Celebrating the 40th Anniversary of the Endangered Species Act: The Streaked Horned Lark Nominated for the Endangered Species List

Dave Stone, dns (at) efn.org

 

The Horned Lark is one of the most widespread bird species in North America. So how did it become a candidate for the endangered species list? The Horned Lark comprises 21 subspecies, including three or four that breed in Oregon. One subspecies, the Streaked Horned Lark, is found only in the southern Willamette Valley (where 900–1,300 individuals breed) and in isolated sites in Washington State and on the lower Columbia River. Its historical range extends from southern British Columbia through the Umpqua and Rogue River Valleys.

 

The Streaked Horned Lark occupies flat, wide-open spaces with sparse, low vegetation, no trees, and large expanses of bare ground. In the Willamette Valley, it finds this habitat in native prairies, plowed fields, intensively grazed pastures, gravel roads, Christmas tree farms, airports, and grass-seed fields.

These small songbirds eat seeds, seedlings of crop plants such as wheat or lettuce, and insects. Each year, females return to the same nest sites—shallow depressions in the ground lined with fine dead grass in the shade of rocks or clumps of vegetation. They typically lay four eggs. Eggs have been found as early as March and as late as mid-August, but they usually begin laying in early May. They incubate the eggs for 11 days, and the young can fly nine to 12 days after hatching.

The largest group of Streaked Horned Larks in Oregon breeds at the Corvallis Municipal Airport. The only known nest in Multnomah County is at the Portland International Airport.

 

The Streaked Horned Lark, like many endangered species, has declined over the past several decades in part because of habitat destruction. Developments in the historical range of the subspecies have replaced the sparsely vegetated, open fields it prefers with housing, commercial buildings, parking lots, and the like. 

Management of remaining suitable habitat has also contributed to the decline—for example, farmers plow fields during nesting season and grow tall grass that livestock prefer. 

Other threats include predation by skunks, raccoons, harriers, kestrels, dogs, and feral cats.

 

In October 2001 the US Fish and Wildlife Service (USFWS) gave the Streaked Horned Lark Candidate status; that is, it was put in line to be listed as a threatened species after higher priority species are protected. In October 2012 the USFWS determined that the Streaked Horned Lark might become threatened with extinction in the foreseeable future and upgraded its status to Proposed Threatened. This action was “part of the Service’s efforts to implement a court-approved work plan that resolves a series of lawsuits concerning the agency’s ESA Listing Program,” according to a USFWS news release.

 

The USFWS is also proposing a special rule that allows civil airport managers, farmers, and ranchers to “take” (harm or kill) Streaked Horned Larks without being held in violation of the listing.

 

USFWS: http://www.fws.gov/oregonfwo/Species/Data/StreakedHornedLark/

 

Oregon Public Broadcasting: http://www.opb.org/news/article/npr-can-this-rare-songbird-be-lured-away-from-risky-neighborhoods/

 

Portland Audubon: http://audubonportland.org/issues/species/streaked-horned-lark