Type: report
Article abstract: Surveys for the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) were conducted at Marine Corps Base Camp Pendleton, California, between 15 May and 28 July 2009. Thirty-five transient flycatchers of unknown sub-species were observed during Base-wide surveys. Transients occurred on 10 of the 16 drainages surveyed in 2009. No Willow Flycatchers were detected at Aliso Creek, Cristianitos Creek, Fallbrook Creek, Horno Canyon, Piedra de Lumbre Canyon, or Roblar Creek. Transients occurred in a range of habitat types including mixed willow (Salix spp.) riparian, willow-sycamore (Platanus racemosa) dominated riparian, oak (Quercus sp.)-sycamore dominated riparian, riparian scrub, and upland scrub. The distance from transient locations to the nearest surface water averaged 451 ± 593 m (std, n = 35).
Number of pages: 58
Authors: Howell, Scarlett L.; Kus, Barbara;
Year: 2009
Purpose: The purpose of this study was to document the status of Southwestern Willow Flycatchers at Marine Corps Base Camp Pendleton in San Diego County, California. Specifically, our goals were to (1) determine the size and composition of the Willow Flycatcher population at the Base, (2) document survivorship and movement of resident flycatchers, (3) document nesting activities, and (4) characterize habitat used by flycatchers. These data, when combined with data from other years, will inform natural resource managers about the status of this endangered species at Camp Pendleton, and guide modification of land use and management practices as appropriate to ensure the species’ continued existence.
Prepared for: Assistant Chief of Staff, Environmental Security U.S. Marine Corps Base Camp Pendleton;
Keywords: cowbird; cowbird parasitism; habitat loss;
Species: Southwestern willow flycatcher
Vegetation communities: riparian forest & scrub
Threats: Parasitism/disease