Timing is everything. I missed a photo of a brightly-colored towhee earlier but while walking back into my kitchen I spied a Pine Warbler on the suet feeder.
The first time I saw this activity was a couple years ago and I had to do a double-take because at first glance I thought it was a female goldfinch. I was glad I'd taken a second look since that was my first viewing of a Pine Warbler in the wild.
Now, every spring, I await the return of the Pine Warblers and Yellow-rumped Warblers since both flock to the suet feeder, making for excellent viewing.
Last week Professor Dan posted information on his blog about how the design of the Yellow-rumped Warbler's digestive system allows it to have a wider diet than other warblers; helping it survive the harsher weather conditions it faces as one of the earliest migrating warblers.
I'm guessing that the Pine Warbler's digestive system is similar to the Yellow-rumped since it is the only wood warbler whose diet consists heavily of seeds. Because of this, they're frequently seen in backyards (especially those with pines). In fact, it turned its beak up at the mealworms located just a foot away from the suet feeder today. Of course, during the summer they do consume primarily insects, but they're often found hammering away on seeds wedged into the bark of a pine tree much like a woodpecker or a nuthatch.
I always think if more people really looked closely at their backyard birds they'll see species they've not noticed before, and this is one of the prime examples - it just kind of blends in with your other birds.