During Charles Darwin’s voyage aboard the Beagle, the eminent naturalist was clearly taken by a bird he described in Uruguay as “possessing a song far superior to that of any other bird in the country” (3). This bird was the chalk-browed mockingbird, a small, ubiquitous passerine, with a conspicuous white supercillium, or ‘eyebrow’, sandwiched between a blackish eye stripe and a dark grey crown (2) (4). The upperparts of its body are predominately greyish brown, while the flight feathers and the long semi-erect tail are blackish, with white tips. Below, the throat and belly are greyish white, but the flanks are often streaked with darker markings. Across the chalk-browed mockingbird’s broad range, four subspecies, which exhibit minor differences in body size, bill length and plumage, are currently recognised: Mimus saturninus saturninus, M. s. frater, M. s. arenaceus, and M. s. modulator (2).
- Length: 23.5 - 26 cm (2)