About Zonotrichia albicollis (J.F.Gmelin, 1789)
The white-throated sparrow, with the scientific name Zonotrichia albicollis (J.F.Gmelin, 1789), is a passerine bird that belongs to the New World sparrow family Passerellidae. It measures between 15 and 19 cm (5.9 to 7.5 in) in length, and has a wingspan of 23 cm (9.1 in). Its typical weight ranges from 22 to 32 g (0.78 to 1.13 oz), with an average weight of 26 g (0.92 oz). Its standard measurements are as follows: wing chord 6.3 to 7.9 cm (2.5 to 3.1 in), tail 6.8 to 7.7 cm (2.7 to 3.0 in), bill 1 to 1.2 cm (0.39 to 0.47 in), and tarsus 2.2 to 2.4 cm (0.87 to 0.94 in). It is similar in appearance to the white-crowned sparrow, but can be distinguished by its white throat markings and yellow lores. There are two distinct plumage variations for adult individuals: tan-striped and white-striped forms. In the white-striped form, the crown is black with a white central stripe, the supercilium is white, and the auriculars are gray with the upper edge forming a black eye line. In the tan form, the crown is dark brown with a tan central stripe, the supercilium is tan, and the auriculars are gray or light brown with the upper edge forming a brown eye line. Both variations share the following features: dark eyes, a white throat, yellow lores, and a gray bill. Some individual birds show variation, and may have dark lateral stripes on each side of the throat. White-throated sparrows almost always breed with individuals of the opposite color morph. The two color morphs occur in approximately equal numbers in the population. Both male and female white-striped birds are more aggressive than tan-striped birds during the breeding season. This increased aggression is linked to a higher rate of estrogen receptor alpha expression in white-striped birds. The breast has gray or tan streaks that continue down the flanks, while the belly is generally light gray. The wings are rufous, with two distinct white wing bars. Males and females are morphologically similar.
