Rufous-crowned sparrow: Difference between revisions
m →Ecology and behavior: expand |
|||
| Line 83: | Line 83: | ||
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.<ref name=" Thorngate "/> This bird 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.<ref name="Thorngate"/> Nests are well hidden, as they are built near bushes or tall grasses or overhanging rock with concealing vegetation.<ref name="Thorngate"/> Once a sparrow chooses a nesting site, it tends to return to the site for many years.<ref name="Thorngate"/> It lays between two and five eggs at a time and typically only raises one brood a year, though some birds in California have been observed raising two or even three broods a year.<ref name="Thorngate"/><ref name=" MBR "/> In case of a nesting failure, replacement clutches may be laid.<ref name="Thorngate"/> The eggs are an unmarked, pale bluish-white.<ref name=" Kaufman "/> |
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.<ref name=" Thorngate "/> This bird 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.<ref name="Thorngate"/> Nests are well hidden, as they are built near bushes or tall grasses or overhanging rock with concealing vegetation.<ref name="Thorngate"/> Once a sparrow chooses a nesting site, it tends to return to the site for many years.<ref name="Thorngate"/> It lays between two and five eggs at a time and typically only raises one brood a year, though some birds in California have been observed raising two or even three broods a year.<ref name="Thorngate"/><ref name=" MBR "/> In case of a nesting failure, replacement clutches may be laid.<ref name="Thorngate"/> The eggs are an unmarked, pale bluish-white.<ref name=" Kaufman "/> |
||
Incubation of the eggs lasts 11 to 13 days and is performed solely by the female. The hatchlings are naked and quills do not begin to show until the third day. Only females brood the nestlings, though both parents may bring whole insects to their young. Once a young Rufous-crowned Sparrow leaves the nest after eight or nine days, it is still incapable of flight, though it can run through the underbrush. Juveniles tend to leave their parent's territory and move into adjacent habitat in fall or early winter. Males guard their territories year-round.<ref name="Thorngate"/> |
Incubation of the eggs lasts 11 to 13 days and is performed solely by the female. The hatchlings are naked and quills do not begin to show until the third day. Only females brood the nestlings, though both parents may bring whole insects to their young. Once a young Rufous-crowned Sparrow leaves the nest after eight or nine days, it is still incapable of flight, though it can run through the underbrush. Juveniles tend to leave their parent's territory and move into adjacent habitat in fall or early winter. Males guard their territories year-round.<ref name="Thorngate"/> Reproductive success varies strongly with annual rainfall,and is highest in wet [[El Niño]] years, since cool rainy weather reduces the activity of snakes, the main predator of the sparrow’s nests.<ref name= >{{cite journal || last= Morrison | first= Scott A. | coauthors= Bolger, Douglas T. | month= November | year=2002 | title= Variation in a sparrow's reproductive success with rainfall: food and predator-mediated processes | journal=Oecologia | volume=133 | issue=3 | pages=315–324 | url = | |format = | doi =10.1007/s00442-002-1040-3 | quotes = |}}</ref> |
||
==Conservation== |
==Conservation== |
||
Revision as of 16:37, 20 January 2009
| Rufous-crowned Sparrow | |
|---|---|
| |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Family: | |
| Genus: | |
| Species: | A. ruficeps
|
| Binomial name | |
| Aimophila ruficeps (Cassin, 1852)
| |
The Rufous-crowned Sparrow, Aimophila ruficeps, is a smallish 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. The Rufous-crowned Sparrow has at least twelve recognized subspecies. This bird has a brown back with darker streaks and gray underparts. The crown is rufous in color, and the face and supercilium are gray with a brown or rufous steak extending from each eye and a thick black malar streak.
This sparrow feeds primarily on seeds in the winter and insects in the spring and summer. The birds are often territorial, with males guarding their territory through song and displays. They are monogamous and breed during spring. Nests are cup-shaped, well hidden and typically hold two to five eggs. Though the bird is considered to be of Least Concern, some subspecies are threatened and one may be extinct.
Taxonomy
This bird belongs to the family Emberizidae, which consists of the American sparrows and Eurasian buntings. The American sparrows are seed-eating birds with conical bills, brown or gray plumage, distinctive head patterns, and are mainly found in the New World. Birds in the genus Aimophila tend to be medium-sized, live in arid scrubland, have long bills and tails as well as short, rounded wings, and build cup-shaped nests.[2]
The Rufous-crowned Sparrow was described in 1852 by John Cassin as Ammodramus ruficeps.[3] The derivation of the current genus name, Aimophila, is from aimos/ἀιμος, meaning "thicket", and -philos/-φιλος, meaning "loving".[4] The specific epithet is a literal derivation of the common name, derived from the Latin rufus, meaning "reddish" or "tawny", and -ceps, from caput, meaning "head".[5] The bird is also occasionally referred to colloquially as the Rock Sparrow because of its preference for rocky slopes.[6]
Subspecies
Twelve subspecies are generally recognized,[3] although sometimes up to eighteen are named.[7]
- A. r. ruficeps, the nominate subspecies, was described by John Cassin in 1852.[7] It is found in the coastal ranges of California and on the western slopes of the Sierra Nevada.[8]
- A. r. canescens was described by W.E. Clyde Todd in 1922.[7] It is found in southwestern California and northeast Baja California as far east as the base of the San Pedro Martir.[8] 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.[6]
- A. r. obscura was described by Donald R. Dickey and Adriaan Van Rossem in 1923.[7] It is found in the Channel Islands of California on Santa Cruz, Anacapa, and formerly Santa Catalina.[6][8] While the Santa Catalina population has not been observed since 1863, the subspecies seems to have recently colonized Anacapa Island.[6]
- A. r. sanctorum was described by Adriaan Van Rossem in 1947.[7] It is found on the Todos Santos Islands off the coast of northwest Baja California.[8] However, this subspecies has not been seen since the 1970s.[6]
- A. r. sororia was described by Robert Ridgway in 1898.[7] It is found in the mountains of southern Baja California, specifically the Sierra de la Laguna.[8]
- A. r. scottii was described by George Sennett in 1888.[7] It is found from northern Arizona to New Mexico south to northeastern Sonora and northwestern Coahuila.[8]
- A. r. rupicola was described by Adriaan Van Rossem in 1946.[7] It is found in the mountains of southwestern Arizona.[8]
- A. r. simulans was described by Adriaan Van Rossem in 1934.[7] It is found in northwestern Mexico from sotheastern Sonora and southwestern Chihuahua to Nayarit and northern Jalisco.[8]
- A. r. eremoeca was described by N. C. Brown in 1882.[7] It is found from southeastern Colorado to New Mexico, Texas, northern Chihuahua, and central Coahuila.[8]
- A. r. fusca was described by Edward William Nelson in 1897.[7] It is found in western Mexico from southern Nayarit to southwestern Jalisco, northern Colima, and Michoacan.[8]
- A. r. boucardi, described by Philip Sclater in 1867,[7] is found in eastern Mexico from southern Coahuila to San Luis Potosi, northern Puebla, and southern Oaxaca.[8]
- A. r. australis was described by Edward William Nelson in 1897,[7] and occurs in southern Mexico from Guerrero to southern Puebla and Oaxaca.[8]
Description
The Rufous-crowned Sparrow is a smallish sparrow at 5.25 inches (13.3 cm)* in length.[3][7] It has a brown back with darker streaks and gray underparts. Its wings are short, rounded, and brown and lack 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.[7] This sparrow also has a crown which ranges from rufous to chestnut in coloration, a feature which gives it its common name.[2] The bill is yellow and conical shaped.[7] The sparrow's throat is white with a dark stripe. Its legs and feet are pink-gray.[3] 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 fall season.[7]
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.[3] When threatened or separated from its mate, the sparrow makes a dear-dear-dear call.[9]
Distribution and habitat
This bird is found in the southwestern United States and Mexico from sea level up to 9,800 ft (3000 m), though it tends to be found between 3000 and 6000 feet (915–1828 m).[3][6] 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; its also found in a small region of northeastern Kansas, its most northeastern range. The range of this species is discontinuous and is made up of many small, isolated populations.[6] The Rufous-crowned Sparrow is a non-migratory species, though the mountain subspecies are known to descend to lower elevations during severe winters.[6] Male sparrows maintain and defend their territories throughout the year.[6]
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.[3] The Rufous-crowned Sparrow thrives in the open areas that result from an area being burned.[6]
Ecology and behavior
The average territory size of Rufous-crowned Sparrows in the chaparral of California ranges from 0.89 hectares (2.2 acres)* to 1.5 hectares (3.7 acres)*.[6] The density of Rufous-crowned Sparrow territories varies by habitat, including 2.5 to 5.8 territories per 40 hectares (99 acres)* of three- to five-year old burned chaparral to 3.9 to 6.9 territories for the same amount of coastal scrubland.[6] One pair tends to be supported by a territory, though birds without a mate have been seen sharing a territory with a mated pair.[6]
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 foraging flocks.[6]
Predators of adult sparrows include house cats and small raptors like Cooper’s and Sharp-shinned Hawks, American Kestrels and White-tailed Kites.[10] The nests may be raided by a range of species including mammals and repiles such as snakes, and nesting sparrows have been observed using three kinds of displays to distract potential predators; the rodent run, the broken wing, and the tumbling off the bush.[6]
Diet
This sparrow feeds primarily on small grass and forb seeds, fresh grass stems, and tender plant shoots during fall and winter.[6] During these seasons, insects such as ants, grasshoppers, ground beetles, spiders, 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.[9]
The Rufous-crowned Sparrow forages slowly on or near the ground by walking or hopping under shrubs or dense grasses.[6] 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.[9] During the breeding season, it gleans its food from grasses and low shrubs.[6] However, normally the species obtains its food by either pecking or less frequently scratching at leaf litter. This bird tends to forage in a small family group and in a limited area.[9]
It is unknown whether this species obtains all of its water needs 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.[6]
Reproduction
The Rufous-crowned Sparrow breeds in successional scrubland. Males attract a mate by singing on posts at the edge of their territories throughout the mating season. If singing males come within contact of each other, they may initially raise their crowns and face the ground to display this feature; if that fails to make the other bird leave, they stiffen their body, droop their wings, raise their tails, and stick their head straight out.[6] These birds are monogamous, taking only one mate at a time, and pairs often remain together for several years.[6]
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.[6] This bird 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.[6] Nests are well hidden, as they are built near bushes or tall grasses or overhanging rock with concealing vegetation.[6] Once a sparrow chooses a nesting site, it tends to return to the site for many years.[6] It lays between two and five eggs at a time and typically only raises one brood a year, though some birds in California have been observed raising two or even three broods a year.[6][7] In case of a nesting failure, replacement clutches may be laid.[6] The eggs are an unmarked, pale bluish-white.[9]
Incubation of the eggs lasts 11 to 13 days and is performed solely by the female. The hatchlings are naked and quills do not begin to show until the third day. Only females brood the nestlings, though both parents may bring whole insects to their young. Once a young Rufous-crowned Sparrow leaves the nest after eight or nine days, it is still incapable of flight, though it can run through the underbrush. Juveniles tend to leave their parent's territory and move into adjacent habitat in fall or early winter. Males guard their territories year-round.[6] Reproductive success varies strongly with annual rainfall,and is highest in wet El Niño years, since cool rainy weather reduces the activity of snakes, the main predator of the sparrow’s nests.[11]
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' population over the last ten years.[12] However, some of the local populations of this bird are threatened and declining in number.[6] 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 have not been observed since the early 1900s.[6] 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.[6]
References
- ^ Template:IUCN2006
- ^ a b Howell, Steve N.G.; Webb, Sophie (1995), A Guide to the Birds of Mexico and Northern Central America, New York: Oxford University Press, pp. 712–713, ISBN 0-19-854012-4
- ^ a b c d e f g Byers, Clive (1995). Sparrows and Buntings: A Guide to the Sparrows and Buntings of North America and the World. Pica Press. pp. 296–7. ISBN 1873403194.
{{cite book}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Holloway JE (2003). Dictionary of Birds of the United States: Scientific and Common Names. Portland, Oregon: Timber Press. p. 17. ISBN 0881926000.
- ^ Simpson, D.P. (1979). Cassell's Latin Dictionary (5 ed.). London: Cassell Ltd. p. 883. ISBN 0-304-52257-0.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae Thorngate, Nellie (2005). "California Partners in Flight Coastal Scrub and Chaparral Bird Conservation Plan Rufous-crowned Sparrow (Aimophila ruficeps)". California Partners in Flight. Retrieved 2008-01-19.
{{cite web}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ a b c d e f g h i j k l m n o p q r Gough, Gregory (2000-12-28). "Rufous-crowned sparrow Aimophila ruficeps". Patuxent Bird Identification InfoCenter. USGS Patuxent Wildlife Research Center. Retrieved 2007-01-18.
- ^ a b c d e f g h i j k l Clements, James F (2007). The Clements Checklist of Birds of the World Sixth Edition. Ithaca, NY: Comstock Publishing Associates. pp. 681–682. ISBN 978-0-8014-4501-9.
- ^ a b c d e Kaufman, Kenn (1996). Lives of North American Birds. Boston: Houghton Mifflin. p. 583. ISBN 0-618-15988-6.
- ^ Morrison, Scott A. (2004). "Annual survivorship of the sedentary rufous-crowned sparrow {Aimophila ruficeps): no detectable effects of edge or rainfall in southern California". The Auk. 121 (3): 904–916, .
{{cite journal}}: Cite has empty unknown parameters:|1=,|2=,|3=,|quotes=, and|month=(help); Unknown parameter|coauthors=ignored (|author=suggested) (help)CS1 maint: extra punctuation (link) - ^ Morrison, Scott A. (2002). "Variation in a sparrow's reproductive success with rainfall: food and predator-mediated processes". Oecologia. 133 (3): 315–324. doi:10.1007/s00442-002-1040-3.
{{cite journal}}: Cite has empty unknown parameters:|1=,|2=,|3=, and|quotes=(help); Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ "Species factsheet: Aimophila ruficeps". BirdLife International. 2007. Retrieved 2008-01-19.
Further reading
Book
- Collins, P. W. 1999. Rufous-crowned Sparrow (Aimophila ruficeps). In The 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.
- Morrison SA. Ph.D. (2001). Demography of a fragmentation-sensitive songbird: Edge and ENSO effects. Dartmouth College, United States.
- 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. 85 (3): 346–347.
- Behle, WH (1976). "Mojave Desert Avifauna in the Virgin River Valley of Utah Nevada and Arizona USA". Condor. 78 (1): 40–48.
- Bolger, DT (2002). "Habitat fragmentation effects on birds in southern California: Contrast to the "top-down" paradigm". Studies in Avian Biology. 25: 141–157.
- Bolger DT, Patten MA & Bostock DC (2005). "Avian reproductive failure in response to an extreme climatic event". Oecologia. 142 (3): 398–406.
- Bolger DT, Scott TA & Rotenberry JT (1997). "Breeding bird abundance in an urbanizing landscape in coastal Southern California". Conservation Biology. 11 (2): 406–421.
- Borror DJ (1971). "Songs of Aimophila Sparrows Occurring in the USA". Wilson Bulletin. 83 (2): 132–151.
- Carson RJ & Spicer GS (2003). "A phylogenetic analysis of the emberizid sparrows based on three mitochondrial genes". Molecular Phylogenetics & Evolution. 29 (1): 43–57.
- Deviche P, McGraw K & Greiner EC (2005). "Interspecific differences in hematozoan infection in sonoran desert Aimophila sparrows". Journal of Wildlife Diseases. 41 (3): 532–541.
- Hardy JW (1980). "The Oaxaca Sparrow Aimophila-Notosticta Has a Chatter Vocalization". Condor. 82 (1).
- Hubbard JP (1975). "Geographic Variation in Non-California Populations of the Rufous Crowned Sparrow". Nemouria. 15: 1–28.
- Miles DB (1986). "A Record of Brown-Headed Cowbird Molothrus ater Nest Parasitism of Rufous Crowned Sparrows Aimophila ruficeps". Southwestern Naturalist. 31 (2): 253–254.
- Morrison SA & Bolger DT (2002). "Lack of an urban edge effect on reproduction in a fragmentation-sensitive sparrow". Ecological Applications. 12 (2): 398–411.
- Morrison SA & Bolger DT (2002). "Variation in a sparrow's reproductive success with rainfall: Food and predator-mediated processes". Oecologia. 133 (3): 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. 121 (3): 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. 13 (2).
- Patten MA & Bolger DT (2003). "Variation in top-down control of avian reproductive success across a fragmentation gradient". Oikos. 101 (3): 479–488.
- Pulliam HR & Mills GS (1977). "The Use of Space by Wintering Sparrows". Ecology. 58 (6): 1393–1399.
- Remsen JVJ & Cardiff S (1979). "Aimophila ruficeps scottii New-Record Rufous-Crowned Sparrow in California USA". Western Birds. 10 (1): 45–46.
- Spicer GS (1977). "Two New Nasal Mites of the Genus Ptilonyssus Mesostigmata Rhinonyssidae from Texas USA". Acarologia. 18 (4): 594–601.
External links
- Rufous-crowned Sparrow photo gallery VIREO
- Rufous-crowned Sparrow videos on the Internet Bird Collection