Sunday, July 15, 2018

Fall Warbler Identification: A tricky Orange-Crowned Warbler

I was browsing my local bird watching Newfoundland Facebook group and I came across a post referring to warbler that someone wanted some assistance to identify. I looked at the photo I immediately thought " this is an Orange-crowned Warbler. However, my immediate impression made no sense, because Orange-crowned Warblers do not breed in Newfoundland and there aren't any July records that I'm aware of. They are regular vagrants in late fall, but never in mid summer. This bird seemed to have all the attributes of an Orange-crowned Warbler, although it was kind of oddly gray, a characteristic I attributed to immaturity. Lets break down the id features of Orange-crowned Warbler and move along from there.

orange crowned Warbler under tail Labrador
Dull overall appearance, no wing bars, split eye ring, dark eye line, very sharply pointed bill, yellow under tail coverts and pale legs
Photo: Brian Bishop
Orange-crowned Warbler Labrador
Note the bill shape and contrasting yellow under tail coverts
Photo Brian Bishop

Orange-crowned Warbler

 -sharp pointed bill- also shared by close relative Tennessee Warbler (which does breed in Newfoundland regularly)
- dark eye line
- split eye ring
- generally grayish overall with some yellow wash. I'm used to seeing Orange-crowned appear greener above and more yellow below, often with faint smudgy streaking, but I'm kind of assuming this is a young bird, so I'm ok with the somewhat unusual colouration.
- lacking wing bars
- contrasting pale yellow under tail coverts 
- longish tail ( length of tail feathers, beyond the under tail coverts)

So even though this bird looked find for an Orange-crown I was trying to convince myself it wasn't. I thought about Tennessee Warbler. Tennessee shares the sharply pointed bill that this bird has, as well as the dark eye line, it lacks wing bars and maybe you could convince yourself the split eye ring was ok as well. However, there are severe issues with this being a Tennessee Warbler.

1) Under tail coverts- This bird clearly has yellow under tail coverts while Tennessee Warblers always have white under tail coverts in all plumages. As well this birds tail is much too long for a Tennessee Warbler, which has a little stump of a tail, poking out past the under tail coverts.

I considered Cape may Warbler. Admittedly, a bit of a stretch but immature Cape Mays can be extremely dull and, the bill shape in the second photo doesn't look terrible for Cape May. However, this bird lacks any streaking below, no sign of even a single wing bar and it has yellow under tail coverts.

What about the dullest Yellow Warbler ever? Some immature Yellow Warblers can be super dull, but the split eye ring and dark eye line don't work for yellow which often shows a complete, thin eye ring and the tail feathers themselves (not just the under tail coverts) always have some yellow in Yellow Warbler.

At this point I was really starting to run out of possibilities, so I went back and checked the location of the bird again- Labrador! What an idiot I was! Orange-crowned Warblers are locally common in parts of Labrador! Things started to make sense and all was right with the world again. If I had taken the time to read the location more carefully I could have saved myself 10 minutes, but I would have lost out on a really valuable learning exercise. Identifying this bird challenged me to consider everything I knew about Newfoundland's breeding warblers and gave me a nice little refresher in fall warbler ID.

When people post a photo to a group asking for an ID my first question is usually, well, What do you think it is? It's extremely useful to know what the person was thinking when attempting to identify a particular bird. If allows you to understand where they might have been lead astray, identify knowledge gaps and areas for improvement, or maybe they were right and a lack of self confidence is their enemy! If you struggle with Fall Warbler ID like many people, it doesn't have to be that way. You just need a plan, a structured approach to identifying these challenging birds. This is the exact type of approach we preach in out ID workshops and we happen to be offering a Fall Warbler ID workshop soon.

Not living in St.John's, no problem. Inquire about our online workshops!
I am thrilled to be able to provide educational and entertaining content. However, these articles are very time consuming to write. If possible please consider subscribing to the blog with a very small monthly fee via the subscribe button. This will help to cover costs of website maintenance and all the other expenses that go into producing the content. Whether you subscribe or not you will still have access to all the content, the small subscription fee is just a means of showing your support. Thank you!

Support Birding Newfoundland- subscription options
Fatbirder's Top 1000 Birding Websites

No comments:

Post a Comment

Popular Posts