Executive Summary
We surveyed for Least Bell’s Vireos (Vireo bellii pusillus; vireo) and Southwestern Willow Flycatchers (Empidonax traillii extimus; flycatcher) at the Mojave River Dam study area near Hesperia, California, in 2021. Four vireo surveys were conducted between April 16 and July 16, 2021, and three flycatcher surveys were conducted between May 27 and July 16, 2021.
We detected four territorial male vireos, including two that were paired and two with undetermined breeding status. No juveniles were observed during surveys. Vireo territories were found in three habitat types: (1) riparian scrub, (2) willow-cottonwood, and (3) willow-sycamore, with willow-cottonwood being the most commonly recorded habitat type. Red or arroyo willow (Salix laevigata or lasiolepis) was the dominant plant species in most vireo territories.
No territorial or transient flycatchers were observed.
Citation Information
| Publication Year | 2022 |
|---|---|
| Title | Distribution and abundance of Least Bell’s Vireos (Vireo bellii pusillus) and Southwestern Willow Flycatchers (Empidonax traillii extimus) at the Mojave River Dam, San Bernardino County, California—2021 Data summary |
| DOI | 10.3133/dr1149 |
| Authors | Scarlett L. Howell, Barbara E. Kus |
| Publication Type | Report |
| Publication Subtype | USGS Numbered Series |
| Series Title | Data Report |
| Series Number | 1149 |
| Index ID | dr1149 |
| Record Source | USGS Publications Warehouse |
| USGS Organization | Western Ecological Research Center |