Tennessee Warbler vs. Orange-crowned Warbler
Early December in Oakville, Ontario is not typically a time of year when one expects to see either Tennessee Warbler or Orange-crowned Warbler. Yet on December 10, I had the good fortune to not only observe these two species; I was able to capture several uncluttered photos of each. It can be difficult to get unobstructed views of these birds past early spring; however, once the leaves fall chances of getting good views increase substantially. The location was the same as for the Northern Parula that I wrote about in a previous blog post.
Like many less experienced birders, I struggle to differentiate between the two species, unless of course one hears the song or call, which are very different. After downloading the images I made to my computer, I carefully reviewed my photos, referencing my guidebooks and consulting, when necessary, with much more experienced birders than I whenever I couldn’t make a definitive ID. My research turned up a few differentiating features that I believe have relevance to the group of photos below.
The images that follow may be helpful to those of you that wish to improve your ID skills with regards to these two species. I find it’s always nice to have examples of each type of species to make comparisons.
One of the keys to differentiation between the two species is the colour of the undertail coverts. They are whitish on most tennessee warblers (sometimes pale yellow but always whiter than breast) but always yellowish on orange-crowned warblers. The colour of the head blends in with the body on fall tennessee warblers. The head appears neckless on the Tennessee Warbler, which is not the case for Orange-crowned Warbler.
The whitish undertail coverts are quite evident on the tennessee warbler above. A little more subtler is that tennessee warblers are long winged but very short tailed. Compare this with the overhead view of the Orange-crowned Warbler (see image further below).
No blurry streaking on the breast in the Tennesse Warbler above; Orange-crowned Warbler show blurry or shadowy streaks.
Note the broken pale eye-arcs and the dark eye-line; subtle blurry streaking on the breast is also evident here.
A nice overhead view of Orange-crowned Warbler. Compare the length of its tail to that of the Tennessee Warbler; the tail is longer for Orange-crowned Warbler.
Shown above is a clear view of the undertail coverts. These undertail coverts are quite yellow. The tail here is light, but it can be dark gray.
I may not always correctly identify these two species going forward, but I do believe my odds of doing so have increased significantly. I hope you found this article helpful as well.