California Horned Lark (Eremophila alpestris actia) Potential Occurrence: Nesting Unlikely to Occur




Дата канвертавання19.04.2016
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Aves (Birds): Passeriformes, Alaudidae

California Horned Lark (Eremophila alpestris actia)

Potential Occurrence: Nesting Unlikely to Occur



Status: (Nesting)

Federal: None

State: WL

Other: G5T3Q S3



S
Photo: Alan Vernon
pecies Description:
The Horned Lark is fairly slender with proportionally long wings, a short and stout bill, and square tail. Grey upperparts and white underparts, with a distinctive yellow and black mask and black collar. During summer, males have tiny black “horns” of plumage (Beason 1995; Sibley 2000).

Distribution: While the Horned Lark is widely distributed throughout North America and Europe, the California subspecies is found along the Coast Ranges from Humboldt County south, and in the central valley south to Baja California. This subspecies can also be found in the high Sierra Mountains during summer (Green 1990).

Life History & Threats: A year-round resident of most of California, the Horned Lark breeds from March through July, with the highest activity in May. Frequently there are two broods in one season, each with 2-5 eggs (Green 1990). This species is on the watch list because populations have declined 56% in the past 40 years (National Audubon Society 2010).

While the loss of agricultural fields to reforestation and development have contributed to the population declines in eastern North America (Buckelew and Hall 1994, Laughlin and Kibbe 1985), the factors responsible for their declines in other portions of North America are poorly understood. Habitat loss is a factor in southern California (Garrett and Dunn 1981), and may be involved in declines in other areas with rapidly expanding human populations. However, the varied temporal patterns shown by the declining populations may indicate that multiple factors are responsible for these survey-wide trends. (From Peter John, 1995)



Habitat & Habitat Associations:

General: Found on barren ground with short grass or scattered bushes (Sibley 2000). Often uses fallow agricultural fields (Green 1990)

Grassland, tundra, sandy regions, areas with scattered low shrubs, desert playas, grazed pastures, stubble fields, open cultivated areas, and rarely open areas in forest (AOU 1983). Nests in hollow on ground often next to grass tuft or clod of earth or manure. (From Hammerson 1995)



Nesting Habitat:

Nests in hollow on ground often next to grass tuft or clod of earth or manure. (From Hammerson



Conceptual Basis for GIS Model Development: We mapped potential habitat for this species as grasslands and agricultural fields. Areas of bare ground were also mapped, although bare ground in the study area is found exclusively within scoured riparian areas.

Potential Occurrence in the Galbreath Wildlands Preserve: Protection status for this species applies to nesting individuals.

Habitat: The quality of nesting habitat for Horned Larks is poor in the Preserve (Figure 83). Grasslands on the Preserve are not extensive and patchy in distribution. Since 2000, grasslands have not been grazed by cattle which would create the open grasslands and barren soil preferred by this species. Scoured mineral soils on stream terraces along the main stem of Rancheria Creek tend to support sparse grasslands and may be the best habitat for this species.

Nearest Occurrence:

Documented Occurrences in the Galbreath Wildlands Preserve: This species has not been documented on the Preserve. To our knowledge no surveys have been conducted.

Nearest Occurrence to the Galbreath Wildlands Preserve: This species has not been reported to occur in USGS quads adjacent to the Preserve.

Summary: We anticipate that nesting by this widespread permanent resident of northern California is “Unlikely to Occur” in the Preserve because quality nesting habitat is scarce.

References

Beason, Robert C. 1995. Horned Lark (Eremophila alpestris), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology . Accessed 2010 Jul 19.

Green M. 1990. Horned Lark. California Wildlife Habitat Relationships System Life History & Range Maps. . Accessed 2010 Jul 18.

Hammerson G. 1995 May 10. Ecology and Life History Edition. Comprehensive Species Report- Eremophila alpestris actia. NatureServe Explorer, Version 7.1. . Accessed 2010 Jul 19

National Audubon Society. 2010. Birds in Decline: Horned Lark. . Accessed 2010 Jul 18

Peter John B. 1995 Oct 11. Horned lark species account. Breeding Bird Survey. Version 94.0. Laurel, MD: National Biological Service Patuxent Environmental Science. . Accessed 2010 Jul 20.



Sibley DA. 2000. The Sibley Guide to Birds. New York: Alfred A Knopf. p 438.

Species Account Description: Kandis Gilmore & Emily Harvey


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