Autumn LBJs: Dealing with Juveniles


Birding is harder in the fall. A lot of birds look very different in the autumn; Blackpoll Warblers, for example, look like completely different species.

Blackpoll Warbler, Spring/Summer Plumage

Blackpoll Warbler, Spring/Summer Plumage

Blackpoll Warbler, Autumn/Winter Plumage (Photo by Matthew Brady)

Blackpoll Warbler, Autumn/Winter Plumage (Photo by Matthew Brady)

Yes, that really is the same bird species.

But the juveniles are even worse. Hatch years birds may not look anything like their parents. And among hatch year birds, sparrows can be pretty difficult. Birders call them LBJs – Little Brown Jobs – as they try to find field marks to sort them out.

Probable Juvenile Vesper Sparrow, New Meadows, Idaho

Probable Juvenile Vesper Sparrow, New Meadows, Idaho

WC thinks this is likely a hatch year Vesper Sparrow. There’s a complete white eye ring, the belly is creamy white and you can just make out some rufous in the lesser coverts. But WC could be completely wrong.

Probable Juvenile Savannah Sparrow, New Meadows, Idaho

Probable Juvenile Savannah Sparrow, New Meadows, Idaho

WC thinks this is likely a hatch year Savannah Sparrow. The yellow lores – the front half of the eyebrow – and the heavier streaking an smaller bill seem to suggest a Savannah. But, again, WC could be completely wrong.

Probable Juvenile White-crowned Sparrow, Sawtooth NRA, Idaho

Probable Juvenile White-crowned Sparrow, Sawtooth NRA, Idaho

This one is a little easier, because there aren’t that many sparrows with a medial stripe down the crown of their head. WC thinks this is a juvenile White-crowned Sparrow. Probably.

Maybe a juvenile Song Sparrow, Payette Lake, Idaho

Maybe a juvenile Song Sparrow, Payette Lake, Idaho

WC is reduced to a guess on this one, possibly a Song Sparrow, a highly variable species, whose juveniles are even more variable. The habitat was right, and the heavy bill is right. The yellow-green cast on the underside is likely reflected light from the moss clump. Or WC could be completely wrong.

LBJs are hard. It’s one of the things that makes birding a challenge. Feel free to make your ID corrections in comments.

Advertisements