The Small Brown Bird at My Feeder

Almost every one is one of four birds, and one look at the breast separates them.

Look at the breast

Plain and unstreaked, warm buff-brown — female house sparrow. There is a pale stripe behind the eye and a faint buff wing bar, and the face has no strong pattern. She is the commonest answer in any town or suburb.

Blurry, indistinct streaking on a greyish chest — female house finch. The streaks are soft and run down the flanks. The face is plain with no clear eyebrow. The bill has a distinctly curved upper edge.

Heavy, coarse streaking converging into a dark spot in the middle of the chest — song sparrow. The face is patterned in brown and grey with a broad grey eyebrow. This is the classic native sparrow and the spot is the fastest check in the whole group.

Uniform grey-brown with no pattern at all — female brown-headed cowbird. Plain everywhere, faintly streaked below, with a short thick conical bill and a pale throat.

The comparison

What is not a small brown bird

Two things get filed here wrongly.

Female cardinal — buff-brown, and people do not connect her with the red male. She has a crest and a heavy orange bill, and both are unmistakable once you look. She is far larger than any of the four above.

Female red-winged blackbird — heavily streaked and sparrow-like in pattern, but much bigger, with a long sharp pointed bill rather than a conical one. Usually near water.

The trap in all of this

Colour is doing no work here, and that is the point. All four birds are brown. What separates them is pattern and bill shape, which is the argument in starting with the bill rather than the colour.

If you cannot see the breast clearly, look at the bill instead: a house finch's curves along the top, a cowbird's is short and thick and finch-like on a body far too big for a finch, and a song sparrow's is small and neat.

Winter changes the list

From roughly October, dark-eyed juncos arrive across most of the continent and feed on the ground under feeders. They are slate-grey above rather than brown, with a clean white belly, a small pink bill, and white outer tail feathers that flash every time they fly. Once you know the tail flash they are impossible to mistake.

American goldfinches also moult into a drab olive-buff and get reported as small brown birds all winter. The black wings with white bars stay the same year-round and are the giveaway.

If you want fewer house sparrows

They are introduced, aggressive, and they evict native cavity nesters. Nothing excludes them entirely, but the seed choice helps:

• Safflower — cardinals, chickadees and finches take it; house sparrows and starlings largely do not.
• Nyjer in a mesh feeder — goldfinches and siskins only.
• Avoid mixed seed with a lot of millet and cracked corn, which is what draws them in numbers.

Removing the ground spill matters as much as the feeder, since that is where they mostly feed.