Distribution, Abundance, and Breeding Activities of the Southwestern Willow Flycatcher at Marine Corps Base Camp Pendleton, California—2022 Annual Report
Least Bell's Vireos and Southwestern Willow Flycatchers at the San Luis Rey Flood Risk Management Project Area in San Diego County, California: Breeding Activities and Habitat Use—2022 Annual Report
Distribution, Abundance, and Breeding Activities of Southwestern Willow Flycatchers (Empidonax traillii extimus) at Select Locations on the San Luis Rey River, San Diego County, California—2024 Data Summary
Distribution and Abundance of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the Upper San Luis Rey River, San Diego County, California—2023 Data Summary
Evidence of honest signalling in a suboscine bird: Southwestern willow flycatcher song frequency is positively related to apparent reproductive success
Applying Satellite-based Habitat Models to Inform Riparian Habitat Restoration and Management Actions for Two Listed Riparian Species, the Southwestern Willow Flycatcher and the Yellow-billed Cuckoo
James Hatten1, Jennifer Holmes2, and Matthew Johnson3*
This chapter from The Codex of the Endangered Species Act, Volume II: The Next Fifty Years describes how genetic information is used to inform decision-making for the Endangered Species Act. In one section of this chapter (page 4 of the PDF, page 162 of the book), the use of genomics to differentiate between subspecies of willow flycatcher (Empidonax traillii) is described.
This article describes how researchers discovered that southwestern willow flycatchers in southern California have evolved in response to climate change. Southwestern willow flycatcher (SWFL) populations are threatened by climate change and habitat loss. By sequencing DNA from historical SWFL samples and comparing these to modern samples, researchers determined that modern SWFL were more likely to have beneficial genes that help them cope with changing climate.
A look at the evolutionary response to climate change in the endangered southwestern willow flycatcher (Empidonax traillii extimus) using whole-genome comparisons between historic and modern specimens from California. While introgression led genomes of neighboring E. traillii extimus populations (California and Arizona) to become more similar, the specific loci linked to climate shifted in a way consistent with climate adaptation rather than becoming more similar to those of neighboring populations.
From the abstract:
An understanding of trait-environment relationships is particularly important in the case of invasive species which may alter abiotic conditions and available resources. This study is the first to measure the functional response of riparian plant communities to biocontrol of an invasive species.