II SPECIES ACCOUNTS Andy Birch PDF of Channel Island Song Sparrow account from: Shuford, W. D., and Gardali, T., editors. 2008. California Bird Species of Special Concern: A ranked assessment of species, subspecies, and distinct populations of birds of immediate conservation concern in California. Studies of Western Birds 1. Western Field Ornithologists, Camarillo, California, and California Department of Fish and Game, Sacramento. California Bird Species of Special Concern CHANNEL ISLAND SONG SPARROW (Melospiza melodia graminea) Paul W. Collins Criteria Scores Santa Population Trend 15 Barbara County Range Trend 10 Ventura Population Size 5 County Range Size 10 Endemism 10 Population Concentration 10 Threats 10 Los Angeles San Miguel Is. Santa Cruz Is. County Anacapa Is. Santa Rosa Is. Santa Santa Barbara Is. Catalina Is. San Nicolas Is. San Clemente Is. Current Year-round Range Historic Year-round Range County Boundaries Kilometers 20 10 0 20 Current and historic (ca. 1944) year-round range of the Channel Island Song Sparrow, a California endemic; num- bers have declined greatly. Restricted to San Miguel and Santa Rosa islands, and formerly to Santa Barbara (up to the 1960s) and San Clemente islands (up to 1973). Song Sparrows on Santa Cruz Island are intermediate between adjacent mainland heermanni and island graminea. Song Sparrows of one or more mainland subspecies occur as occasional migrants to the Channel Islands. Channel Island Song Sparrow Studies of Western Birds 1:425–431, 2008 425 Studies of Western Birds No. 1 SPECIAL CONCERN PRIORITY Jones in press). Although some authorities consid- er Song Sparrows breeding residents on Anacapa Currently considered a Bird Species of Special Island (Grinnell and Miller 1944, AOU 1957, Concern (year round), priority 1. None of the Patten 2001), a review of all available records originally described endemic subspecies of the indicate that the species is only a casual spring Song Sparrow on the Channel Islands were and fall transient to this island (Collins and Jones included on prior special concern lists (Remsen in press). Song Sparrows from the mainland are 1978, CDFG 1992). occasionally reported during the fall and winter on other islands that currently do not support BREEDING BIRD SURVEY STATISTICS resident breeding populations. FOR CALIFORNIA Data inadequate for trend assessment (Sauer et HISTORIC RANGE AND ABUNDANCE al. 2005). IN CALIFORNIA Historically, Song Sparrows were resident on GENERAL RANGE AND ABUNDANCE four of California’s Channel Islands: San Miguel, The Song Sparrow (Melospiza melodia) is one of Santa Rosa, Santa Barbara, and San Clemente. the most widespread species of songbird in North Howell (1917) and Grinnell and Miller (1944) America, ranging from southern Alaska across found them numerous and widespread but of central and southern Canada south through the variable relative abundance among the islands. United States into northern (locally to central) Early ornithologists variously described them as Mexico and Baja California; a large part of “less common,” “common,” “fairly common,” and northern range occupied in summer only, much “abundant” on the islands. These observations, of mid-central and southern portion in winter however, were all made well after feral herbivores only (AOU 1998). In California, the species is had begun to alter the shrubby habitats occupied resident in much of the state except for the higher by Song Sparrows. The historic status of M. m. mountains and most of the southeastern deserts graminea varied among islands as reviewed here. away from the Salton Sink and Colorado River San Miguel Island. Most early observers valley (Grinnell and Miller 1944, Small 1994). Of reported Song Sparrows as “common” on San the 24 subspecies currently recognized, 9 occur in Miguel (Willett 1933, Howell 1917, Grinnell and California (Patten 2001, Arcese et al. 2002). Miller 1944), whereas Sumner and Bond (1939) The Channel Island Song Sparrow (M. m. described them as “abundant” on the main island graminea) is resident on two (formerly four) of and present and breeding on adjacent Prince the California Channel Islands and on Islas Los Island. Despite widespread vegetation stripping Coronados off northern Baja California (Patten from intensive grazing by feral European Mouflon 2001, Collins and Jones in press). Sheep (Ovis aries) during the 19th and early 20th Until Patten’s (2001) revision, which merged centuries, Song Sparrows apparently were still all of the island subspecies into a single endemic common on San Miguel through the 1940s. (M. m. graminea), Song Sparrows on the Channel Santa Rosa Island. In July 1892, C. P. Streator Islands were assigned to one of four endemic (unpubl. field notes, USNM) described Song subspecies: graminea on Santa Barbara, micronyx Sparrows on Santa Rosa as “common in the wood- on San Miguel, clementae on Santa Rosa and ed canyons about water”; other early observers San Clemente, and coronatorum on Islas Los considered them “common” or “fairly common” Coronados (Grinnell and Miller 1944, AOU (Howell 1917; H. H. Sheldon unpubl. field notes, 1957). Because Patten (2001) considered Song SBMNH; Grinnell and Miller 1944). Sparrows on Santa Cruz Island to be intermedi- Santa Barbara Island. Grinnell (1897) reported ate between adjacent mainland heermanni and the Song Sparrow as the “most abundant bird” on island graminea, this population is not discussed Santa Barbara; other early observers also termed further. it “abundant” (Howell 1917, Sumner and Bond 1939, Grinnell and Miller 1944). These estimates suggest that at least until the early 1940s Song SEASONAL STATUS IN CALIFORNIA Sparrow abundance on Santa Barbara Island had The Channel Island Song Sparrow is a sedentary, not been reduced substantially by the decline of year-round resident; the breeding season extends shrubby vegetation from farming activities, sheep from late February until mid-July (Collins and grazing, and feral European Rabbit (Oryctolagus 426 Species Accounts California Bird Species of Special Concern cuniculus) foraging that occurred from 1915 to Today, Song Sparrows are considered widespread 1938 (Sumner 1958, Stewart and Smail 1974). and “common” on this island (Kern et al. 1993). San Clemente Island. Various early observers Santa Rosa Island. Miller (1951) reported Song described Song Sparrows as “numerous,” “abun- Sparrows as “common” on Santa Rosa in 1950, dant,” or “common” on San Clemente (Grinnell and P. W. Collins (unpubl. field notes, SBMNH) 1897, Linton 1908, Howell 1917, Grinnell and described them as “common to abundant” in 1975 Miller 1944). Shrubby habitats inhabited by Song and 1976. Feral pigs (Sus scrofa) were eradicated Sparrows on San Clemente were adversely affected from Santa Rosa Island in 1993 (Lombardo and by feral herbivore grazing, which began there Faulkner 2002) and domestic cattle (Bos tarus) in the early 19th century (USDN 2001). Goats were removed in 1998 (NPS 1998). From 1993 (Capra hircus) apparently were kept under control to 1998, variable-circular-plot surveys recorded by hunting and by commercial sheep ranching an average of 0.68 birds per station (range = from 1860 until 1934, when ranching operations 0.38–1.14, SE 0.15) and detected these sparrows were stopped (Andrew 1998 in USDN 2001), at an average of 38.9% (range = 7.7%–66.7%) of which may account for Song Sparrows still being all stations (Fancy 2000). numerous on the island into the early 1940s. Santa Barbara Island. Despite the destruction Subsequently, however, goat numbers began to of much of their scrub and Coreopsis nesting habi- increase greatly, as did the impact of goats on the tat from clearing for farming and from browsing island’s vegetation and endemic avifauna (USDN by introduced European Rabbits, Song Sparrows 2001). were still present in reasonably high numbers at least through the spring of 1958 (Sumner 1958). RECENT RANGE AND ABUNDANCE A fire in 1959, however, destroyed most of the IN CALIFORNIA sparrows’ remaining habitat, and they disappeared from the island sometime during the 1960s Breeding populations of Song Sparrows on Santa (Philbrick 1972). Intensive surveys in the 1970s Barbara and San Clemente islands have been extir- (Hunt and Hunt 1974, Smail and Henderson pated as a result of vegetation stripping by feral 1974, J. Diamond unpubl. data, H. L. Jones herbivores and increased rates of predation from unpubl. data) and six years of intensive monitor- feral cats (Felis catus) and various native avian and ing surveys in the 1990s (Fancy 2000, Coonan mammalian predators (see map; Stewart and Smail et al. 2001) failed to locate any resident Song 1974). By contrast, Song Sparrows are apparently Sparrows. The Santa Barbara Song Sparrow (M. more widely spread today on San Miguel and m. graminea, sensu AOU 1957) was officially listed Santa Rosa islands than historically, in response to as extinct in 1983 (USFWS 1983). improvement of scrub habitats following removal San Clemente Island. The last documented of feral herbivores from these islands. sightings of the Channel Island Song Sparrow on San Miguel Island. Huber (1968) reported that San Clemente were of two birds seen on 24–27 Song Sparrows were “abundant” across the island. May 1968 (J. Diamond pers. obs.) and single In 1973, H. L. Jones considered them “very com- birds (possible migrants) at Wilson Cove on 9 mon” away from the barren western one-third of April 1972 and 14 April 1973 (Leatherwood and the island (Collins and Jones in press). Island- Coulombe 1972, H. L. Jones pers. obs.). Intensive wide estimates were 980–1200 birds in 1978 and surveys for this species in May 1974 failed to 2000 in 1986 (Collins 1979, Sogge et al. 1991). locate any resident birds (Stewart and Clow 1974). The last feral herbivores were removed from San Hence, the Channel Island Song Sparrow appears Miguel in the late 1970s. In the mid-1980s, to have been extirpated from San Clemente since Sogge and van Riper (1988) recorded densities the early 1970s. of 7.1 to 10.0 birds per ha on their study plots.