[Posted by Chuck Almdale]

The recording of this program from 7 Nov 2023 is now available on-line

Gray Vireo (photo supplied by Dr. Phil Unitt)

The program starts 8 seconds in. At 9:20 there is a glitch, corrected at 11:20.

Gray Vireos in Baja with Dr. Phil Unitt

Gray Vireo on nest (photo supplied by Dr. Phil Unitt)

Most of the breeding range of the Gray Vireo lies within the southwestern United States, where the population is sparse, patchy, and declining. But the species also breeds in Baja California, where its status had not been assessed until 2021 and 2022 when we surveyed four mountain ranges where it was known or might be expected. In the sierras Juárez and Sierra San Pedro Mártir we found the Gray Vireo strikingly more common than just across the border in Upper California. Most territories were treeless chaparral dominated by chamise and redshank. Isolated stands of chaparral grow south of the Gray Vireo’s previously reported breeding range, on the Sierra La Asamblea, but our reconnaissance there revealed no Gray Vireos. In the Sierra San Francisco in the center of the peninsula, the Gray Vireo is a winter visitor only. Although Baja California represents only a small part of the Gray Vireo’s breeding range spatially, it contributes disproportionately to the species’ population and therefore conservation.

Gray Vireo eggs in nest (photo supplied by Dr. Phil Unitt)

Dr. Philip Unitt, native of San Diego County, has spent his entire career at San Diego Museum of Natural History where he is the Dennis and Carol Wilson Endowed Chair of Ornithology and Curator of Birds and Mammals.  He studies the distribution, ecology, history, identification, and conservation of California birds. He is a specialist in subspecies identification, distribution, and history of distributional change of California birds. He has led extensive survey projects, organizing hundreds of volunteers; analyzing very large data sets; and has prepared more than 4,000 bird specimens for the museum reference collections.  He is the lead author of the San Diego Bird Atlas and a major contributor to Birds of San Diego County and the coauthor of the Birds of the Salton Sea. Dr. Unitt is also the editor of Western Birds, the regional journal of ornithology for western North America.

Gray Vireo habitat (photo supplied by Dr. Phil Unitt)