Western Birds Journal

Volume 51, No. 2

Published April 1, 2020

Issue description

Volume 51, number 2 of Western Birds, published 2020

Articles

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    BRYCE W. ROBINSON, JACK J. WITHROW, RACHEL M. RICHARDSON, STEVEN M. RICHARDSON, ROBERT E. GILL, Jr., ANDREW S. JOHNSON, IRBY J. LOVETTE, JAMES A. JOHNSON, ANTHONY R. DEGANGE, MARC D. ROMANO (Author)

    FURTHER INFORMATION ON THE AVIFAUNA OF ST. MATTHEW AND HALL ISLANDS, BERING SEA, ALASKA

     In June and July 2018 and July 2019 we surveyed birds on St. Matthew and Hall islands, isolated in the central Bering Sea. Our surveys were focused on the McKay’s Bunting (Plectrophenax hyperboreus), Rock Sandpiper (Calidris ptilocnemis ptilocnemis), and Pelagic Cormorant (Phalacrocorax pelagicus) but encompassed all birds and yielded 13 species and four subspecies new to the islands’ avifaunal list, and new details and documentation of breeding for eight species. Especially notable discoveries include a mixed pair of Bewick’s (Cygnus columbianus bewickii) and Whistling (C. c. columbianus) Swans, a mixed pair of the Glaucous-winged (Larus glaucescens) and an Asian subspecies of the Herring Gull (L. argentatus vegae), and discovery of a colony of ~100 pairs of the Red-legged Kittiwake (Rissa brevirostris). Also, contrary to many previous expeditions, we found the Gray-crowned Rosy-Finch (Leucosticte tephrocotis umbrina) to be common and conclude that it may be resident.

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    DANIEL M. TAYLOR (Author)

    WINTER POPULATIONS OF WAXWINGS IN IDAHO

     i explored the winter distributions of the Cedar Waxwing (Bombycilla cedrorum) and Bohemian Waxwing (B. garrulus) in idaho by means of the results of Christmas Bird Counts from 1980 to 2016. in northern idaho the Bohemian was signifiantly more abundant, but in southern idaho its numbers declined signifiantly, as the frequency of large-scale irruptions dropped. annual variability in the Bohemian Waxwing was signifiantly greater than that of the Cedar in both regions of idaho. in neither species was variation in the two regions correlated. in southern idaho numbers of the Cedar Waxwing decreased with elevation while that of the Bohemian increased. Both species were more numerous in count circles
    that include mountain slopes than in those consisting of valley flors only, a preference stronger in the Cedar Waxwing than in the Bohemian. a positive correlation between the Cedar Waxwing’s abundance and the size of the human population in southern idaho suggests an effct of ornamental plants. in neither species in neither region did i fid a correlation between the birds’ abundance and mean temperature in november or December. limited data on the annual variability in the production of wild fruit in northern idaho showed no signifiant correlations with waxwing numbers in that region.

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    CAMERON D. ECKERT, RICHARD R. GORDON (Author)

    HIRUNDO RUSTICA RUSTICA AT HERSCHEL ISLAND–QIKIQTARUK, YUKON— A BARN SWALLOW SUBSPECIES NEW TO CANADA

     At least three of the 19 Barn Swallows recorded on Herschel Is- land–Qikiqtaruk, along the Arctic coast of the Yukon Territory, represent the white- bellied Old World subspecies Hirundo rustica rustica. Th birds were photographed on 3 July 2010, 24 July 2015, and 19–20 June 2019. Thse fist Canadian records are complemented by fie from northern Alaska, west to Utqiaġvik (Barrow). Ths subspecies breeds in Europe, Africa, and northwestern Asia, east to the Yenisei River. Th lack of Alaska records of H. r. rustica to the west of Utqiaġvik and of Canadian records east of Qikiqtaruk suggest that these vagrants reached the New World not by orienting or driftng at the wrong angle but by overshooting their normal spring migration path, following a nearly polar great-circle route.

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    JULES EVENS (Author)

    TEMPORAL RESPONSE OF CALIFORNIA BLACK RAILS TO TIDAL WETLAND RESTORATION

     From the mid-1800s into the 1960s, many tidal wetlands along the coast of California were isolated from tidal inflence and converted to farmland. since 1976, to restore ecological function and hydrological integrity, tidal inflence has been restored to some of these wetlands. My collaborators and I monitored three sites—one on the north edge of san Pablo Bay, one on the west side of san Francisco Bay, and one at the south end oftomales Bay—to document occupancy by the California Black Rail (Laterallus jamaicensis coturniculus), a cryptic marsh bird with an extremely narrow habitat niche in emergent tidal wetlands and considered an indicator of tidal-marsh health and restoration success. A source of prospective
    colonists had persisted adjacent to all three sites. Black Rails occupied each site within three to ten years, demonstrating the value of these restorations.

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    NATHAN PIEPLOW, ANDREW SPENCER (Author)

    VOCAL DIFFERENCES AMONG THE BARRED, CINEREOUS, AND FULVOUS OWLS

     Th Cinereous owl (Strix sartorii), a Mexican pine forest endemic, has long been considered a subspecies of the Barred owl (S. varia). in this study, we provide the fist description and analysis of its vocalizations, which diffr markedly from those of the Barred owl and support the recognition of the Cinereous owl as a full species. its rhythmic song consists of seven primary notes and three secondary notes, whereas the analogous song of the Barred owl consists of six primary notes and two secondary notes, arranged in a diffrent pattern. Th rhythmic song of the closely related Fulvous owl (S. fulvescens) has only fie or six primary notes, versus seven in that of the Cinereous owl. Th Cinereous owl’s song is much lower in
    pitch than the Fulvous owl’s. Unlike the Fulvous owl but like the Barred owl, the Cinereous owl also has a distinctive and frequently deployed series song.

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    PETER PYLE (Author)

    MOLT, AGE, AND IDENTIFICATION OF THE MASKED AND NAZCA BOOBIES IN CALIFORNIA

     I examined photographs compiled by the California Bird Records Committee to assess bill-color and plumage-color changes with molt of the primaries in Masked (Sula dactylatra) and Nazca (S. granti) boobies recorded in California. I evaluated a total of 134 individuals initially discovered between 5 April 1990 and 19 November 2019. For each individual I scored the stage of molt of the primaries, coloration of seven areas of the plumage, and color and brightness of both the base and tip of the bill. Two distinct bill-color patterns emerged as the birds aged from juvenile to defiitive plumage. Birds with dusky, horn color (medium-pale brownish, oftn tinged mustard or olive), orange, and/or pink in the bill base commonly had brighter orange-yellow or golden yellow but not green in the bill tip. By contrast, birds with dark blue, green, and/or yellow in the bill base commonly had green and/or yellow but not orange in the bill tip, and the tip was less oftn brighter than the base. I propose that the fist category represents Nazca Boobies and the second represents Masked Boobies. A horn-colored base and a brighter golden-yellow tip of the bill of birds in their fist and second plumage cycles (including most juveniles) evidently indicates the Nazca Booby. Some birds probably reach defiitive appearance by completion of their fist primary molt, at 20–22 months of age. Th central rectrices of apparent Nazca Boobies (by bill color) average whiter than those of apparent Masked Boobies, the extent of white increasing from juvenile to second basic to defiitive plumage. But there is species overlap in this feature. According to provisional identifiations in my sample, Nazca Boobies have outnumbered Masked Boobies in California (92 vs. 27 individuals through 2019).

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    RICHARD A. ERICKSON, STEPHEN C. ROTTENBORN (Author)

    TWO PHOTOGRAPHED AMERICAN COOT × COMMON GALLINULE HYBRIDS

     To the three previous reports of hybrids of the American Coot × Common Gallinule we add two, one from Mountain View, California, in July 1995 and one from Tijuana, Baja California, in December 2019 and January 2020. Th hybrids were similar in their coot-like build and intermediate plumage coloration, but they diffred in size, bill and leg coloration, extent of lobes on the toes, and some plumage details. Th one in Tijuana was larger than either parental species but made vocalizations of both species. Such intergeneric hybrids are rare, but at least 11 examples of  Fulica ×  Gallinula have been reported from the Old World.

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    W. David Shuford (Author)

    COURSE REVIEW: Learning California Bird Sounds, 4th edition

     Bird sounds are a conspicuous part of the natural world that delight the ear, mark the changing seasons, pique our curiosity, and provide the background music to daily life. Besides bringing us simple pleasure, the study of bird sounds can open us to an entirely new world as we learn new languages that allow us to identify species and eavesdrop on their communications sight unseen. Anyone who has spent any time in the fild knows how important it is to master the basic songs and calls of birds given how many individuals are heard only rather than seen. Knowledge of bird songs is also vital to conservation work, as detecting population trends of species, from the rarest to the most common, oftn depends on surveys that require aural identifiation (e.g., Breeding Bird Survey). When I began birding in the 1970s, there were few resources for learning bird songs other than some basic recordings available on LP record albums (including vocal recreations of bird calls, e.g., Big Jake’s Calls the Waders; www.discogs.com/Big-Jake-Calls-Th-Waders-/release/7763703), verbal descriptions of songs and calls in fild guides and other books, and fild outings with more accomplished companions. Today, aftr the dawn and maturation of the digital age, there is a dizzying array sources, including online access to worldclass sound-recording collections, such as Cornell Lab of Ornithology’s Macaulay Library (www.macaulaylibrary.org) or Xeno-canto (www.xeno-canto.org/), recent fild guides devoted entirely to bird song (e.g., Nathan Pieplow’s 2019 Peterson Field Guide to Bird Sounds of Western North America, Houghton Miffl Harcourt), and various smartphone apps. Yet, many novices may fid the detail and complexity contained in such sources daunting and may seek guidance from other introductory or regionally focused materials.

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    AUSTIN R. YOUNG, LIAM M. WATERS (Author)

    FIRST RECORD OF THE PURPLE MARTIN BREEDING IN IDAHO

     Th Purple Martin (Progne subis), the largest swallow (Hirundinidae) that is widespread in North America north of Mexico, breeds commonly over much of the eastern U.S. and central Canada (Brown and Tarof 2013). Sparser and oftn isolated breeding populations are scattered through the Pacifi states (Kostka and McAllister 2005, Airola and Williams 2008) and southern British Columbia (Cousens et al. 2005), as well as the interior West from north-central Utah and western Colorado south to northern Mexico (Behle 1968, Doughty and Fergus 2002). Th location of reported breeding nearest to Idaho is about 35 km to the south in northern Utah, where Purple Martins nest mainly in abandoned woodpecker holes in mature aspen or mixed forests near water at high elevations (Hayward 1941, 1958, Brown and Tarof 2013).

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    LISA D. WALKER-ROSEMAN, KEVIN A. GIUSTI, FLOYD E. HAYES (Author)

    POST-BREEDING EXTRA-PAIR PSEUDOCOPULATION IN THE PYGMY NUTHATCH

     Nonreproductive sexual behaviors such as pseudocopulation (also referred to as noncopulatory mounting and backstanding), homosexuality, and autoeroticism have been reported in more than 230 species of birds in at least 37 families (Bagemihl 1999, Balcombe 2006). Th functions of nonreproductive sexual behaviors in birds are poorly understood. Such behaviors, which include reverse mounting during the breeding season (e.g., Nuechterlein and Storer 1989) and pseudocopulation outside of the breeding season (e.g., Short 1971), are oftn associated with courtship or pair bonding. Reverse mounting and pseudocopulation may also occur in social contexts outside of the pair bond, perhaps to maintain group dynamics by reducing aggression (e.g., MacRoberts and MacRoberts 1976, Moynihan 1990, Dawson and Mannan 1991, Hagemeyer 2016).

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    MATTHEW GRUBE (Author)

    A POSSIBLE FIRST HYBRID OF ICTERIA × ICTERUS

     On 10 September 2019, along my typical birding route along San timoteo Creek near redlands, San Bernardino County, California, I encountered a rather odd bird. about a mile into the walk I fist noticed at a distance what superfiially appeared to be a Yellow-breasted Chat (Icteria virens). It struck me as interesting initially just because I had not seen a chat well in a few weeks, because it was actually out in the open, and it allowed me to advance up to it slowly for decent photographs (Figures 1 and 2). Th bird was silent, and aftr a minute or two it flw off Th bird was unusual for a chat not only in its approachability but also in its patterned back, more greenish color on the back and head, evident wing bars, and blackish tail.