't be sure which species they were- birds that looked just like this one.

But tell me something- the mystery bird in photo 1- is it visible in any of the other photos, and if so, which bird is it?

Dan Casey said...

John: Glad to have started this discussion, and certainly I would admit also that separating fall adults of these two is the greatest challenge. In looking over the additional photos, only one bird strikes me as a really good candidate for SBDO, and it is the juvenile on the left in the first group photo. Wish we could see the tertials better. The birds in flight are certainly Long-billed, based on the white lesser coverts. And the feeding birds look hunchbacked (LBDO) as well. I will look forward to what others have to say. Certainly if the bird in the original photo is in one or more of these, it does not stand out!

Nate Kohler said...


In the top photo of the group, I would say that the left bird in the foreground is a juvenile SBDO. all of the others appear to be LBDO with the exception of the Wilson's Phalarope, Semipalmated Sandpiper and Stilt Sandpiper. I didn't see any thing in any of the other photos that looked SBDOish.

Nate Kohler

John Carlson said...

OK Nate, I am going to have to put on my high school teacher hat and ask you to explain your answer!