About Centronyx henslowii (Audubon, 1829)
This species is Henslow's sparrow, with the scientific name Centronyx henslowii (Audubon, 1829). Adult Henslow's sparrows have streaked brown upperparts, a light brown streaked breast, a white belly, and a white throat. They have a pale central stripe on the crown, with a dark stripe on each side of the stripe, an olive-colored face and neck, rust-colored wings, and a short dark forked tail. Measurements for the species are: length 4.3–5.1 inches (11–13 cm), weight 0.4–0.5 ounces (11–14 g), and wingspan 6.3–7.9 inches (16–20 cm). The overall range and population size of this bird is decreasing, most likely due to the loss of the grassland habitat that the species depends on. However, the species has benefited heavily from the Conservation Reserve Program created by the United States Department of Agriculture, which has helped to stabilize its population. As a result of this population stabilization, the species was downlisted to Least Concern from Near Threatened in 2018. The population of this bird in Texas was only known from a 105-acre (0.42 km2) brushfield near Houston; this population disappeared after devegetation caused by industrial development in the 1980s. This Texas population was originally described as a distinct subspecies, P. h. houstonensis (Arnold, 1983), but modern classification considers it to fall within the range of variation of the nominate subspecies, per a 1990 treatment by Browning. Similarly, the South Dakotan population formerly classified as P. h. occidentalis has been synonymized with the nominate subspecies. The only two subspecies that are generally (but not universally) accepted today are the eastern Henslow's sparrow and the western Henslow's sparrow; the Appalachian Mountains separate the ranges of these two subspecies for the most part.
