10 October 2023

Migrating chipping sparrows (Spizella passerina) have just begun to arrive in Pittsburgh and they look different than they did last spring. The adults are fading and the juveniles, which never did match the adults, now resemble other species. We have a category for Confusing Fall Warblers. There ought to be one for Confusing Fall Sparrows.

From mid-March to mid-April chipping sparrows molt rapidly into breeding plumage with a rusty cap, a sharp white swatch above the black eyeline and rusty-orange tones on the wings.

In mid-August the adults being two and a half months of molting into duller non-breeding plumage, looking ragged in September and ending up with the brownish cap and muted facial markings of non-breeding plumage.

Meanwhile the juveniles lose the spotted breast they fledged with and gain sharper facial markings. Sometimes they look like clay-colored sparrows which are indeed rare in Pittsburgh.

Let’s compare the young chipping sparrow at Frick Park to an October clay-colored sparrow: chipping on the left, clay-colored on the right below. These small photos are just like the long distance view in the field.

They look almost the same. What’s the difference?

• The chipping sparrow has a strong black eyeline that extends all the way to its beak and its face patch has muted edges.
• The clay-colored sparrow has no black between its eye and beak but it does have a dark “moustache” outlining the front edge of its face patch.
• If you can see the top of the head, the young chipping sparrow may have thin white stripes but the clay-colored has a distinctly wide white crown-stripe.

And just to shake things up, there was a leucistic adult chipping sparrow at Frick last Saturday who looked as if he had been dunked face-first in white paint. His forehead, cheeks and throat were so white that it the camera had a hard time picking up the details.

Theorectically leucism (lack of pigment) is in his genes so his face will always looks like this no matter what plumage he’s in. He’s the only chipping sparrow I can identify as an individual.

p.s. More confusion: When American tree sparrows arrive later this fall they’ll resemble chipping sparrows in breeding plumage, except that the chipping sparrows will be in non-breeding plumage. Click here and scroll down to see American tree sparrows compared to chipping sparrows at All About Birds.

(photos from Charity Kheshgi, Lauri Shaffer, Steve Gosser and Wikimedia Commons)