The WFVZ currently conducts bird species research in three primary study areas in California:  the Santa Clara River, northern Channel Islands and Channel Islands National Park, and the Santa Monica Mountains National Recreation Area and surrounding open spaces. We have also conducted work in Guatemala and are continuing to support ongoing conservation and research efforts there. Since 2008, Dr. Linnea Hall, executive director of the WFVZ and an avian conservation biologist with 30 years of experience, has been creating a strong research and monitoring program for birds in the region.

Continuing reading to learn more about our organization’s main projects.

scriver1  scriver3

Santa Clara River Research

The Santa Clara River watershed, in Ventura and Los Angeles counties, drains a biologically rich region and contains a particularly strong representation of the biodiversity in the South and Central Coast Bioregions. It is one of the few major river systems in California that retains much of its natural hydrology. The river provides the ecosystem functions necessary to support many federally listed species and State Species of Special Concern, including three endangered bird species; Least Bells’ Vireo (Vireo bellii pusillus), Southwestern Willow Flycatcher (Empidonax traillii extimus), and Western Yellow-billed Cuckoo (Coccyzus americanus occidentalis). The river basin also sustains some of the most valuable agricultural resources in the world. It provides water resources for surrounding urban populations, and provides diverse outdoor recreational opportunities.

Our work on the river started in 2010 with annual monitoring of bird species densities and richness at one site (the Hedrick Ranch Nature Area, managed by the Friends of the Santa Clara River [FSCR]). We now have a decade of data showing trends on the property! Since 2010, we have expanded our projects to include regular annual monitoring of endangered Least Bell’s Vireo nests at multiple locations, including on Nature Conservancy (TNC) properties on the river; modeling of long-term LBVI population viability for the USFWS; evaluations of Brown-headed Cowbird (Molothrus ater) parasitism; surveys and habitat modeling for Yellow-billed Cuckoo and Southwestern Willow Flycatcher; and regular population estimation of all riparian breeding birds on 17 TNC properties on the river. A particularly satisfying part of our work most recently (since 2016) has been to monitor nesting and other demographic responses of birds to riparian woodland restoration on several properties on the river.

LBVI banding   Yellow-billed Cuckoo
Banding a Least Bell’s Vireo (Vireo bellii pusillus) at HRNA and Yellow-billed Cuckoo (Coccyzus americanus) spotted on SC River. (©Adam Searcy)

Our partners in this work include many colleagues and organizations. Resource management partners include the California Department of Fish and Wildlife, U.S. Fish and Wildlife Service, The Nature Conservancy, Stillwater Sciences, Friends of the Santa Clara River, U.C. Santa Barbara (UCSB), Santa Clara River Conservancy, Channel Islands Restoration, and the Conejo Valley and Ventura Audubon Society chapters. Specific colleagues who have been instrumental in our work are René Corado and Mimi Damwyk of the WFVZ, Dr. Bruce Orr of Stillwater Sciences (and on the Board of the WFVZ), Dr. Jim Hatten of the USGS in Oregon, A. Searcy of Creosote Biological, D. Orr of UCSB, A. Plesetz of Flora and Fauna, D. Wappler, D. Kamada, M. Bellini of Sentinel Science, Dr A. Lambert at UCSB, biologists at the USFWS office in Ventura (C. Dellith, J. Marek, E. Morrisette), California Department of Wildlife Biologists (especially D. Blankenship), S. Hedrick at the HRNA and on the Board of the FSCR, staff of TNC (L. Riege, K. Selm, P. Dixon), Dr. B. Kus at the US Geological Survey (USGS) in San Diego, and D. Klabunde (who has volunteered his time making passive cuckoo detection devices for our work).

For additional information, please see these references for our work on the Santa Clara River:

1. Hall, L.S., B.K. Orr, J.R. Hatten, A. Lambert, and T. Dudley.  2020.  Final Report:  Southwestern Willow Flycatcher (Empidonax traillii extimus) and western Yellow-billed Cuckoo (Coccyzus americanus occidentalis) surveys and habitat availability modeling on the Santa Clara River, California, 26 March 2020.  Submitted to the California Department of Fish and Wildlife and the U.S. Fish and Wildlife Service.

2. STANTON, J. C., J. MAREK, L. S. HALL, B. E. KUS, A. ALVARADO, B. K. ORR, E. MORRISSETTE, L. RIEGE, and W. E. THOGMARTIN. 2019.  Recovery planning in a dynamic system: integrating uncertainty into a decision support tool for an endangered songbird. Ecology and Society 24(4):11.

3. Peer, B.D., B.E. Kus, M.J. Whitfield, L.S. Hall, and S.I. Rothstein. 2020. Management of the brown-headed cowbird: implications for endangered species and agricultural damage mitigation. Human–Wildlife Interactions 14(3):Early Online, Winter 2020.

Read more about Santa Clara River conservation here

Read more about Yellow-billed Cuckoo here

Northern Channel Islands Research

Since 2008, the WFVZ has assisted the National Park Service (NPS) at Channel Islands National Park with bird monitoring on the islands.  Starting in 2008, the NPS Learning Resource Center brought Linnea Hall in to help design, implement, and conduct a population estimation project for the Northern Island Loggerhead Shrike (Lanius ludovicianus anthonyi), and this project was two-year effort on Santa Cruz and Santa Rosa islands that involved about 60 volunteer ornithologists, several agency partners, and hundreds of hours of work to organize and execute.  Specific people who really helped the WFVZ make this project happen were: L. Dye, Ecologist and Data Archivist for NPS Channel Islands (retired); Dr. T. Stanley at the USGS in Colorado (retired); S. Teel, former head of the Learning Resource Center for the NPS; and the tough group of biologists who combed the hills and plateaus of the islands looking for this species!

Starting in 2015, the WFVZ also began participating in annual breeding bird monitoring on five northern islands (Anacapa, Santa Barbara, Santa Cruz, San Miguel, and Santa Rosa). In 2016, the WFVZ took over the execution and reporting for this monitoring for the NPS. The data from this project form the basis of many Park decisions about the management of the islands, and they are part of a program that extends back to when it was started in 1993. Linnea Hall and an amazing team of NPS staff and biologists, as well as private individuals, who are adept at identifying birds by sight and sound, conduct point counts between March and June annually on the islands. If you are a great point counter, and have abilities to hike and navigate off-trail, please contact Linnea to participate in this project ( Since 2016, people who have been invaluable to the WFVZ in this effort include: Park staff (L. Dye [retired], T. Coonan, L. Lee, L. Shaskey, A. Little, S. Baker, J. Howard), C. Villasenor, P. Larramendy, J. N. Todd, and A. Seary, and Dr. Lyndal Laughrin of the UC Reserve on Santa Cruz Island.

For additional information, please see these references for our work on the Channel Islands:

Coonan, T. J., and L. C. Dye. 2016. Trends in landbird abundance at Channel Islands National Park, 1993-2015. Natural Resource Report NPS/MEDN/NRR—2016/1335. National Park Service, Fort Collins, Colorado.

STANLEY, T. R., S. TEEL, L. S. HALL, L. C. DYE, and L. L. LAUGHRIN.  2012.  Estimating the population size of island loggerhead shrikes on Santa Rosa and Santa Cruz Islands, USA.  Wildlife Society Bulletin 36(1):61–69.

Santa Monica Mountains National Recreation Area and Conejo Open Space Conservation Area Research

Starting in 2008, the WFVZ began partnering with the Santa Monica Mountains National Recreation Area (SMMNRA) to keep track of birds in the mountains. The initial project was on Grasshopper Sparrows (Ammodramus savannarum) breeding in the SMMNRA, for which Linnea Hall brought together a team of amateur and professional expert-level volunteer bird observers to determine the number of active breeding territories for the species. This one-year project helped form the basis of Dr. Hall’s subsequent efforts to determine the population size of shrikes on two Channel Islands (above), and additional monitoring. In 2016, Dr. Hall collaborated with the SMMNRA staff to establish random point count stations throughout the Santa Monica Mountains and began conducting annual counts of breeding birds that year. In 2019, points were also established on adjacent Conejo Open Space Conservation Area (COSCA) land. People who have been extremely helpful to the WFVZ in getting these projects implemented are: NPS staff (Dr. K. Delany, M. Mendelsohn, S. Leary, J. Tiszler, and J. Algiers), COSCA staff (A. Huber), WFVZ staff (S. Mateos, M. Romero), and volunteers (D. Kelly, R. Ammerding, D. Torfeh, T. Schmitt, B. Henderson, D. Klabunde).

The current Community Science counting project relies on volunteers to conduct the bird monitoring and provides training in the methodology. It does require a two season commitment to the project. If you are already good at identifying birds by sight and sound (or want to get better at identifying them by sound), and are able to hike on canyon trails and roads, then this is the project for you! The NPS SMMNRA staff, and the COSCA staff, rely on these bird data for their management decisions in these important natural areas. Contact Dr. Hall ( for additional information!

For additional publications on field projects conducted by the WFVZ, please see:

COOPER, D. S., L. S. HALL, and A. J. SEARCY.  2014.  A population census of the cactus wren in Ventura County, California.  Western Birds 45:43-56.