Rufous-crowned Sparrow

Taxobox
name = Rufous-crowned Sparrow

---

status = LC
status_ref=IUCN2006|assessors=BirdLife International|year=2004|id=53584|title=Aimophila ruficeps|downloaded=12 May 2006]
status_system = iucn3.1
regnum = Animalia
phylum = Chordata
classis = Aves
ordo = Passeriformes
familia = Emberizidae
genus = "Aimophila"
species = "A. ruficeps"
binomial = "Aimophila ruficeps"
binomial_authority = (Cassin, 1852)The Rufous-crowned Sparrow, "Aimophila ruficeps", is a medium-sized 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. In the midwestern USA, the sparrow is found throughout central Oklahoma, and as far east as a small part of western Arkansas; its also found in a small region of northeastern Kansas, its most northeastern range.

Taxonomy

The Rufous-crowned Sparrow was described in 1852 by John Cassin as "Ammodramus ruficeps". The derivation of the current genus name, "Aimophila", is from "aimos"/αιμος 'thicket' and "phila"/φιλα 'loving'. [cite book |title=Dictionary of Birds of the United States: Scientific and Common Names |author=Holloway JE|year=2003 |publisher=Timber Press |location=Portland, Oregon |isbn=0881926000 |pages=p. 17] Its specific epithet is a literal derivation of its common name, derived from the Latin words "rufus" 'rufous' and "-ceps", from "caput" 'head'. [cite book | last = Simpson | first = D.P. | title = Cassell's Latin Dictionary | publisher = Cassell Ltd. | date = 1979 | edition = 5 | location = London | pages = 883 | id = ISBN 0-304-52257-0] The bird is also occasionally referred to colloquially as the Rock Sparrow because of its preference to live on rocky slopes.

ubspecies

Twelve subspecies are generally recognized, though sometimes up to 18 are named.

*"A. r. ruficeps", the nominate subspecies, was described by John Cassin in 1852. It is found in the coastal ranges of California and on the western slopes of the Sierra Nevada.cite book| last = Clements| first = James F| authorlink = James F. Clements | title = The Clements Checklist of Birds of the World Sixth Edition| publisher = Comstock Publishing Associates| date = 2007| location = Ithaca, NY| pages = 681-682| isbn = 978-0-8014-4501-9]

*"A. r. canescens" was described by W.E. Clyde Todd in 1922. It is found in southwestern California and northeast Baja California as far east as the base of the San Pedro Martir. While the species itself is listed as of Least Concern, this subspecies is listed as a species of special concern by the California Department of Fish and Game.

*"A. r. obscura" was described by Donald R. Dickey and Adriaan Van Rossem in 1923. It is found on the Channel Islands of Santa Cruz, Anacapa, and formerly Santa Catalina.cite web| last = Thorngate| first = Nellie | coauthors = Monika Parsons | title = California Partners in Flight Coastal Scrub and Chaparral Bird Conservation Plan Rufous-crowned Sparrow (Aimophila ruficeps) | publisher = California Partners in Flight | date = 2005 | url = http://www.prbo.org/calpif/htmldocs/species/scrub/rufous_crowned_sparrow.htm| accessdate =2008-01-19 ] While the Santa Catalina population has not been observed since 1863, the subspecies seems to have recently colonized Anacapa Island.

*"A. r. sanctorum" was described by Adriaan Van Rossem in 1947. It is found on the Todos Santos Islands off the coast of northwest Baja California. However, this subspecies has not been seen since the 1970s.

*"A. r. sororia" was described by Robert Ridgway in 1898. It is found in the mountains of southern Baja California, specifically the Sierra de la Laguna.

*"A. r. scottii" was described by George Sennett in 1888. It is found from northern Arizona to New Mexico south to northeastern Sonora and northwestern Coahuila.

*"A. r. rupicola" was described by Adriaan Van Rossem in 1946. It is found in the mountains of southwestern Arizona.

*"A. r. simulans" was described by Adriaan Van Rossem in 1934. It is found in northwestern Mexico from sotheastern Sonora and southwestern Chihuahua to Nayarit and northern Jalisco.

*"A. r. eremoeca" was described by N. C. Brown in 1882. It is found from southeastern Colorado to New Mexico, Texas, northern Chihuahua, and central Coahuila.

*"A. r. fusca" was described by Edward William Nelson in 1897. It is found in western Mexico from southern Nayarit to southwestern Jalisco, northern Colima, and Michoacan.

*"A. r. boucardi", described by Philip Sclater in 1867, is found in eastern Mexico from southern Coahuila to San Luis Potosi, northern Puebla, and southern Oaxaca.

*"A. r. australis" was described by Edward William Nelson in 1897, and occurs in southern Mexico from Guerrero to southern Puebla and Oaxaca.

Description

The Rufous-crowned Sparrow is a medium-sized sparrow at convert|5.25|in|cm|.01|... in length.cite web| last = Gough| first = Gregory| title = Rufous-crowned sparrow Aimophila ruficeps| work = Patuxent Bird Identification InfoCenter| publisher =USGS Patuxent Wildlife Research Center | date = 2000-12-28| url = http://www.mbr-pwrc.usgs.gov/Infocenter/i5800id.html| accessdate =2007-01-18 ] It has brown back with darker streaks and gray underparts. Its wings are brown and do not have wingbars. The sparrow's tail is long, brown, and rounded. The face and supercilium are gray with a brown or rufous steak extending from each eye and a thick black malar streak. This sparrow also has rusty crown which gives it its common name. The bill is yellow and conical shaped. 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 from spring to fall. The song is a short, fast, bubbling series of "chip" notes, and the calls include a nasal "chur" and a thin "tsi".cite book | last = Byers | first = Clive | coauthors= Curson, Jon; Olsson, Urban |title = Sparrows and Buntings: A Guide to the Sparrows and Buntings of North America and the World | year = 1995 | publisher = Pica Press| isbn =1873403194| pages = 296–7 ]

Distribution and habitat

This bird is found in the southwestern United States and Mexico from sea level up to 9,800 ft (3000 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. The range of this species is discontinuous and is made up of many small, isolated populations in different locations. 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.

The 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 shrublands and chaparral areas. The Rufous-crowned Sparrow thrives in the open areas that result from an area being burned.

Ecology and behavior

The average territory size of Rufous-crowned Sparrows in the chaparral of California is convert|0.89|ha|acre|.01|... to convert|1.5|ha|acre|.01|.... The density of Rufous-crowned Sparrow territories ranges by habitat, including 2.5 to 5.8 territories per convert|40|ha|acre|.01|... of three to five year old burned chaparral to 3.9 to 6.9 territories for the same amount of coastal scrubland.

The Rufous-crowned Sparrow forages in pairs during the breeding season and in family-sized flocks in late summer and early fall. During the winter they can occasionally be found in loose mixed-species flocks.

Diet

This sparrow feeds primarily on small grass and forb seeds, fresh grass stems, and tender plant shoots during the fall and winter. During these seasons, insects such as ants, grasshoppers, ground beetles, and scale insects make up a small part of its diet. In the spring and summer, the bird's diet includes both more insects and a more diverse array of species of insects.

The Rufous-crowned Sparrow forages on or near the ground by walking or hopping under shrubs or dense grasses. Though it occasionally forages in weedy areas, it is almost never observed foraging in the open. It has occasionally been observed feeding in branches and low shrubs. During the breeding season, it gleans its food from grasses and low shrubs. Normally the species obtains its food by either pecking or less frequently scratching at leaf litter.

It is unknown whether this species obtains all of its water from the food its eats or if it must drink; however, it has been observed both drinking and bathing in pools of water after rain storms.

Reproduction

The Rufous-crowned Sparrow breeds in successional scrubland. While it is not known when precisely the breeding season starts, the earliest that a sparrow has been observed carrying nesting material was on March 2 in southern California. It builds a bulky, thick-walled open-cup nest typically on the ground, though occasionally in a low bush up to 45 centimeters above it, from dried grasses and rootlets, sometimes with strips of bark, small twigs, and weed stems. Nests are well hidden, as they are built near bushes or tall grasses or overhanging rock with concealing vegetation. Once a sparrow chooses a nesting site, it tends to return to the site for many years. It lays between two and five eggs at a time and may raise two broods a year. Juveniles tend to leave their parent's territory and move into adjacent habitat in the fall or early winter.

Conservation

The Rufous-crowned Sparrow is treated as a species of Least Concern by BirdLife International due to its large geographical range of about 320,000 mi² (1,200,000 km²), estimated population of 2.4 million individuals, and lack of a 30% decline overall in the species's population over the last ten years.cite web | title = Species factsheet: Aimophila ruficeps| publisher = BirdLife International | date = 2007 | url = http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=9023&m=0| accessdate =2008-01-19 ] However, 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" has not been seen on the Todos Santos Islands since the 1970s and the populations on Santa Catalina Island and Baja California's Islas de San Martin 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.

References

Further reading

Book

* Collins, P. W. 1999. "Rufous-crowned Sparrow (Aimophila ruficeps)". In T"he Birds of North America", No. 472 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Thesis

* Groschupf KD. Ph.D. (1983). "Comparative study of the vocalizations and singing behavior of four Aimophila sparrows". Virginia Polytechnic Institute and State University, United States -- Virginia.
* Morrison SA. Ph.D. (2001). "Demography of a fragmentation-sensitive songbird: Edge and ENSO effects". Dartmouth College, United States -- New Hampshire.
* Wimer MC. M.S. (1995). "Song variation in insular and mainland Rufous-crowned Sparrows". California State University, Long Beach, United States -- California.

Articles

* Baptista LF. (1973). "Leaf Bathing in 3 Species of Emberizines". Wilson Bulletin. vol 85, no 3. p. 346-347.
* Behle WH. (1976). "Mojave Desert Avi Fauna in the Virgin River Valley of Utah Nevada and Arizona USA". Condor. vol 78, no 1. p. 40-48.
* Bolger DT. (2002). "Habitat fragmentation effects on birds in southern California: Contrast to the "top-down" paradigm". Studies in Avian Biology. vol 25, p. 141-157.
* Bolger DT, Patten MA & Bostock DC. (2005). "Avian reproductive failure in response to an extreme climatic event". Oecologia. vol 142, no 3. p. 398-406.
* Bolger DT, Scott TA & Rotenberry JT. (1997). "Breeding bird abundance in an urbanizing landscape in coastal Southern California". Conservation Biology. vol 11, no 2. p. 406-421.
* Borror DJ. (1971). "Songs of Aimophila Sparrows Occurring in the USA". Wilson Bulletin. vol 83, no 2. p. 132-151.
* Carson RJ & Spicer GS. (2003). "A phylogenetic analysis of the emberizid sparrows based on three mitochondrial genes". Molecular Phylogenetics & Evolution. vol 29, no 1. p. 43-57.
* Deviche P, McGraw K & Greiner EC. (2005). "Interspecific differences in hematozoan infection in sonoran desert Aimophila sparrows". Journal of Wildlife Diseases. vol 41, no 3. p. 532-541.
* Hardy JW. (1980). "The Oaxaca Sparrow Aimophila-Notosticta Has a Chatter Vocalization". Condor. vol 82, no 1.
* Hubbard JP. (1975). "Geographic Variation in Non-California Populations of the Rufous Crowned Sparrow". Nemouria. vol 15, p. 1-28.
* Miles DB. (1986). "A Record of Brown-Headed Cowbird Molothrus-Ater Nest Parasitism of Rufous Crowned Sparrows Aimophila-Ruficeps". Southwestern Naturalist. vol 31, no 2. p. 253-254.
* Morrison SA & Bolger DT. (2002). "Lack of an urban edge effect on reproduction in a fragmentation-sensitive sparrow". Ecological Applications. vol 12, no 2. p. 398-411.
* Morrison SA & Bolger DT. (2002). "Variation in a sparrow's reproductive success with rainfall: Food and predator-mediated processes". Oecologia. vol 133, no 3. p. 315-324.
* Morrison SA, Bolger DT & Sillett TS. (2004). "Annual survivorship of the sedentary Rufous-crowned sparrow (Aimophila ruficeps): No detectable effects of edge or rainfall in southern California". Auk. vol 121, no 3. p. 904-916.
* Parker SA & Stotz D. (1977). "An Observation on the Foraging Behavior of the Arizona Ridge-Nosed Rattlesnake Crotalus-Willardi-Willardi Serpentes Crotalidae". Bulletin of the Maryland Herpetological Society. vol 13, no 2.
* Patten MA & Bolger DT. (2003). "Variation in top-down control of avian reproductive success across a fragmentation gradient". Oikos. vol 101, no 3. p. 479-488.
* Pulliam HR & Mills GS. (1977). "The Use of Space by Wintering Sparrows". Ecology. vol 58, no 6. p. 1393-1399.
* Remsen JVJ & Cardiff S. (1979). "Aimophila-Ruficeps-Scottii New-Record Rufous-Crowned Sparrow in California USA". Western Birds. vol 10, no 1. p. 45-46.
* Spicer GS. (1977). "2 New Nasal Mites of the Genus Ptilonyssus Mesostigmata Rhinonyssidae from Texas USA". Acarologia. vol 18, no 4. p. 594-601.

External links

* [http://vireo.acnatsci.org/search.html?Form=Search&SEARCHBY=Common&KEYWORDS=rufous-crowned+sparrow&showwhat=images&AGE=All&SEX=All&ACT=All&Search=Search&VIEW=All&ORIENTATION=All&RESULTS=24 Rufous-crowned Sparrow photo gallery] VIREO
* [http://ibc.hbw.com/ibc/phtml/especie.phtml?idEspecie=9578 Rufous-crowned Sparrow videos] on the Internet Bird Collection