On October 4th I reported seeing an "adult" Long-billed Dowitcher in basic plumage, during the afternoon of 10/3/15, at Whitney Creek in Addison. The next day (the 4th) and the day after that (the 5th) several birders saw what may have been the same bird as the one that I had seen on the 3rd and thought that it may have been a Short-billed Dowitcher, but without certainty. Then on the 5th, one of them heard it for the first time and confirmed that it was indeed a Long-billed Dowitcher. I also found out that one of them had sent photos of the bird to an expert (great idea) and that person ID'd it as a "juvenile" Long-billed Dowitcher. After that I started asking myself, "Why did I think that I was looking at an adult?" . . . I wrote in my post that I could see no buffy or rusty colored edges or fringes on any of the upper scapulars (I meant to just write scapulars) or tertials, which ruled out juvenile. I have since done a decent amount of research and have found that I was not using enough information to make that determination. I then thought, maybe I could compare photos of the bird sent to the expert and see if that bird and my bird were in fact, the same bird. Then I came to the realization that it didn't matter if they were/are the same bird. I had already ID'd it as an "adult", which it may or may not have been.
Once I finished my research, I came to the conclusion that at this point in time, I cannot tell the difference between a basic plumage adult Long-billed Dowitcher and a basic plumage adult Short-billed Dowitcher. The differences are so subtle that even the experts can have trouble with that ID. Therefore, because I admit that I cannot tell them apart, my ID of an adult Long-billed Dowitcher on 10/3/15 is not a valid one.
Furthermore, I had also written (in that same report) that I had to watch that bird for 1 hr. and 41 minutes before it finally flew, so that I could get a good look at the tail to see if it was mostly black or not. I saw that it looked mostly black and I also wrote that I did get a good look at the tail bars when it touched down closer to me and did see that the black bars were wider than the white bars. I even wrote that it was a reliable way to tell Dowitchers apart. Well, that is just not true. According to what I read: If the tail shows wider white bars than black bars, it can never be a Long-billed Dowitcher (very helpful info). If the tail shows even width black and white bars, it could be either Dowitcher (good to know). If the tail shows wider black bars than white bars, it is likely a Long-billed Dowitcher but that on occasion Short-billed Dowitchers can have that same type of barring (not great info). Once again, my statement about the tail bars is not a valid one. The problem with telling the Dowitchers apart is that much of the information about field marks seem to overlap to either species. An observer really has to spend a lot of time watching a/or Dowitcher(s) and record all of the noticeable field marks (including the tail bars) and then one can collectively take a shot at getting a positive ID. Good luck- you are going to need it.
I have already changed my report on 10/3/15 from 1 Long-billed Dowitcher to 1 Short-billed/Long-billed Dowitcher.
The bottom line is, if you hear a Dowitcher and can also tell which one you are listening to, then you can give that particular Dowitcher an accurate ID. You can also get a positive ID if you see a "juvenile" Dowitcher that has not yet started transitioning into its' 1st winter plumage. Alternate plumage Dowitchers in the Spring can also be ID'd fairly well unless an adult "Prairie" Short-billed Dowitcher drops in somewhere around here.
I know that I have only scratched the surface on the difficulties of telling Dowitchers apart and if you would like to do your own research, go to the home page of Vermont eBird and scroll to the bottom of that page. Click on the word, "older" then scroll down and click on the article entitled, "Due Diligence with Vermont Dowitchers" (31 August 2014). That article is very helpful but then also click on the blue colored and underlined "Another website" link and/or the blue colored and underlined "here" link. The "Another website" link has a good bit of info and will also show another link to surfbirds.com if you would like even more reading. The "here" link will bring you to Cin-Ty Lee's webpage and you will need to click on the icon- Studies in Nature, then scroll down and click on Dowitcher Identification for even more reading.
I'm sure that there are birders who don't have difficulty telling Dowitchers apart but for those like myself, we'll just have to keep trying. . .
I hope that at least some of you find this helpful rather than confusing.
Enjoy Birds as well as the difficulties involved in IDind them,