Tagarela-pigmeu Pnoepyga pusilla

Essentially a tiny brown tennis ball supported by tiny chopsticks. Dark brown above with densely packed black-and-white scaling on the underside. Gives the impression of a tailless rodent as it makes its way furtively through dense shrubbery and leaf litter. Can be quite vocal and is jarringly loud for its size, giving single well-spaced piercing whistles on different high pitches, and occasionally an accelerating, usually rising rapid series of whistles. Also gives a sharp chip.