One migrant that I’m sure to see every spring are Swainson’s Thrush, usually in pretty good numbers. They typically start to show up in late April, with about a 3-4 week period where you might run into them. It’s pretty predictable where they can be found. They are usually seen foraging in the grass on the edge of the forest or some other wooded area. They’re always a little “on edge”, sticking close to that forest cover so they can dash into it at any sign of danger. Because of their behavior, they can be hard to photograph sometimes, but on the other hand, I’ve had a lot of chances over the years because they’re pretty common.
There are a few other thrush species they could potentially be confused with. Hermit Thrush is the first of the thrush species to migrate in the spring, but there still can be a few around by the time Swainson’s Thrush arrive. However, I’ve never had too much trouble differentiating Hermit Thrush from Swainson’s Thrush, as they have a rich, reddish-brown rump that easily makes it stand out (if seen well). Veery are another thrush species that migrates through the state (with some breeding in the Black Hills). They’re pretty uncommon, but even if they are seen here, their color is a much richer, warm, reddish brown, and they have less spotting on the undersides than a Swainson’s Thrush. I’ve never had difficulty identifying them either.
But there is one thrush species that can be difficult to differentiate from Swainson’s Thrush…the Gray-cheeked Thrush. One of the difficulties in differentiating the two species lies in their habits! Both have that tendency to hang out at the forest edge, in the shadow of the trees. Because they’re often seen in poor lighting conditions, it’s often difficult in field conditions to differentiate the two.
Gray-cheeked Thrush have also been something of a nemesis bird for me, from a photographic standpoint! I would estimate that at least 90% of the Swainson’s/Gray-cheeked Thrushes I’ve seen over the years have been Swainson’s (if not a higher percentage). Despite that, I HAVE seen and identified Gray-cheeked over the years, but until today I really didn’t have any good photos (or even any recognizable photos!). That problem was taken care of today at Newton Hills State Park, when I got photos of BOTH species in relatively good lighting.
The image below depicts Gray-cheeked and Swainson’s Thrushes. Sure, it’s easy when they’re side by side, in good light! This is the exception rather than the rule, however. If you do have the opportunity to see them in good light, Gray-cheeked Thrushes are 1) Grayer in overall plumage, with few buffy or warm tones, 2) lack of any ring around the eye, and 3) a gray cheek (surprise!) with no warm tones on the face. Swainson’s Thrushes often appear “buffier” and more rich in color overall (although still nowhere close to as rich as a Veery), and have characteristic buffy tones on the face. They also have an obvious eye ring.
It’s all about getting a good look! If you’re having trouble identifying these species, and you can’t see the bird’s eye ring (or lack thereof), or if the lighting is poor and you can’t judge how “buffy” the face is…good luck! You’re on your own! But if you do get a chance to see one of these two species in good light, I hope the photos below and identification points above are of some help.