Tuesday, January 7, 2020
Santa Barbara Song Sparrow Facts
The Santa Barbara Song Sparrow (Melospiza melodia graminea, sensu) is a now-extinct subspecies of song sparrow that lived on Santa Barbara Island in California and was most closely related to the Channel Island Song Sparrow (Melospiza melodia graminea). It was one of the smallest of the 23 subspecies of song sparrows and had a perky short tail. Fast Facts: Santa Barbara Song Sparrow Scientific Name: Melospiza melodia graminea, sensuCommon Name: Santa Barbara Song SparrowBasic Animal Group: BirdSize: 4.7ââ¬â6.7 inches; wingspan 7.1ââ¬â9.4 inchesWeight: 0.4ââ¬â1.9 ouncesLifespan: 4 yearsDiet:à OmnivoreHabitat: On Santa Barbara Island, Channel Islands, CaliforniaPopulation: 0Conservation Status: Extinct Description There are 34 subspecies of song sparrows in the world: It is one of the most polytypic birds in North America, with a good deal of variation, especially in geographically restricted species. The Santa Barbara Song Sparrow resembled other similar subspeciesà and is described as most closely resembling the Heermanns Song Sparrow (Melospiza melodia heermanni). It was one of the smallest song sparrow subspecies and was characterized by a particularly gray back with dark streaks. Most song sparrows are browner in color with dark streaks. In general, a song sparrows breast and belly are white with dark streaking and a dark brown spot in the middle of the breast. It has a brown-capped head and a long, brown tail that is rounded on the end. The sparrows face is gray and streaked. The Santa Barbara song sparrows were distinguished from other song sparrows by a smaller, more slender bill, and a tail which was shorter than the wing. Habitat and Range The Santa Barbara Song Sparrow was known to exist only on 639-acre Santa Barbara Island (the smallest of the Channel Islands) in Los Angeles County, California. The sparrows natural habitat on the island was much like the habitat of other species of the song sparrow, which are generally abundant and adaptable on the mainland United States. Habitat components on the island that the sparrow relied on included: Thickets of shrubs like sagebrush, dense grasslands, and other scrubby vegetation for nesting and shelter (cover)Food resources such as giant coreopsis (Coreopsis gigantean, also called the tree sunflower), the Santa Barbara Island live-forever, shrubby buckwheat, and chicoryStanding or running fresh water or a consistent source of moisture from fog or dew Diet and Behavior In general, song sparrows are known to frequently forage on the ground and also in low vegetation where they are protected from predators by thickets and shrubs. Like other song sparrow species, the Santa Barbara Song Sparrow ate a variety of plant seeds and insects (including beetles, caterpillars, bees, ants and wasps, and flies). In spring, during the periods of nesting and rearing of young, insects increased in terms of the important components of the sparrows diet. The year-round diet of song sparrows in California is 21 percent insects and 79 percent plants; the song sparrow also eats crustaceans and mollusks on the coasts. Reproduction and Offspring Based on extant species of song sparrows on San Miguel, Santa Rosa, and Anacapa islands in the Channels, the Santa Barbara song sparrow built compact, open nests of twigs and other plant material, which were optionally lined with grass. The female laid three broods per season, each between two to six red-brown marked, pale green eggs. Incubation ranged from 12ââ¬â14 days and was tended to by the female. Both parents were involved in the feeding until the sparrows were fledged 9ââ¬â12 days later.à The birds were serially and simultaneously polygamous, and DNA studies showed that 15 percent or more of the young were sired outside the social pair. Extinction Process During the first half of the 20th century, sparrow nesting habitat (scrub vegetation) on Santa Barbara Island began disappearing as a result of clearing land for farming and from browsing by introduced goats, European rabbits, and New Zealand red rabbits. Unnatural predation also threatened sparrows during this time, after the introduction of domestic cats to the island. The sparrows natural predators included the American Kestrel (Falco sparverius), Common Raven (Corvus corax), and Loggerhead Shrike (Lanius ludovicianus). Even with these new challenges to its survival, the song sparrows maintained a viable population through the summer of 1958. Unfortunately, a large fire in 1959 destroyed most of the sparrows remaining habitat. The birds are thought to have been extirpated from the island during the 1960s because years of intensive surveys and monitoring throughout the 1990s did not reveal any resident song sparrows on the island. The U.S. Fish and Wildlife Service officially determined that the Santa Barbara Song Sparrow was extinct and removed it from the endangered species list on October 12, 1983, citing a loss of habitat and predation by feral cats. Sources Arcese, Peter et al. Song Sparrow Melospiza melodia. Birds of North America: Cornell Lab of Ornithology, January 1, 2002.à BirdLife International 2016. Melospiza melodia. The IUCN Red List of Threatened: e.T22721058A94696727, 2016. Santa Barbara song sparrow (Melospiza melodia . ECOS Environmental Conservation Online System, U.S. Fish and Wildlife Service.à graminea: Delisted due to ExtinctionVan Rossem, A. J. ââ¬Å"A Survey of the Song Sparrows of the Santa Barbara Islands.â⬠The Condor 26.6 (1924): 217ââ¬â220.Zink, Robert M., and Donna L. Dittmann. Gene Flow, Refugia, and Evolution of Geographic Variation in the Song Sparrow (Melospiza Melodia). Evolution 47.3 (1993): 717ââ¬â29.
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