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 31 July 2017. Twenty-one transient Willow Flycatchers of unknown subspecies were observed during Base-wide surveys. Transients occurred on 5 of the 16 drainages surveyed in 2017. No Willow Flycatchers were detected at Aliso Creek, Cockleburr Canyon, Fallbrook Creek, French Creek, Horno Canyon, Piedra de Lumbre Canyon, Pilgrim Creek, Roblar Creek, San Mateo Creek, San Onofre Creek, or Windmill Canyon. Transients occurred in a range of habitat types including mixed willow (Salix spp.) riparian, riparian scrub, willow-sycamore (Platanus racemosa), and sycamore-oak (Quercus agrifolia) dominated riparian vegetation. Exotic vegetation including black mustard (Brassica nigra) and poison hemlock (Conium maculatum) was present in the majority of flycatcher locations.
Number of pages: 81
Authors: Howell, Scarlett L.; Kus, Barbara;
Year: 2017
Purpose: The purpose of this study was to document the status of Southwestern Willow Flycatchers at Marine Corps Base Camp Pendleton (MCBCP or “Base”) 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. In addition, we report the ongoing effects of a series of major wildfire events that occurred in 2014 on Willow Flycatchers and their habitat. These data, when combined with data from other years, will inform natural resource managers about the status of this endangered species at Marine Corps Base 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 parasitism; habitat loss;
Species: Southwestern willow flycatcher
Vegetation communities: riparian forest & scrub
Threats: Parasitism/disease