This is the familiar “little brown bird” usually seen spiralling upward around trunks of big trees, then planing down to the base of the next tree, only to repeat the process. They build their fragile nests behind loose flakes of bark. During migration they are often seen in the big trees lining city streets , but they usually retire to the forests to breed.
They are smaller than House Sparrows, brown on the back and white below, with slender, down-curved beaks and stiff woodpecker-like tails used to prop them up as they creep up the rough bark of trees. The usual note heard is a high-pitched “pseeee”, somewhat like the note of the Golden-crowned Kinglet but in this case a single long-drawn note, not repeated as in the kinglet. The high-pitched song reminds me (in rhythm) of the nursery jingle “fee-fie-fiddly-fum”: Saunders (in 1947) wrote the song as “Pee-e-see, pe-see, see see” (rising, falling, high, low).