California Partners in Flight Coastal Scrub and Chaparral Bird Conservation Plan

Black-chinned Sparrow (Spizella atrogularis)


Photo by James Gallagher, Sea and Sage Audubon


Prepared by Kirsten Winter (kwinter@fs.fed.us)

Cleveland National Forest

10845 Rancho Bernardo Road

Suite 200

San Diego, CA 92127

 

RECOMMENDED CITATATION

Winter, K. 2002. Black-chinned Sparrow (Spizella atrogularis). In The Coastal Scrub and Chaparral Bird Conservation Plan: a strategy for protecting and managing coastal scrub and chaparral habitats and associated birds in California. California Partners in Flight. http://www.prbo.org/calpif/htmldocs/scrub.html

SHORTCUTS

range map

action plan summary

references

SUBSPECIES STATUS:

There are four recognized subspecies:

S.a. caurina Miller 1929. San Francisco Black-chinned Sparrow. This subspecies occurs in the Coast Ranges of California from Mendocino and Lake Counties south to San Benito County (Grinnell and Miller 1944). Its overall coloration is generally darker gray than other races with fewer brown tones (Tenney 1997).

S.a. cana Coues 1866. California Black-chinned Sparrow. Found in the foothills of California from Monterey County on the coast, and Tehama County inland, south to San Diego County and mountains of Baja California: east to San Bernardino Mountains of Riverside County. This subspecies is smaller, with a shorter tail than evura or atrogularis; underparts gray with a brownish wash (Tenney 1997).

S.a. evura Coues 1866. Arizona Black-chinned Sparrow. Found in the White Mountains of east-central California south along east slope of Sierra Nevada and across Inyo, Panamint, and other desert ranges to New York and Providence Mountains of San Bernardino County, and in mountains of eastern Riverside County, Nevada, Arizona, Utah, and New Mexico. Paler overall with a more sandy brown back and a more restricted black chin patch (Tenney 1997).

S.a. atrogularis Cabanis 1851. Mexican Black-chinned Sparrow. Resident in central Mexican states. Darker overall coloration and more extensive black chin patch than northern races (Tenney 1997).

MANAGEMENT STATUS:

Black-chinned Sparrow is a Partners in Flight Watch List species.

DISTRIBUTION: (California)

HISTORICAL BREEDING DISTRIBUTION:

Grinnell and Miller (1944) state that the Black-chinned Sparrow, a summer resident, breeds in the mountains and foothills west of the deserts from Monterey and Mariposa County south to the Mexican border, and on the east and west slopes of the Sierra Nevada south of Mono Lake. Wheelock (1904) states that the Black-chinned Sparrow is a common summer visitor in the foothills of southern California, and wanders as far north as Alameda and Monterey Counties.

CURRENT BREEDING DISTRIBUTION:

Zeiner et al. (1990) report that Black-chinned Sparrows breed locally and uncommonly in the foothills bordering the Central Valley, and commonly in the mountains of Southern California. Lehman (1994) described Black-chinned Sparrows as common in open chaparral in the mountain and foothill areas in Santa Barbara County. Between 1992 and 1997, the Cleveland National Forest conducted point counts at 200 point locations for chaparral bird species. This study resulted in the detection of about 160 Black-chinned Sparrows each year, in the Pine Valley area of San Diego County (USDA Forest Service 1997).

Breeds regularly as far north as Lake and Mariposa County and irregularly to Shasta and Trinity Counties. Black-chinned Sparrow is reported as a rare summer resident below 4000' on the west slope, and an irregular rare summer resident below 7500' on the eastern Sierra slope (Gaines 1992). Black-chinned Sparrow is a rare and local summer resident in the White Mountains, recorded between 6750 and 7000' (Hall 1991).

Breeding Bird Atlas:

San Diego BBA - Between 1997 and 2002, Black-chinned Sparrow was "one of the commonest species on the steep chaparral-covered slopes so widespread in San Diego County's foothills and mountains. Rugged topography seems to be nearly as much a feature of the Black-chinned Sparrow's habitat as chaparral. The Black-chinned Sparrow is a summer visitor almost exclusively, being very rare in winter and even as a migrant away from its breeding habitat. The Black-chinned Sparrow occurs widely in San Diego County's foothills and mountains above 1500 feet elevation. Gaps are due to extensive grassland, as in Warner Valley, or forest, as in the Cuyamaca Mountains. The largest concentrations appear to be between 2500 and 5500 feet elevation on south-facing slopes." P. Unitt, in litt.

Orange County BBA - Black-chinned Sparrows are common in moderate to dense stands of chaparral and dense coastal sage scrub in the foothills and along the coast; they are most common in chamise chaparral above 1500 feet and also occur in Ceanothus and scrub oak chaparral (Gallagher 1997).

Los Angeles BBA - Black-chinned Sparrows breed mainly on the slopes of the San Gabriel Mountains, and may breed occasionally in the Santa Monica Mountains (Garrett 1994).

Monterey BBA - Between 1988 and 1992, Black-chinned Sparrows were detected as rare summer residents of the foothills and mountains in Monterey County, with an estimated population of about 100 pairs (Robersen and Tenney 1993).

Marin County BBA - Shuford (1993) reports that Black-chinned Sparrows are irregular summer residents and rare local breeders in Marin County. Black-chinned Sparrows occur in "invasions" at irregular intervals and are subsequently reported for 2-3 consecutive years as rare migrants or rare summer residents.

ECOLOGY:

AVERAGE TERRITORY SIZE:

No quantitative data on territory size. Pough (1957, in Tenney 1997) reported territories of 1.6 - 4.0 ha per singing male.

TIME OF OCCURRENCE AND SEASONAL MOVEMENTS

Black-chinned Sparrows are partially migratory. Northern populations are strongly migratory, while Mexican populations are mostly resident (Tenney 1997).

Arrival date on breeding grounds:

In San Diego County, birds arrive in late March (Unitt 1984). San Diego County bird atlas data collected between 1997-2002 showed that "During the atlas' term, first spring dates for the Black-chinned Sparrow ranged from 16 March (1997, two at Cowles Mountain, N. Osborn) to 26 March. Since 1980 spring arrival appears to have shifted a few days earlier than previously (cf. Unitt 1984). "The nesting schedule we observed during the atlas period agrees with published data (91 California egg dates 21 April-7 July, J. D. Newman in Austin 1968), but the species' breeding season can extend slightly later: a clutch near Guatay (P21) hatched between 17 and 19 July 1995 (USDA Forest Service 1997)" P. Unitt, in litt.

Black-chinned Sparrows arrive from late March to mid May further north (Harris 1991, Gaines 1992, Robersen and Tenney 1993, Shuford 1993, Lehman 1994, Gallagher 1997).

Departure date from breeding grounds:

In San Diego County, birds depart in August or September; September 19 is the latest reported departure date (Unitt 1984), although at least five individuals were detected overwintering in San Diego County during the Breeding Bird Atlas surveys of 1997-2002 (P. Unitt, pers. comm.)

Elsewhere, typical departure dates are in August, with several earlier records (Gaines 1992, Shuford 1993).

Spring migration period:

Approximately March through May (Tenney 1997).

Fall migration period:

Late August through early November (Small 1994).

Extent of wintering in CA:

At least five individuals were detected overwintering in San Diego County during the Breeding Bird Atlas surveys of 1997-2002; two records in the upper watershed of the San Diego River above El Capitan Reservoir, one southwest of El Capitan Dam, and two records from remote areas of the Anza-Borrego desert.(P. Unitt, pers. comm.). Two records of Black-chinned Sparrows overwintering in Santa Barbara County were reported by Lehman (1994).

Outside of California: Winters in southeast Arizona, southern New Mexico and Texas, and in Mexico (Tenney 1997).

MIGRATION STOPOVER NEEDS/CHARACTERISTICS:

Stop-over period:

Unknown.

Habitat use:

Observed using chaparral during migration through southern California (Newman 1968a)

Routes:

Seen in small numbers migrating through the Anza-Borrego Desert area in March through May (Massey 1998). The San Diego County bird atlas "recorded the species 12 times in spring in the Anza-Borrego Desert, mainly along the east base of the mountains, between 26 March and 24 May. Along the coast, the only records of migrants are of one in San Clemente Canyon on 27 April 1999 and one at Point Loma on the very late date of 5 June 2001" (P. Unitt in litt.).

Lehman (1994) reports a few fall and spring records from the southern coastal and foothill areas of Santa Barbara County.

FOOD HABITS

FORAGING STRATEGY:

In summer, gleans insects from inner foliage and ground (Weathers 1983); rarely captures insects in flight (Tenney 1997). In winter, extracts grass seeds from racemes, often while perched on shrubs (Tenney 1997).

DIET:

Major food items include larval insects in the summer (Weathers 1983) and seeds of grasses and forbs in the winter (Tenney 1997).


DRINKING:

In summer, it appears that Black-chinned Sparrows may obtain sufficient water from their food (Weathers 1983). In winter, they may fly considerable distances to water sources (Tenney 1997).

BREEDING HABITAT

NEST SUBSTRATE:

May use a variety of shrubs including chamise, sagebrush, ceanothus, buckwheat. In San Diego County, breeding bird atlas data collected between 1997 and 2002 revealed the following: "The species of shrub appears immaterial; in San Diego County, big sagebrush, manzanita, flat-top buckwheat, and chamise have all been noted as nest sites" (P. Unitt, in litt.)

HEIGHT OF NEST:

Nest height is typically 1 to 3 feet (Baicich and Harrison 1997).

HEIGHT OF PLANT:

No information.

NEST CONCEALMENT:

Nest is placed near the center of a dense shrub, well concealed by the canopy of the shrub (Tenney 1997).

VEGETATION SURROUNDING THE NEST:

Usually found on gentle to steep slopes, often on south-facing slopes. Found in moderately dense chaparral with occasional openings (Tenney 1997). Chamise (Adenostoma fasciculatum), Ceanothus sp., Scrub Oak (Quercus sp.), Manzanita (Arctostaphylos sp.), Sagebrush (Artemisia californica or Artemisia tridentata) are the dominant plant species in the canopy. In San Diego County, breeding bird atlas data collected between 1997 and 2002 revealed the following: "Though the big sagebrush (Artemisia tridentata) is not typically defined as chaparral, and the Black-chinned Sparrow is absent from the Great Basin where this shrub dominates, in San Diego County the sparrow uses this plant commonly. The Black-chinned Sparrow's use of coastal sage scrub, though, is only marginal. Outlying sites nearer the coast correspond to more isolated chaparral-covered hills. Along the desert slope the edge of the Black-chinned Sparrow's breeding range tracks the edge of the chaparral closely. The notable exception is in the stunted piñon woodland of the Santa Rosa Mountains, where the species is rare and possibly sporadic" (P. Unitt, in litt.).

NEST TYPE:

Cup of dried grasses, lined with fine grasses, fibers and hair. Outside diameter 4", height 2 ¾ ", depth 1 1/3 ", inside diameter 1 1/3" (Harrison 1979).

BREEDING BIOLOGY

TYPICAL BREEDING DENSITIES:

Densities vary with habitat type. The greatest densities have been reported in chaparral. Weathers (1983) reported 21.33 birds/40 ha in Deep Canyon.

DISPLAYS:

For territorial defense, male Black-chinned Sparrows may engage in short chases and sing or exchange alarm calls at an accelerated rate (Tenney 1997).

MATING SYSTEM:

Forms pairs after arrival on breeding grounds (Tenney 1997).

CLUTCH SIZE:

Usually 3-4, with a range of 2-5 eggs. Eggs are oval, pale blue, unmarked or with small scattered dark brown spots (Harrison 1979).

INCUBATING SEX:

Probably only the female incubates (Baicich and Harrison 1997).

INCUBATION PERIOD:

13 days (Baicich and Harrison 1997).

DEVELOPMENT AT HATCHING:

Altricial.

NESTLING PERIOD:

10 days (Wheelock 1904).

PARENTAL CARE:

Both sexes (Baicich and Harrison 1997).

POST FLEDGING BIOLOGY OF OFFSPRING:

Both parents attend fledglings.

POST BREEDING SOCIAL BEHAVIOR:

In late summer and fall, immature birds may forage in single-species or mixed-species flocks (Tenney 1997).

NUMBER OF BROODS:

Probably single-brooded. Later broods are thought to represent replacement nests after nest failure (Tenney 1997).

LANDSCAPE FACTORS

ELEVATION:

Occurs from near sea level to 7500' (Tenney 1997).

FRAGMENTATION:

Black-chinned Sparrows appear to be very sensitive to fragmentation, and are absent from habitat patches that are smaller than approximately 400 acres (J.Lovio, pers. comm..)

PATCH SIZE:

Minimum patch size appears to be about 400 acres (J. Lovio, pers. comm.). In San Diego County, in some years Black-chinned Sparrow is a common summer resident in isolated chaparral patches of approximately 1000 acres, as at Van Dam Peak and Black Mountain, near Poway.

DISTURBANCE (natural or managed):

May prefer recently burned areas, where chaparral is less than 10 years old (Grinnell and Miller 1944).

ADJACENT LAND USE:

No information.

BROOD PARASITISM:

Apparently a rare victim, with 3 records for California listed by Friedmann (1963). Of 31 Black-chinned Sparrow nests found around Pine Valley in 1995-1997, 2 were parasitized (USDA Forest Service 1997).

SENSITIVITY TO HUMAN-INDUCED DISTURBANCE:

A population in San Benito County is reported to be threatened by loss of habitat due to extensive mining and off-road vehicle use (Johnson and Cicero 1985). Grazing is reported to degrade chaparral habitat in Texas (Wauer 1974).

PESTICIDE USE:

No reported studies/information on this subject.

PREDATORS:

Little information. Egg and nestling predators may include garter snakes and scrub jays (Tenney 1997). Of 31 Black-chinned Sparrow nests found around Pine Valley in 1995-1997, 25% of nests in old-age chaparral (1 of 4 nests) were predated, while 67% (18 of 27 nests) in young-age chaparral were predated (USDA Forest Service 1997).

EXOTIC SPECIES INVASION/ENCROACHMENT:

No information.

WEATHER:

Climatic change and weather trends appear to be linked to population fluctuations, with increased numbers of Black-chinned Sparrows reported in wet years (Tenney 1997, J. Lovio pers. comm.).

DEMOGRAPHY AND POPULATION TRENDS

AGE AND SEX RATIOS:

No information.

PRODUCTIVITY MEASURE(S):

Of 31 Black-chinned Sparrow nests found around Pine Valley in 1995-1997, 25% of nests in old-age chaparral (1 of 4 nests) were predated, while 67% (18 of 27 nests) in young-age chaparral were predated (USDA Forest Service 1997). The remaining nests fledged young.

SURVIVORSHIP:

No information.

DISPERSAL:

No information.

POPULATION TREND:

BBS Trend Data: http://www.mbr-pwrc.usgs.gov/bbs/bbs.html

Range-wide, BBS trend data between 1980-2000 showed a decrease of 0.2% per year. For California, it showed a decrease of 2.2% per year. Due to small sample sizes, low detection rates, or high variability, these data should be used with caution (Sauer, J. R., J. E. Hines, and J. Fallon 2001).

MANAGEMENT ISSUES:

1. Life history is poorly known.

2. Migration routes and stopovers are not well understood.

3. Development of private inholdings could fragment habitat and introduce non-native predators (dogs, cats).

4. Some investigators have concluded that grazing may have a negative effect on breeding and wintering habitat.

5. Fire return intervals may affect habitat suitability. Black-chinned Sparrows appear to favor recently burned chaparral; however, type conversion of chaparral to grassland would render habitat unsuitable for the Black-chinned Sparrow.

ASSOCIATED SPECIES:

Ash-throated Flycatcher, Spotted Towhee, Western Scrub Jay, Bushtit, Bewick's Wren, Sage Sparrow, Lawrence's Goldfinch.

MONITORING METHODS AND RESEARCH NEEDS:

1. Complete life history studies, collect more information about breeding, diet and behavior.

2. Complete additional surveys and bird atlases to acquire more detailed information on the distribution and abundance of this species.

3. Band and/or collect genetic information from California populations and Mexican populations to determine where California birds overwinter.

4. Use GIS models to compare the distribution of Black-chinned Sparrows to landscape features such as fire history, vegetation type, etc. Use this information to prioritize lands for conservation.

5. Study the effects of grazing on Black-chinned Sparrows including possible direct effects on vegetation and indirect effects such as cowbird parasitism.

6. Study the habitat use of Black-chinned Sparrows, determine whether recently-burned areas are preferred. Investigate reproductive success rates in young and old stands of chaparral.

 

ACTION PLAN SUMMARY


SPECIES: Black-chinned Sparrow, Spizella atrogularis

STATUS: Partners in Flight Watch List species.

Four recognized subspecies at this time.

HABITAT NEEDS:

Densities vary with habitat type. The greatest densities have been reported in chaparral. Weathers (1983) reported 21.33 birds/40 ha in Deep Canyon.

The breeding range includes California, southern Nevada and southern Utah, Arizona, and New Mexico. Breeding range is typically occupied beginning in March through May, and ending in August or September.

Black-chinned Sparrows are migratory, overwintering in Mexico or in the deserts of the southwestern US (Texas, Arizona and New Mexico).

Habitat associations vary throughout the breeding range. Associated with brushy vegetation, usually chaparral or sage scrub. Habitat is moderately dense, often with openings created by rock outcrops.

Winter range in southwestern US and central Mexico consists of desert scrub dominated by mesquite, ocotillo, yucca.

During the breeding season, gleans insects from shrubs or low trees. During the winter, feeds on grass and forb seeds.

Open-cup nests are built in shrubs or trees at heights of 1 to 3 feet above the ground. Average clutch size is 3 to 4 eggs.

CONCERNS:

Part of the habitat occupied by the Black-chinned Sparrow in California is under state or federal management and protection. Much of the breeding range, in the mountains of California, is managed by the US Forest Service, the National Park Service, the Bureau of Land Management. The wintering range of the Black-chinned Sparrow is largely in Mexico. Threats to the habitat at this time are in privately owned foothill areas of California, where habitat is being lost to development.

Possible concerns include:

Development of private inholdings could fragment habitat and introduce non-native predators.

Life history is poorly known.

Migration routes and stopovers are not well understood.

Development of private inholdings could fragment habitat and introduce non-native predators (dogs, cats).

Some investigators have concluded that grazing may have a negative effect on breeding and wintering habitat.

Fire return intervals may affect habitat suitability. Black-chinned Sparrows appear to favor recently burned chaparral; however, type conversion of chaparral to grassland would render habitat unsuitable for the Black-chinned Sparrow.

OBJECTIVES:

Improve knowledge of the species' life history, distribution and status throughout its range.

Locate wintering grounds for birds that breed in California.

Increase understanding of the habitat needs of this species; use this information to conserve key areas.

Determine the effect of grazing on habitat.

Determine appropriate fire return intervals.

ACTION:

1. Complete life history studies, collect more information about breeding, diet and behavior.

2. Complete additional surveys and bird atlases to acquire more detailed information on the distribution and abundance of this species.

3. Band and/or collect genetic information from California populations and Mexican populations to determine where California birds overwinter.

4. Use GIS models to compare the distribution of Black-chinned Sparrows to landscape features such as fire history, vegetation type, etc. Use this information to prioritize lands for conservation.

5. Study the effects of grazing on Black-chinned Sparrows including possible direct effects on vegetation and indirect effects such as cowbird parasitism.

6. Study the habitat use of Black-chinned Sparrows, determine whether recently-burned areas are preferred. Investigate reproductive success rates in young and old stands of chaparral.

REFERENCES:

Baicich, P.J. and C. J. O. Harrison. 1997. A guide to the nests, eggs, and nestlings of North American birds. 2nd ed. Academic Press, London,UK. 347 pp.

Cabanis, J.L. 1851. Museum Heinaenum. Vol. 1. Mexico, D.F.

Coues, E. 1866. List of the birds of Fort Whipple, Arizona. Proc. Acad. Nat. Sci. Phila. 18: 39-100.

Friedmann, H. 1963. Host relations of the parasitic cowbird. US. Natl. Mus. Bull. No. 233.

Gaines, D. 1992. Birds of Yosemite and the East Slope. Artemisia Press, Lee Vining, CA.

Gallagher, S.R. ed. and primary author. 1997. Atlas of Breeding Birds of Orange County. Sea and Sage Press, Irvine, CA.

Garrett, K. 1994. Bird species accounts, in Atlas Handbook for the Los Angeles County Breeding Bird Atlas. Natural History Museum of Los Angeles, Los Angeles, CA.

Garrett, K. and J. Dunn. 1981. Birds of southern California: status and distribution. Los Angeles Audubon Society, Los Angeles, California.

Grinnell, J. and A.H. Miller. 1944. The distribution of the birds of California, pp.367-369. Pacific Coast Avifauna no. 27. Cooper Ornithological Club, Berkeley, CA.

Hall, C.A. ed. Natural History of the White-Inyo Range. University of California Press. Berkeley and Los Angeles, CA.

Hamilton, R.A. and D.R. Willick. 1996. The birds of Orange County: status and distribution. Sea and Sage Press, Sea and Sage Audubon Society, Irvine, CA.

Harris, 1991. Birds of northwestern California. Humboldt Univ. Press, Arcata, CA.

Harrison, H. 1979. Western Bird Nests, Peterson Field Guides. Houghton Miflin Co, NY, NY. 279. pp.

Johnson, N.K. and C.Cicero. 1985. The breeding avifauna of San Benito Mountain, California: Evidence for change over a half-century. Western Birds 16: 1-23.

Lehman, P.E. 1994. The Birds of Santa Barbara County, California. Vertebrate Museum, University of California, Santa Barbara.

Lovio, J. 2002. Pers. comm. Senior Biologist, TAIC Consultants, San Diego, CA.

Massey, B. 1998. Guide to Birds of the Anza- Borrego Desert. Anza Borrego Desert Natural History Association, Borrego Springs, CA. 292 pp.

Miller, A. H. 1929. A new race of the Black-chinned Sparrow from the San Francisco Bay district. Condor 31: 205-207.

Newman. J.D. 1968a. Arizona Black-chinned Sparrow. Pp. 1241-1246 in Lifr histories of cardinals, grosbeaks, buntings, towhees, finches, sparrows, and their allies. (O.L. Austin, ed.) U.S. Nat. Mus. Bull. 237.

Pough, R.H. 1957. Audubon western bird guide: land, water and game birds. Doubleday, Garden Press, New York.

Robersen , D. and C. Tenney, eds. 1993. Atlas of the Breeding Birds of Monterey County. Monterey Peninsula Audubon Society, Monterey, CA. 438 pp.

Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.

Shuford, W.D. 1993. The Marin County Breeding Bird Atlas. California Avifauna Series 1. Bushtit Books, Bolinas, CA.

Small, A. 1994. California Birds, their status and distribution. Ibis Publishing Co, Vista, CA.

Tenney, C.R. 1997. Black-chinned Sparrow (Spizella atrogularis). In The Birds of North America, vol. # 270 (A. Poole and F. Gill, eds.). The Academy of
Natural Sciences, Philadelphia, PA

Unitt, P. 2002. Personal communication. Curator, Dept. Birds and Mammals, San Diego Natural History Museum, San Diego, CA.

Unitt, P. 1984. Birds of San Diego County. San Diego Natural History Society.

USDA Forest Service. 1997. Chaparral bird study. Cleveland National Forest files, San Diego, CA.

Wauer, R. H. 1974. Changes in the breeding avifauna within the Chisos Mountains system. Transactions of the symposium on the biological resources of the
Chiricahua desert region. Sul Ross State Univ., Nat. Park Service 1977:597-608.

Weathers, W. 1983. Birds of Southern California's Deep Canyon. Univ. of Calif. Press, Berkeley and Los Angeles, CA.

Wheelock, I.C. 1904. Birds of California. A.C. McClurg and Co, Chicago, IL.

Zeiner, D.C., W. Laudenslayer, Jr., K. Mayer, and M. White, eds. 1990. California's wildlife, Vol. 2: Birds. California Department of Fish and Game, Sacramento, 732 pp.