Volume 56, No. 4

THOMAS A. BENSON, KIMBALL L. GARRETT, MARQUETTE MUTCHLER (Author)

THE 49TH ANNUAL REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 2023 RECORDS

From its last report through 2023, the California Bird Records Committee reached decisions on 163 records involving 210 individuals of 56 species, endorsing 139 records of 185 individuals. Especially notable records detailed in this report include those of California’s second Common Greenshank (Tringa nebularia), third Gray Hawk (Buteo plagiatus), fourth Cory’s Shearwater (Calonectris borealis), an astonishing 72 Wedge-rumped Storm-Petrels (Hydrobates tethys), and the state’s first Red-headed Woodpecker (Melanerpes erythrocephalus) in 24 years.

RICHARD A. ERICKSON, BARY S. LESTER (Author)

REMEMBERING CALIFORNIA’S WINTERING DUSKY CANADA GEESE (BRANTA CANADENSIS OCCIDENTALIS)

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The Dusky Canada Goose (Branta canadensis occidentalis) once wintered regularly by the hundreds on the north coast of California, yet this fact has now vanished from much of the literature on the Canada Goose. In the 1930s James Moffitt found the subspecies was regular at two sites in Del Norte and Humboldt counties, but by the mid-1980s its numbers were much reduced and only occasional individuals were found thereafter. The retraction of the Dusky Canada Goose from the southern limit of its winter range parallels a rangewide population decline as well as surges in numbers of the recovering Aleutian Cackling Goose (B. hutchinsii leucopareia) and the proliferating Western Canada Goose (B. c. moffitti), possibly competitors.

CAMERON TESCHER, JASMINE AGUILAR, JESSICA BAGGOTT, STEFANIE BÖTTCHER, JAY CHEN, FRANCIS L. FABBRO, ASHLEIGH K. McNEIL, LAURA MORRIS, ZANE PICKUS, ALON S. ROBBINS, JUSTIN SALDANA, FINNIAN A. VELISARIS, ANGELA YANG, ROBERT E. FURROW (Author)

NOCTURNAL FLIGHT CALLS DURING SPRING MIGRATION IN NORTHERN CALIFORNIA

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Monitoring of nocturnal flight calls to study bird migration is widely used in the eastern and central United States, but its application in the West has been limited. To assess the potential for such monitoring in northern California and to compare patterns of migration between sites in California’s Central Valley and nearby locations in the Coast Ranges, we analyzed data on flight calls recorded in April and May 2022 by five automated units. We counted all recorded songbird calls and identified four common migratory western songbirds with distinctive flight calls as our focal species: the Swainson’s Thrush (Catharus ustulatus), Wilson’s Warbler (Cardellina pusilla), Yellow Warbler (Setophaga petechia), and Lazuli Bunting (Passerina amoena). We detected songbird calls at a higher rate at the sites in the Central Valley than at those in the Coast Ranges, found differences by site in the nightly frequency of calls from three of the four focal species, and noted more flight calls from migratory species other than songbirds at the Central Valley sites. BirdCast’s radar estimates of nightly average birds in flight strongly predicted the number of songbird nocturnal flight calls we detected each night.

ROBERT L. SCHER (Author)

SECOND PREBASIC MOLT OF A RING-BILLED GULL AT ANCHORAGE, ALASKA

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The extended stay of a Ring-billed Gull (Larus delawarensis) at Anchorage, Alaska, where the species is casual, provided the opportunity for observation of the second prebasic molt of a single individual. That molt was at an early stage when the bird was first found on 9 July 2024 and was completed by mid-October, in agreement with the schedule reported from the Ring-billed Gull’s normal range. Growth of the outermost primary was slower than that of the others, perhaps related to that feather’s greater mass and variable density along its length, or because the focus of the bird’s biophysical systems had begun to shift from molt to preparation for migration and winter.

HIRAM RAFAEL MORENO-HIGAREDA, ISABEL RAYMUNDO-GONZÁLEZ, ENRIQUE D. ZAMORA-HERNÁNDEZ, JOSÉ ANTONIO MALDONADO CEJA, JUSTYN T. STAHL (Author)

The Swallow-tailed Kite in Baja California, Mexico

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From 19 April through August 2025, a Swallow-tailed Kite, possibly a single individual, was seen at various locations straddling the Mexico/USA border, from El Rosario, Baja California, northwest 585 km to western Ventura County, California. Photographed at Ensenada, Baja California, as well as at various locations north of the border, it represents a first photo-documented record of the Swallow-tailed Kite for the peninsula. After spring wanderings both north and south, it summered at Machado Lake in Harbor City, Los Angeles.

MASON W. MARON (Author)

BEHAVIORAL OBSERVATIONS OF LESSER GOLDFINCHES IN PULLMAN, WASHINGTON

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In Pullman, Washington, to which the Lesser Goldfinch (Spinus psaltria) had spread by the late 1990s, regular observations of the species over four years revealed several notable insights. Seeds of the nonnative Tansy (Tanacetum vulgare) are a major and apparently preferred constituent of the bird’s diet at Pullman. There, as elsewhere in its range, the Lesser Goldfinch imitates other birds; within an interval of 30 seconds, one singing male imitated the sounds of 10 species, including the European Starling (Sturnus vulgaris), previously unreported as one of the goldfinch’s models.

DOMINIK MOSUR, MARTIN FREELAND (Author)

FIRST RECORD OF THE SLATE-THROATED REDSTART FOR CALIFORNIA

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We detail the occurrence of a Slate-throated Redstart (Myioborus miniatus) in an urban park in San Francisco from 29 July to 16 September 2024, establishing the first record for California and the northernmost for the species. The bird showed characters of the northern subspecies, M. m. miniatus. It may have reached this site as a late spring overshoot or possibly via a molt migration. This represents the 47th species of wood-warbler (Parulidae) recorded in California, and—remarkably—the 46th for San Francisco County.