Rufous-crowned Sparrow
Aimophila ruficeps
Summary 4
The rufous-crowned sparrow (Aimophila ruficeps) is a small American sparrow. This passerine is primarily found across the Southwestern United States and much of the interior of Mexico, south to the transverse mountain range, and to the Pacific coast to the southwest of the transverse range. Its distribution is patchy, with populations often being isolated from each other. Twelve subspecies are generally recognized, though up to eighteen have been suggested. This bird has a brown back with darker streaks and gray underparts. The crown is rufous, and the face and supercilium are gray with a brown or rufous streak extending from each eye and a thick black malar streak.
Description 5
The rufous-crowned sparrow is a smallish sparrow at 5.25 inches (13.3 cm) in length, with males tending to be larger than females. It ranges from 15 to 23 g (0.53 to 0.81 oz) in weight and averages about 19 g (0.67 oz). It has a brown back with darker streaks and gray underparts. Its wings are short, rounded, and brown and lack wingbars, or a line of feathers of a contrasting color in the middle of the bird's wing. The sparrow's tail is long, brown, and rounded. The face and supercilium (the area above the eye) are gray with a brown or rufous streak extending from each eye and a thick black streak on each cheek. The crown ranges from rufous to chestnut, a feature which gives it its common name, and some subspecies have a gray streak running through the center of the crown. The bill is yellow and cone-shaped. The sparrow's throat is white with a dark stripe. Its legs and feet are pink-gray. Both sexes are similar in appearance, but the juvenile rufous-crowned sparrow has a brown crown and numerous streaks on its breast and flanks during the spring and autumn.
The song is a short, fast, bubbling series of chip notes that can accelerate near the end, and the calls include a nasal chur and a thin tsi. When threatened or separated from its mate, the sparrow makes a dear-dear-dear call.
Distribution and habitat 5
This bird is found in the southwestern United States and Mexico from sea level up to 9,800 feet (3,000 m), though it tends to be found between 3,000 and 6,000 feet (910 and 1,830 m). It lives in California, southern Arizona, southern New Mexico, Texas, and central Oklahoma south along Baja California and in western Mexico to southern Puebla and Oaxaca. In the midwestern United States, the sparrow is found as far east as a small part of western Arkansas, and also in a small region of northeastern Kansas, its most northeastern habitat. The range of this species is discontinuous and is made up of many small, isolated populations. The rufous-crowned sparrow is a non-migratory species, though the mountain subspecies are known to descend to lower elevations during severe winters. Male sparrows maintain and defend their territories throughout the year.
This sparrow is found in open oak woodlands and dry uplands with grassy vegetation and bushes. It is often found near rocky outcroppings. The species is also known from coastal scrublands and chaparral areas. The rufous-crowned sparrow thrives in open areas cleared by burning.
Conservation 5
The rufous-crowned sparrow is treated as a species of least concern, or not threatened with extinction, by BirdLife International due to its large geographical range of about 463,323 sq mi (1,200,000 km2), estimated population of 2.4 million individuals, and lack of a 30% population decline over the last ten years. In years without sufficient rains, many birds fail to breed and those that do produce fewer offspring. Some of the local populations of this bird are threatened and declining in number. The island subspecies and populations have declined in some cases: A. r. sanctorum of the Todos Santos Islands is believed to be extinct, and the populations on Santa Catalina Island and Baja California's Islas de San Martin have not been observed since the early 1900s. Populations of the species in southern California are also becoming more restricted in range because of urbanization and agricultural development in the region. Additionally, the sparrow is known to have been poisoned by the rodenticide warfarin, though more research is needed to determine the effects of pesticides on the rufous-crowned sparrow.
Sources and Credits
- (c) Pablo Lèautaud, some rights reserved (CC BY-NC-ND), uploaded by Pablo Lèautaud, http://www.flickr.com/photos/98478281@N00/525698362
- (c) Mickey Long, some rights reserved (CC BY-NC), uploaded by Mickey Long
- (c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Aimophila_ruficeps
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Rufous-crowned_sparrow
