Type: report
Article abstract: Surveys for the endangered Least Bell's Vireo (Vireo bellii pusillus) were conducted at Marine Corps Base Camp Pendleton (MCBCP or Base), California, between 31 March and 14 July 2014. Drainages containing riparian habitat suitable for vireos were surveyed two to four times. Six hundred and thirty-four male vireos and 37 transient vireos were detected. An additional 83 male vireos were initially detected within the perimeter of a wildfire that burned vireo habitat mid-May 2014 and perished or were displaced by the wildfire. Territorial vireos were detected on 20 out of the 23 drainages/sites surveyed. Ninety-two percent of all vireo territories occurred on the six most populated drainages, with the Santa Margarita River containing 65% of all territories on Base. Sixty-nine percent of male vireos were confirmed as paired.
Number of pages: 133
Authors: Lynn, Suellen; Kus, Barbara; Allen, Lisa;
Year: 2014
Purpose: The purpose of this study was to document the status of Least Bell's Vireo at Marine Corps Base Camp Pendleton in San Diego County, California. Specifically, our goals were to (1) determine the size and composition of the vireo population at the Base, (2) characterize habitat used by vireos, (3) band a subset of vireos to facilitate the estimation of vireo survivorship and movement, (4) assess the short-term effects of giant reed removal on vireo fecundity, nest success, and productivity by intensively monitoring vireos within established nest monitoring sites that had recently undergone giant reed removal (2008) and at reference sites in which giant reed had been removed 15-17 years earlier, between 1997 and 1999, (5) assess the effects of the wildfires on vireos by measuring vireo fecundity, nest success, and productivity by intensively monitoring vireos within newly established nest monitoring sites that burned in October 2013 (sections of the Santa Margarita River and De Luz Creek) compared to the reference sites used to achieve goal 4, and (6) document the vegetation structure and plant composition during the first breeding season post-fire in the sites that burned in October 2013 and the subsequent recovery of the vegetation at these sites. When combined with data from other years, these data will inform natural resource managers about the status of this endangered species at MCBCP, 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;
Prepared by: U.S. Geological Survey, Western Ecological Research Center;
Keywords: endangered species; least Bell's Vireo; Marine Corps Base Camp Pendleton;
Species: Least Bell's vireo
Vegetation communities: riparian forest & scrub
Threats: Parasitism/disease