Type: report
Article abstract: Surveys for the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) were conducted at Marine Corps Base Camp Pendleton, California, between 16 May and 28 July 2016. One hundred and seven transient Willow Flycatchers of unknown subspecies were observed during Base-wide surveys. Transients occurred on 12 of the 16 drainages surveyed in 2016. No Willow Flycatchers were detected at Cristianitos Creek, Horno Canyon, Roblar Creek, or San Onofre Creek. Transients occurred in a range of habitat types including mixed willow (Salix spp.) riparian, riparian scrub, and willow-sycamore (Platanus racemosa) dominated riparian vegetation. Exotic vegetation including poison hemlock (Conium maculatum) and black mustard (Brassica nigra) was present in the majority of flycatcher locations.
Number of pages: 95
Authors: Howell, Scarlett L.; Kus, Barbara;
Year: 2016
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 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