Rails, Gallinules, and Coots — Family Rallidae
Yellow Rail Coturnicops noveboracensis
The Yellow Rail lives in dense marshes of grass. It is extremely secretive and one of the most difficult North American birds for the human observer to see. It has also declined greatly, at least in its frequency as a winter visitor to California. From southern California there are only three recent records, one for San Diego County, all of birds lost in unsuitable urban habitat.
Winter: The single record for San Diego County is of one found alive on a city street in a recently developed area of north Santee (O12) before dawn on 16 December 1998. The bird was exhausted or sick; though it was brought to rehabilitators at Project Wildlife it died later that day and is now preserved as SDNHM 50186. The only other two Yellow Rails known from southern California since 1917 resulted from similar episodes in Santa Barbara and in Manhattan Beach near Los Angeles (Rottenborn and Morlan 2000, Erickson and Hamilton 2001).
Black Rail Laterallus jamaicensis
One of the earliest casualties of the decimation and degradation of San Diego County’s wetlands was the Black Rail, now extirpated. The California Department of Fish and Game has listed it as threatened statewide; small numbers persist only in the San Francisco Bay area, at Bodega, Tomales, and Morro bays, in the Imperial Valley, and along the lower Colorado River. The Black Rail was last known to nest in San Diego County in 1954; since then, only a dwindling number of vagrants has reached San Diego County, last in 1983.
Breeding distribution: Early in the 20th century, the Black Rail occurred widely if possibly irregularly in San Diego County’s coastal wetlands. It was known best from the tidal marshes of San Diego Bay, especially the estuary of the Sweetwater River (T10/U10), where Ingersoll (1909) estimated 30 pairs in 1908. “During some seasons, [E. E. Sechrist] estimated breeding populations of 25 to 30 pairs, [but] during other seasons he was unable to locate the species at all” (Willett 1933). The Black Rail was probably resident also at Mission Bay, where one was collected 22 June 1908, and in the Tijuana River estuary, where one was collected in November 1908 (Stephens 1909). In northern San Diego County, nesting was documented only at Los Peñasquitos Lagoon (N7; 28 May 1952, eggs collected, WFVZ 17222), but Stephens reported a specimen also from Encinitas 8 December 1886 (SDNHM 148), which was probably shot at nearby San Elijo or Batiquitos lagoons.
In 1974, Paul Jorgensen discovered Black Rails at Carrizo Marsh (O29) in the Anza–Borrego Desert, with six to ten on 18 and 19 May and 8 June 1974 (AB 28:949, 1974). Four were detected 27 June 1976 (AB 30:1003, 1976), but the following September flooding from tropical storm Kathleen destroyed the marsh, and saltcedar dominated its recovery. Despite many searches, no Black Rails have been found there since 1976.
Nesting: San Diego Bay was the first known and long the only proven site of Black Rail nesting in the western United States. The birds built their nests in marshes of pickleweed, either on the ground underneath the pickleweed (and thus subject to flooding by high tides) or elevated within the pickleweed, though still screened under its canopy. See Huey (1916) for a photo of a nest and an account of his hunt for the birds and their nests. Egg dates (39) ranged from 12 March to 9 June.
Migration: Although the California subspecies of the Black Rail is nonmigratory, the birds do disperse across unsuitable habitat. Early records of such dispersers are of one killed by flying against the lighthouse on Point Loma 4 August 1876 (Grinnell et al. 1918) and another picked up under the towers of the former Chollas Heights Naval Radio Station (R11) 30 August 1929 (Gander 1930; SDNHM 12710).
Winter: Since 1970, the only reports of the Black Rail in San Diego have been of vagrants in the nonbreeding season: one at San Elijo Lagoon (L7) 28 October 1973 (A. Fries), another there 21 February 1983 (L. R. Santaella, AB 27:338, 1983), and one heard at a pond in San Felipe Valley near Paroli Spring (I21) 19 December 1983 (P. Unitt).
Conservation: Factors contributing to the Black Rail’s extirpation from San Diego County include the destruction of most salt marsh habitat and probably water pollution and an increase in predators. For refuge during high tides, Black Rails need a buffer of upland habitat, now practically eliminated around San Diego County’s salt marshes. Around San Francisco and Tomales bays, where such a buffer is reduced, at high tide the rails become prey to Great Blue Herons, Great Egrets, Northern Harriers, Short-eared Owls, and gulls (Evens and Page 1986). The remaining population in southeastern California depends largely on seeps from irrigation canals, so efforts to improve the efficiency of water distribution by lining canals and pumping leaked water back into them reduces or eliminates Black Rail habitat (Evens et al. 1991).
Taxonomy: The California Black Rail, L. j. coturniculus (Ridgway, 1874), has a thinner bill, darker underparts, and more extensive chestnut on the nape than the subspecies of the eastern United States.
Clapper Rail Rallus longirostris
Recognized as endangered since the inception of the formal lists in 1970, the Light-footed Clapper Rail numbers only about 100 pairs in San Diego County. Once common in southern California’s coastal salt marshes, especially where cordgrass dominates, the rail was decimated as these marshes were filled and degraded. The Tijuana River estuary is an especially critical site; only Newport Bay in Orange County supports more Light-footed Clapper Rails. In spite of its precariously low numbers and continuing habitat degradation, the Clapper Rail retains some flexibility: it recovered from a population crash in the 1980s, and few individuals have colonized some new brackish or freshwater sites.
Breeding distribution: Richard Zembal has led spring censuses of the Light-footed Clapper Rail throughout its U.S. range annually since 1980, mapping calling birds to maximize precision (Zembal and Massey 1981). His effort has yielded an almost exhaustive inventory of the subspecies’ population and history of its fluctuations (Figure 11). In San Diego County, the sites where Zembal has found the rail, from north to south, are as follows. Data are from his surveys (Zembal and Hoffman 2002b) except as noted.
Cockleburr Canyon mouth (G4): one pair in 1982, none since.
Santa Margarita River estuary (G4): one or two pairs 1982–88, unpaired individuals in 1993 and 1997, two individuals on 16 April 1999 (P. A. Ginsburg), one pair in 2002.
San Luis Rey River mouth (H5): unpaired individual in 1990, one pair in 1992, none since.
Guajome Lake (G7): one pair in 1983, two in 1984, one individual on 25 June 2001 (K. L. Weaver).
Buena Vista Lagoon (H5/H6): One individual in 1990, two pairs in 1991, and present continuously since, with up to seven pairs in 1997.
Agua Hedionda Lagoon (I6): Up to seven pairs 1980–85, then absent until 1997; up to two pairs 1997–2002.
Batiquitos Lagoon (J7): Unmated individuals 1990–91, then present continuously 1993–2002, with up to three pairs in 1999, 2001, and 2002.
San Elijo Lagoon (L7): Sporadic before 1981 (King et al. 1987), then present almost continuously since, with up to eight pairs in 1997 but only one pair in 2000 and 2001.
San Dieguito River estuary (M7): Unmated individuals in 2000 and 2001.
Los Peñasquitos Lagoon (N7): One pair in 1988, sporadic unmated individuals 1989–93, one or two pairs 1994–2002.
Kendall–Frost Marsh, Mission Bay (Q8): Regular site, maximum 24 pairs in 1984, as few as one pair in 1996—trend is decreasing.
San Diego River flood-control channel (R8): Absent in only two years 1981–2002, maximum six pairs in 2002.
Famosa Slough (R8): Two pairs in 1995 only.
Paradise Creek marsh, National City (T10): Up to three pairs 1980–84, one in 1992, one in 1995, two in 1996, but only sporadic visitors since (one on 19 August 2000, T. A. Godshalk).
Sweetwater River estuary, including E and F Street marshes (U10): Regular site, maximum 17 pairs in 1984, minimum 2 in 1990.
J Street marsh (U10): One pair in 1981 and 2000 only.
Otay River mouth (along edge of salt works; U10): Up to five pairs 1980–86; up to three pairs 1995–2002, but only one pair 1999–2002.
South Bay Marine Biology Study Area (U10): Up to five pairs 1980–93; subsequently only one pair in 1997 and 1998.
Tijuana River estuary (V10): Up to 41 pairs 1980–84, crash to zero in 1985, gradual recovery beginning in 1986, reaching a maximum of 80 pairs in 1999.
Dairy Mart ponds, Tijuana River valley (V11): One pair 1988 and 1993, unmated individuals 1989–92, one bird 28 May 2001 (G. McCaskie).
Three additional freshwater sites not covered by Zembal have also come to light. The most significant is that in the Sweetwater River at Interstate 805 (T11), where the birds have been present at least since 1997, with up to six individuals 27 March 1998 (P. Famolaro). In San Dieguito Valley, along San Dieguito Road at the northeast corner of the Fairbanks Ranch Country Club (M8), the Clapper Rail has been found regularly since 1998; records from the breeding season are of one on 16 May 1999 (P. Unitt) and one on 1 April 2001 (M. and B. McIntosh). Finally, one was calling along the Otay River between Beyer Boulevard and Beyer Way (V11) 25 April 1999 (P. Unitt).
Nesting: Described in detail by Massey et al. (1984). Clapper Rails prefer to nest in tidal marshes where cordgrass dominates, building their nests largely of the hollow cordgrass stems and weaving the nest around upright cordgrass stems. Thus the nest can float with the changing tides while remaining attached in place. The nest is typically equipped with a ramp leading to the ground and a canopy of live cordgrass woven over the nest, screening it. If insufficient cordgrass is available, the birds will build under pickleweed or a tumbleweed blown into the marsh. Nests in freshwater marshes lack a canopy. Birds obliged to nest outside of low marshes, away from cordgrass, suffer more predation.
April and May represent the peak of the Light-footed Clapper Rail’s nesting season, but eggs have been collected as early as 6 March (WFVZ), and active nests with eggs have been seen as late as 15 July, meaning laying no earlier than late June (P. D. Jorgensen).
Migration: The Light-footed Clapper Rail is nonmigratory, and the site tenacity of adults is high. But young birds disperse from their natal marshes, as attested by rare sightings in unsuitable habitat, recolonization of some sites following extirpation, and the rail banded in September 1982 at Newport Bay observed the following September at Seal Beach, Orange County, 13.5 miles away (Zembal et al. 1985).
Winter: There is no evidence for the Clapper Rail’s range or numbers in San Diego County being any different in winter than in summer. We found the species occasionally at some of the same freshwater localities in winter as in summer: San Dieguito Valley (up to two on 28 February 2000, R. T. Patton), Sweetwater River near Interstate 805 (up to two on 19 December 1998, L. J. Hargrove), and the Dairy Mart ponds (one on 15 December 2001, G. McCaskie).
Conservation: The elimination of 90–95% of southern California’s coastal wetlands was the primary factor reducing the Clapper Rail to an endangered species. Currently, deliberate destruction has been halted, but serious habitat degradation continues. Siltation of lagoons and estuaries accelerated greatly with the development of their watersheds, leading to conversion of low marsh with cordgrass ideal for the rails into high marsh of marginal use to them. The fills supporting the railroad and freeway crossing the lagoons of northern San Diego County constrict tidal flushing, compounding the problem of siltation. Restoration of tidal flow at San Elijo and Batiquitos lagoons has enhanced these sites from the rail’s perspective. But at Los Peñasquitos Lagoon, home to over 100 Clapper Rails in 1968, much former marsh is now upland. In the Tijuana estuary, debris as well as massive quantities of silt washes in from the Mexican side of the border. Closure of the estuary’s mouth led to the marsh’s flooding and the population crash of 1985; recovery after reopening of the estuary took six years.
The limited extent of marsh dominated by cordgrass appears to be the primary current factor preventing the population’s recovery. Although the numbers in the Tijuana estuary have increased, those at Kendall–Frost and the Sweetwater estuary have decreased, leading to greater dependence on the Tijuana estuary. In spite of this estuary’s protection as a national wildlife refuge, problems there persist, including high levels of predation (Northern Harriers specializing on Clapper Rails) and human disturbance (from both illegal immigrants and the Border Patrol) as well as siltation and pollution.
The species’ colonization of new sites is a hopeful sign, but its biology suggests that freshwater sites are inferior to those in cordgrass-dominated salt marshes (Massey et al. 1984). Further study enabling comparison of the contributions of the freshwater and traditional saltmarsh sites is desirable.
Public acquisition of south San Diego Bay as the San Diego National Wildlife Refuge opens the possibility for restoration of some former salt marsh, a possibility that must be balanced against the needs of the many birds that take advantage of the salt works that replaced the marsh.
Yet another concern with the Clapper Rail is low genetic diversity and a low rate of genetic interchange among isolated populations. This concern is being addressed in part through captive breeding and transplanting young raised in captivity to sites away from the origin of their parents. The Chula Vista Nature Center and Sea World hatched and raised the Clapper Rail in captivity for the first time in 2001.
Taxonomy: The Light-footed Clapper Rail, R. l. levipes Bangs, 1899, is the subspecies resident from Santa Barbara County south probably at least to Estero de Punta Banda, Baja California. It differs from Clapper Rails farther north, north of Point Conception, mainly by its brighter orangish breast; it differs from those farther south, in central and southern Baja California, by its paler back.
Virginia Rail Rallus limicola
Being a secretive marsh bird, the Virginia Rail is difficult to observe and census accurately. It is noticed mainly by its peculiar series of grunts. Though generally uncommon, it is a widespread resident in freshwater and brackish marshes, even rather small ones, in all parts of San Diego County. The resident population is augmented in winter by migrants, which occasionally visit salt marshes as well.
Breeding distribution: Though the Virginia Rail’s distribution in an arid region like San Diego County is naturally very patchy, we found the species to be surprisingly widespread. It occurs in most if not all of the coastal wetlands of northern San Diego County, with up to eight at the mouth of Las Pulgas Creek (E3) 29 May 1999 (R. and S. L. Breisch) and six at the upper end of Agua Hedionda Lagoon (I6) 25 April 1999 (P. A. Ginsburg). It is perhaps more numerous at some of the lakes and ponds in the coastal lowland, with up to ten at O’Neill Lake (E6) 10 July 2001 and nine in the San Luis Rey River valley just north of Bonsall (F8) 6 July 2000 (P. A. Ginsburg). An effort focused on this species—surveys using taped recordings—could yield even higher numbers in good habitat (18 in San Pasqual Valley, J12, 26 July 1980, K. L. Weaver).
A region where the Virginia Rail was poorly known before the atlas study but proved relatively common was the Campo Plateau. Among the more notable sites for the species here are Boundary and Carrizo creeks from Jacumba north to Dubber Spur (five in square U28 on 22 April 1999 and five in T28 on 30 April 1999, with only a fraction of the habitat sampled, F. L. Unmack), Lake Domingo (U26; four on 20 April 1999, possibly gathering nest material 17 April 1998, F. L. Unmack), Tule Lake (T27; two on 1 April 1999, J. K. Wilson), La Posta Creek (two in square R24 on 12 July 2000, J. Larson; three in S23 on 20 June 1999, L. J. Hargrove), and Campo Creek in the Campo Indian Reservation (T24; two on 3 May 1998 and 5 May 2001, P. Unitt).
In the northern Anza–Borrego Desert the Virginia Rail is resident along Coyote Creek at Middle Willows (C22; up to four on 28 May 1999, P. D. Jorgensen) and Lower Willows (D23; up to six on 1 April 2001, R. and S. L. Breisch; chicks on 25 July 1995, P. D. Jorgensen in Massey 1998) and along San Felipe Creek from above Scissors Crossing (J22; up to two on 21 July 2002, J. R. Barth) and Sentenac Ciénaga (J23; at least eight on 3 May 1978, P. D. Jorgensen, but no more than one during the breeding season 1997–2002). At Carrizo Marsh the Virginia Rail is irregular or a recent extirpation, found regularly until 1994 but not 1997–2001 (P. D. and M. C. Jorgensen). At other desert sites it is more likely a winter visitor only.
Nesting: The Virginia Rail proved to be one of the most difficult species for us to confirm breeding. All our confirmations were of chicks accompanying their parents, at the mouth of Las Pulgas Creek 29 May 1999 (R. and S. L. Breisch), at San Elijo Lagoon (L7) 10 May 1998 (G. Rebstock), and in Carmel Creek at El Camino Real (N8) 26 June and 12 July 2001 (S. Scatolini). The nests are well hidden in flooded marshes, touching the water or elevated only slightly above it (Conway 1995). Egg sets collected in San Diego County number only five, 9 April–20 May. The chicks in late July at Lower Willows suggest laying as late as early to mid June.
Migration: The timing of Virginia Rail migrations is still poorly known because the birds are difficult to census accurately and few sites have been surveyed consistently through the year. Data from the Anza–Borrego Desert suggest that migrants arrive in numbers by 16 September (1978, 25 near Scissors Crossing, P. D. Jorgensen) and are still moving on 8 April (1998, four at the Borrego Springs sewage ponds, H25, H. L. Young, M. B. Mosher).
Winter: In winter the Virginia Rail is somewhat more widespread than in the breeding season and invades tidal salt marshes in small numbers (two at Kendall–Frost Marsh, Q8, 2 January 1987, P. Unitt; two in the Tijuana estuary, V10, 20 December 1997, W. Mittendorff). Numbers reported by atlas participants in winter were no greater than in summer, but monthly surveys of San Elijo Lagoon revealed a distinct peak from October to January, with a maximum count of 17 on 4 November 1973 (King et al. 1987). The Virginia Rail is recorded in winter exceptionally as high as 4600 feet at Cuyamaca Lake (M20; one on 4 December 1998, A. P. and T. E. Keenan). In addition to the sites in the Anza–Borrego Desert where it summers, the Virginia Rail winters occasionally at sewage ponds in the Borrego Valley (up to two on 26 October 1992, A. G. Morley) and along Vallecito Creek between Mason and Vallecito valleys (M23/M24; up to three on 22 January 1999, P. K. Nelson). From 1985 to 1992, Massey and Evans (1994) recorded the Virginia Rail at the latter site from September to May only.
Conservation: As a marsh species, the Virginia Rail is subject to the many habitat disruptions affecting wetland birds. But because of the lack of surveys focused on it, data that could define a trend are insufficient. The elimination of natural marshes may be partly offset by artificial ponds and reservoirs. Carrizo Marsh has been badly degraded by the invasion of saltcedar, likely accounting for the rail’s apparent disappearance there.
Taxonomy: Nominate R. l. limicola Vieillot, 1819, is the only subspecies of the Virginia Rail in North America; others occur in South America.
Sora Porzana carolina
The Sora is the most migratory member of the rail family in southern California, now occurring as a winter visitor almost exclusively. Soras usually remain hidden in marshes, noticed only by sound. Though generally uncommon, they are widespread, visiting even small isolated marshes scattered in the mountains and desert. Formerly, San Diego County represented the southern tip of the Sora’s breeding range, and rare stragglers still occur in summer, and but there has been no confirmation of nesting here for 50 years.
Winter: The Sora’s distribution in San Diego County is concentrated in the northwest, where the coastal lagoons and ponds in the low-lying valleys offer more habitat than in the rest of the county. Most of the larger numbers were reported from this area, such as five in the Santa Margarita River valley, Camp Pendleton (F5) 1 December 2001 (P. A. Ginsburg), five at the mouth of Agua Hedionda Creek (I6) 19 December 1999 (P. A. Ginsburg), seven in San Dieguito Valley (M8) 27 December 1998 (P. Unitt), and five at Los Peñasquitos Lagoon (N7) 1 March 1998 (D. K. Adams). The Sora is less frequent in salt marshes than in brackish or freshwater ones but uses them in small numbers (four at Kendall–Frost Marsh, Mission Bay, Q8, 2 January 1987, P. Unitt).
The Sora occurs at least sporadically at marshes throughout the county, at elevations as high as 4100 feet at Twin Lakes, Cooper Canyon (C18; up to three on 6 February 2000, M. and B. McIntosh), 4500 feet in Thing Valley (Q24; one on 25 December 2001, J. R. Barth), and 5000 feet in Crouch Valley, Laguna Mountains (P22; one on 31 December 1998, P. Unitt). Our largest count from 1997 to 2002 was from such an isolated location, 12 at a pond in La Posta Creek just north of Interstate 8 (S23) 9 December 1998 (L. J. Hargrove).
In the Anza–Borrego Desert the Sora is more frequent as a migrant but still occurs as a rare winter visitor at both sewage ponds (e.g., two at Ram’s Hill, H25, 16 January 1999, P. D. Jorgensen) and natural oases (e.g., two at Sentenac Ciénaga, J23, 12 February 1999, R. Thériault).
Migration: Late August to early May is the Sora’s usual season in San Diego County. From 1997 to 2001 our dates for the species ranged from 27 August (1997, one at O’Neill Lake, E6, P. A. Ginsburg) to 11 May (1999, two in McCain Valley, R26, L. J. Hargrove). Extreme dates are difficult to ascertain because of occasional summering birds, but one at Hillsdale near El Cajon (Q14) 7 August 1951 (SDNHM 31214) and one found dead in the driveway of a house near the Borrego Sink (G25) 15 August 1994 (ABDSP database) were away from possible breeding habitat.
Possibly because of increased calling in spring, King et al. (1987) noted numbers of Soras at San Elijo Lagoon more than twice as large in March and April than from September to January. Concentrations of spring migrants have been noted occasionally at oases in the Anza–Borrego Desert, up to at least eight at Sentenac Ciénaga 3 May 1978 and at least six Carrizo Marsh (O29) the following day (P. D. Jorgensen).
Migrants occasionally strike power lines or other obstacles while flying through urban areas. These casualties occur during the winter as well as during spring and fall migration, suggesting the birds cross unsuitable habitat at night regardless of season (e.g., one at Coronado, S9, 17 January 1982, SDNHM 42219).
Breeding distribution: The only published account of Sora breeding in San Diego County is Sharp’s (1907) statement that “for several years a pair has nested in nearly the same locality on the river below Escondido. Each year the nest was discovered before the clutch of eggs was complete and on going back a few days later the nest was always empty.” The San Bernardino County Museum has an egg set collected at National City (T10) 20 April 1935 and another from “San Diego County” without more precise locality collected 4 May 1954. A. M. Ingersoll (in Willett 1912) believed Soras bred occasionally “in the vicinity of San Diego,” and Stephens (1919a) wrote that the species was “occasional throughout the year.”
More recent summer records are few, with no suggestion of breeding. For example, King et al. (1987) noted single individuals only three times in June or July on monthly censuses of San Elijo Lagoon, 1973–83. The only June or July record during the atlas period was of one in the San Luis Rey River just north of Indian Flats (D19) 2 June 2001 (L. J. Hargrove).
Conservation: Early in the 20th century, the Sora was common year round in coastal southern California (e.g., Willett 1912), though probably more so in the Los Angeles basin and Orange County’s former Gospel Swamp than in San Diego County. Unfortunately, the breeding population was nearly eliminated by draining of marshes before it was well documented. Nevertheless, a few birds continue to breed at a few sites in Orange County (Hamilton and Willick 1996), so breeding in San Diego County remains possible.
The trend in the winter population is less clear but it too may be downward. For example, from 1976 to 1986, the Oceanside Christmas bird count, whose circle constitutes the core of the Sora’s range in San Diego County, averaged 17, but from 1997 to 2001 it averaged only six. The reduction of natural marshes in floodplains has likely been compensated partly, from the Sora’s point of view, by the installation of many ponds that are quickly colonized by aquatic plants.
Purple Gallinule Porphyrio martinicus
The Purple Gallinule is widespread in the American tropics but in the United States it breeds only in the Southeast. On the Pacific coast it is resident north only to the Mexican state of Nayarit. Thus California is far out of its normal range, and there are only three records for the state, one for San Diego County.
Migration: On 1 October 1961, San Diego County’s single and California’s first Purple Gallinule, a juvenile, struck a wire in a residential area of Point Loma (S7), where Fay Dalton picked it up. It died the next day and is now SDNHM 30289 (Huey 1962).
Common Gallinule or Moorhen Gallinula chloropus
The Common Gallinule (moorhen in British English) is an uncommon to fairly common resident of freshwater marshes in the coastal lowland. It favors areas with about an equal mix of emergent vegetation and open water. It frequents coastal wetlands if they are only slightly brackish but avoids salt water. It is nonmigratory in California but disperses occasionally; the atlas revealed the species to be a rare winter visitor outside its breeding range, at elevations up to 3500 feet.
Breeding distribution: In San Diego County, the Common Gallinule is strongly concentrated in the northwest, in the valleys of the Santa Margarita and San Luis Rey rivers and in the coastal lagoons. In the north county’s coastal wetlands, numbers are highest in lagoons lacking tidal influence, especially at the mouth of San Mateo Creek (C1; up to seven on 5 July 1997, P. D. Jorgensen) and in Buena Vista Lagoon (seven in the west basin, H5, 10 August 1999, M. Freda; 15 in the east basin, H6, 25 July 1999, L. E. Taylor, including young all these dates). At a few places a short distance inland the gallinule is fairly common, with up to 10 on O’Neill Lake (E6) 29 July and 21 August 1997 (P. A. Ginsburg), 12 on sewage ponds in the Santa Margarita River valley, Camp Pendleton (F5), 26 June 1999 (R. E. Fischer), and 13 at La Costa Country Club (J7) 10 May 2000 (C. C. Gorman).
Farther south, where ponds are fewer, the gallinule is scarcer and more scattered. Our only count during the breeding season of more that four individuals in central or southern San Diego County was of six along the Sweetwater River between Bonita and Sweetwater Dam (T12) 19 July 2001 (T. W. Dorman). Our only sites for the gallinule east of the coastal lowland were at 3300 feet at Sunshine Summit (D17; two at artificial ponds landscaping a mobile-home park, 3 June 2001, P. K. Nelson) and at 4100 feet at Twin Lakes, Cooper Canyon (C18; five, including young, 15 June 2000, M. and B. McIntosh).
Nesting: Common Gallinules nest within a marsh, often on flattened cattails. The nests are usually screened from view, so atlas observers reported only one (along the San Diego River in Mission Valley, R9, 1 May 1997, H. L. Young). Almost all of our confirmations of gallinule breeding were of young accompanying their parents; the precocial chicks leave the nest soon after hatching. Our dates for chicks ranged from 29 April to 16 August, implying egg laying from early April to early July.
Migration: The Common Gallinule is a nonmigratory species in California but occasionally disperses outside its usual range. Records of birds crossing atypical habitat are of one found dead near the Palomar Observatory (D15) 31 October 1983 (R. Higson, AB 38:246, 1984) and one found injured on Main Street in Otay (V11) 2 December 2002 (SDNHM 50753).
Winter: The gallinule is slightly more widespread in winter than spring and summer, reported in 27 atlas squares in winter but not the breeding season, versus 11 for the reverse. Unusually large numbers have been seen occasionally at O’Neill Lake (up to 30 on 13 December 1999, P. A. Ginsburg). Occasionally numbers at some other spots were notably higher than in the breeding season (up to 10 at the Dairy Mart pond, Tijuana River valley, V11, 18 December 1999, G. McCaskie). At sites where we missed the species in the breeding season, eight at Wilderness Gardens (D11) 7 December 1997 (M. B. Mosher) and eight on San Marcos Creek near Rancho Santa Fe Road (J8) 23 December 2000 (E. C. Hall) were our only counts of more than four. The gallinule could be an irregular resident at all these additional sites in the coastal lowland, however.
Before our atlas study, there were no winter records of the gallinule in San Diego County outside the coastal lowland, so it was a surprise that we accumulated ten from 1997 through 2002. Five of these were from southeast county from Potrero (U20) to Tule Lake (T27), all of single birds except for seven at Campo (U23) 3 February 1999 (D. C. Seals). Other sites were Pamo Valley (I15, two records, O. Carter), near Mesa Grande (H16; one on 15 December 1999, E. C. Hall), and near Descanso (P20; one on 15 February 2002, J. K. Wilson). The only record for the Anza–Borrego Desert is of one on a farm pond at the north end of the Borrego Valley (E24) 20 December 1998 (P. R. Pryde).
Conservation: The gallinule has never been very common in San Diego County; in spite of many disruptions to the county’s wetlands, there is no clear trend in the species’ numbers here. Most of the sites that it occupies now are not natural.
Taxonomy: Gallinula c. cachinnans Bangs, 1915, is the only subspecies of the Common Gallinule in North America. Many others occur in other parts of the species’ vast range.
American Coot Fulica americana
The American Coot is one of America’s most successful water birds, common in San Diego County as a breeding species and abundant as a winter visitor. An ability to graze on lawns preadapted the coot to urbanization, to some extent. Nesting birds need marshes around fresh or brackish water, but winter visitors spread to salt water and ponds with little surrounding vegetation.
Breeding distribution: The coot breeds throughout San Diego County’s coastal slope wherever there are freshwater marshes and ponds. Breeding birds are most numerous around lakes in the coastal lowland (up to 200 at Lake Hodges, K10, 14 June 1999, R. L. Barber; 100 at O’Neill Lake, E6, 19 April 1999 and 30 July 2001, P. A. Ginsburg) and at Buena Vista Lagoon (up to 318 in the west basin, H5, 10 August 1999, M. Freda). The lack of tidal influence and abundant cattail surrounding Buena Vista make it the best coot habitat among the county’s coastal wetlands. Nevertheless, the coot still breeds to some extent in brackish lagoons, as attested by two chicks on the north shore of Batiquitos Lagoon (J7) 4 May 2001, after the restoration of tidal flushing there (C. C. Gorman).
If it contains water, even San Diego County’s highest lake, Big Laguna at 5400 feet (O23), supports breeding coots (up to 65 on 7 July 2001, J. R. Barth). In the Anza–Borrego Desert, coots remain into spring only sporadically at ponds in the Borrego Valley. During the atlas period such records were of single individuals only, with only two later than 17 April (E24 and G24; 4 and 6 May 2000, P. D. Ache). The coot has been confirmed nesting in the Anza–Borrego Desert just once, on 19 May 1974, when a newly hatched chick was seen with its parents at Oso Ranch in the north Borrego Valley (E24; ABDSP database).
Nesting: The American Coot nests over water in matted vegetation. Though the nest is often hidden within a marsh, the coot nests closer to edges than other California species of the family Rallidae, so atlas observers saw many more coot nests than they did of the other species. Chicks, however, accounted for most of our confirmations of coot breeding. Coots evidently begin nesting in the third week of March, as we noted chicks as early as 14 April; they leave the nest just a day or two after hatching. An occupied nest as late as 24 July translates to egg laying no earlier than 1 July. We observed young being fed by their parents as late as 2 September.
Migration: Coots begin moving into habitat where they do not breed as early as 11 August (1993, 16 in the south San Diego Bay salt works, V10, Stadtlander and Konecny 1994) but arrive gradually, perhaps not reaching full abundance until late October or early November (432 at Batiquitos Lagoon, J6/J7, 27 October 1997, Merkel and Associates 1998; 460 at San Elijo Lagoon, L7, 26 October 1992, P. Unitt). King et al. (1987) found that numbers at San Elijo Lagoon peaked from November to January. One coot at the Borrego Springs Country Club (G24) 5 September 1998 (P. D. Jorgensen) provided the species’ the earliest fall record for the Anza–Borrego Desert.
In spring, wintering coots remain common until early April (667 at Batiquitos Lagoon 3 April 1997; 402 there the following day, Merkel and Associates 1998) but depart soon after that. Almost all are gone after the third week of April. Migrants have been noted in the Anza–Borrego Desert from 21 March (2001, two in Vallecito Valley, M24, P. K. Nelson) to 17 April (1999, one at the Borrego sewage ponds, H25, H. L. Young, M. B. Mosher).
A small number of nonbreeders remains on salt water through the summer (three sightings of single individuals on central San Diego Bay 9 May–27 June 1994, Preston 1995; three at Shelter Island, S8, 5 July 1998, P. Unitt).
Winter: Huge numbers of coots migrate into San Diego County for the winter. Even at the species’ prime breeding sites, numbers are far higher in winter (up to 2100 in the west basin of Buena Vista Lagoon 26 December 1998, M. B. Stowe; 2000 at O’Neill Lake 1 and 4 December 2000, P. A. Ginsburg). The coot is no more restricted elevationally in winter than in summer, with up to 150 at Big Laguna Lake 18 January 1998 (P. Unitt).
In the Anza–Borrego Desert wintering coots are restricted to ponds in the Borrego Valley, where they are irregularly common (highest count 70 in the Ram’s Hill development 20 December 1998 (R. Halford).
A habitat that coots exploit in winter but not summer is lawns (which they graze like cattle) near water (in which they take refuge from disturbance and predators). The landscaped shores of Mission Bay are especially attractive, accounting for our highest winter numbers (up to 2400 in the northeast quadrant of the bay, Q8, 21 December 1998, J. C. Worley). On sheltered salt water where lawns are not close by, the coot occurs in much smaller numbers. Around south San Diego Bay outside the salt works, Macdonald et al. (1990) had no daily count greater than 50. Within the salt works, Stadtlander and Konecny (1994) had no more than 10 wintering coots per weekly survey 1993–94, but from 1997 to 2001 Christmas bird counts in this area yielded up to 131 on 18 December 1999 (D. C. Seals et al.).
Conservation: Data to suggest a trend in numbers of coots breeding in San Diego County are insufficient. But as a winter visitor the species has likely increased, since it takes such advantage of reservoirs, ponds, cemeteries, and the county’s many and proliferating golf courses. Among San Diego County’s Christmas bird counts, results from Escondido and Anza–Borrego suggest an increase. The Anza–Borrego count averaged 5.6 coots from 1985 to 1996, 59.2 from 1997 to 2001. In some places in California, coots have been considered a nuisance and subjected to pest control (Brisbin and Mowbray 2002).
Taxonomy: Nominate F. a. americana Gmelin, 1789, is the subspecies of American Coot that covers the North American continent.