The streaked horned lark is a coastal subspecies only found in southwest Washington and western Oregon, with a range-wide population estimated at 1,170 to 1,610. It is an uncommon breeder on airport grasslands and remnant prairies and beaches of western Washington and Oregon. Primary concerns are loss and degradation of habitat and human-related disturbance and mortality (example: mowing of grass) at breeding sites. is
Description and Range
The streaked horned lark is 7 inches in length. These birds are brown above and pale buff-colored below. The head sports two black feathered “horns.” The face is pale yellow and there is a black band beneath the eye, from beak to cheek as well as on the upper breast.
Ecology and life history
In Washington, streaked horned larks are found on prairie and grassland south of Puget Sound, coastal beaches, and islands and sparsely vegetated shoreline sites on the lower Columbia River. Streaked horned larks are also found on agricultural fields and drying seasonal wetlands in Oregon. Their habitat consists of large expanses of bare or sparsely vegetated land, including fields, prairies, upper beaches, airports, and similar areas with low/sparse grassy vegetation.
Streaked horned larks forage on the ground in bare fields among short vegetation. They eat seeds and grass but feed their young insects.
They may rear two to three broods per season.
They are known to overwinter in Oregon and on some of the lower Columbia River sites.
The streaked horned lark is an uncommon breeder on airport grasslands and remnant prairies and beaches of western Washington and Oregon. It is considered eliminated in British Columbia.
The streaked horned lark is currently known to breed at up to 17 locations in Washington; 8 in the southern Puget Sound region; 6 sites on the outer coast; and 4 on islands and shore sites along the lower Columbia River. Oregon breeding areas include up to 11 along the lower Columbia, as well as airports and agricultural fields in the Willamette Valley.
Based on detections of singing males during standardized surveys, approximately 147 pairs were present at known Washington sites in 2015. Density trends from standardized transect data for 2010 to 2014 suggested that the populations at most sites were stable; however, the range-wide population is estimated at 1,170 to 1,610 individuals, including fewer than 150 pairs in Washington.
For a map reflecting this species' conservation status and other species' information, check out NatureServe Explorer and the International Union for Conservation of Nature Redlist.
Sensitivity to climate change
Streaked horned larks likely exhibit physiological sensitivity to warmer temperatures; they have been documented to alter behavior during warm periods (e.g., forage in shade, use wings to shade nests) and heat events have interrupted breeding season in other states. Streaked horned larks prefer open habitats with ample bare ground and very sparse, low stature vegetation. Populations in grassland areas may benefit from increasing fire frequencies that reduce vegetative cover and shrub/tree encroachment. Populations nesting on the banks of the Columbia River may be vulnerable to shifting flow regimes and flood peaks. Populations in beach/dune habitats along the Washington coast are vulnerable to changing sediment accretion and erosion patterns, which can change in response to hydrological shifts, current changes, changing precipitation patterns, and human management practices.
Exposure to climate change
- Increased temperatures
- Altered hydrology
- Altered sediment accretion and erosion patterns (coastal)
Conservation Threats and Actions Needed
- Fish and wildlife habitat loss or degradation
- Threat: Loss of prairie/grassland habitat.
- Action: Acquire or restore nesting habitat.
- Threat: Inbreeding/declining genetic health.
- Action: Translocation from Oregon for genetic augmentation.
- Resource information collection needs.
- Threat: Information needed on distribution, abundance, and status.
- Action: Occupancy surveys/counts at known and potential sites; compile, analyze data.
- Management decision needs
- Threat: Disturbance/mortalities on Columbia River sites from dredged material deposition.
- Action: Promote development of a management plan for dredged material at Columbia River sites.
- Overharvesting of biological resources
- Threat: Mortalities from collisions with aircraft on airfields.
- Action: Create/restore nesting habitat away from runways.
See the Climate vulnerability section above for information about the threats posed by climate change to this species. In addition, toxic substances may present a hazard to streaked horned larks; these include zinc phosphide, used to control rodents, and seeds treated with pesticides to control pests and fungus.
The subspecies is the focus of concerted conservation efforts with several key partners involved, including Joint Base Lewis-McChord, Center for Natural Lands Management, U.S. Army Corps of Engineers, civilian airports (e.g., Corvallis, Olympia, and Shelton), Oregon State University, U.S. Fish and Wildlife Service, American Bird Conservancy, Port of Portland, and The Evergreen State College. Conservation actions include protecting nests and fledglings at nesting areas, restoring habitat, genetic augmentation of an at-risk population, and experiments to attract larks to new locations.
Joint Base Lewis-McChord has collaborated with Center for Natural Lands Management to monitor lark nests to help minimize impacts of mowing and training activities on nesting, and lark reproductive success improved in 2014 and 2015; no nests were lost to human-related causes in 2015. The Army Corps of Engineers recently committed to maintain and increase lark habitat at Columbia River dredged material deposition sites. These actions have improved the outlook for lark recovery.
- Washington State Periodic Status Review for the Streaked Horned Lark (2016)
- Washington State Status Report for the Mazama Pocket Gopher, Streaked Horned Lark, and Taylor's Checkerspot (2005)
- Range-wide Streaked Horned Lark (Eremophila alpestris strigata) Assessment and Preliminary Conservation Strategy (2005)