Mystery Sparrow Solved

Day 317: It's been a year for hard-to-identify birds at my house. I finally confirmed that the swarm of female hummingbirds were indeed Anna's after a female Rufous came to visit the feeder only a few minutes after a distinctly grey-bellied guest left it, allowing me to note the differences almost as easily as if they had been side-by-side. However, a bunch of ground-foraging sparrows settled in to cause a great deal of consternation as I pulled bird book after bird book down from the shelf in an effort to sort them out. The fact that they were feeding on the ground, behaving like Spotted Towhees with a cute little jump backwards to raise seeds from the grass, was the first clue that they weren't any of my regular sparrows. My first thought had been that they were young White-Crowned whose "racing stripes" hadn't fully brightened up, but their streaky undersides and behaviour took that out of consideration. The same reasoning ruled out Golden-Crowned, which appear here more infrequently. Song Sparrow was ruled out by the presence of faint white wing bars on many of them, as did the lack of a "tie-tack" on the breast. Their call was something I don't hear regularly as well. Standing at the window trying to get a clear view and/or photos as they scrabbled about in the weeds which pass as my lawn, I hadn't been able to observe the dark line through the eye. Once I saw it, all the puzzle pieces fell into place: ground forager, streaky underparts, faint wing bars, weak "moustache"...I had a flock of young Chipping Sparrows (Spizella passerina), another infrequent visitor to my yard. Now the "pip!" calls made sense, as did pinkish-yellow beaks beginning to turn black at the tips. LBJ or LGB (Little Brown Job or Little Grey Bird) identifications can be tricky, especially when the bird hasn't matured into its adult colouration.