Western Birds Journal

Volume 43, No. 4

Published October 1, 2012

Issue description

Volume 43, number 4 of Western Birds, published 2012

Articles

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    ANDREW B. JOHNSON (Author)

    ROBERT W. DICKERMAN: A BRIEF INTRODUCTION

    It is my greatest pleasure that I have the opportunity to introduce Dr. Robert W. Dickerman. The year 2011 marked the beginning of the seventh decade of Bob’s career as a publishing author, and is fitting that Western Field Ornithologists publish an issue of Western Birds to honor his contribution to biology. Although I and most others know him as a specimen-based ornithologist par excellence, Bob has also made lasting contributions in mammalogy, animal behavior, and human health. In order to celebrate his remarkable career thus far, the editors of Western Birds have solicited from Bob’s friends and colleagues manuscripts on subjects of interest to Bob. Those papers constitute the festschrift you see before you. We hope Bob approves.

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    RICHARD C. BANKS (Author)

    GEOGRAPHIC VARIATION IN WINTERING GREATER WHITE-FRONTED GEESE

    There is relatively little variation in size, expressed mainly in bill dimensions, between or among most wintering populations of the Greater White-fronted Goose (Anser albifrons). In the British Isles, slightly larger and darker birds, from the Greenland breeding population, winter in Ireland and Scotland and associated islands, while smaller birds winter in England. Winter birds in continental Europe are the same size as those in England. Asian winter birds average slightly larger than those of Europe; the population is more variable and includes some larger individuals. In western North America, some birds in the Sacramento Valley of northern California, the famed Tule Goose (A. a. elgasi), are the largest of the species. There is a great range of variation in smaller birds of the Sacramento Valley and elsewhere in the west coast states. Birds in the midcontinent states, east of the Rocky Mountains, average about the same as smaller California birds but vary widely.

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    JON L. DUNN, DANIEL D. GIBSON, MARSHALL J. ILIFF, GARY H. ROSENBERG, KEVIN J. ZIMMER (Author)

    ALASKA RECORDS OF THE ASIAN WHITE-WINGED SCOTER

    The three widely recognized taxa of “white-winged” scoters Melanitta–fusca, deglandi, and stejnegeri are discussed variously in the literature as one, two, or three species. Adult males of the east Asian stejnegeri are distinguished from the American deglandi primarily by their black rather than brown flanks, yellow rather than black lamelle in the bill, and usually more hooked on the bill. Since 2002, there have been four well-supported records of stejnegeri in Alaska, two at St. Lawrence Island and two near Nome. Although we saw up to four adult males of stejnegeri at St. Lawrence Island in 2009, deglandi appears to predominate there. More study is needed for the status of stejnegeri as species or subspecies to be settled.

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    ANDREW B. JOHNSON (Author)

    A VAUX’S SWIFT SPECIMEN FROM NEW MEXICO WITH A REVIEW OF CHAETURA RECORDS FROM THE REGION

    Vaux’s Swift has finally been documented in New Mexico on the basis of two observational records supported by photographs and a specimen. Here I report on the circumstances of collection of the specimen and review the status of Vaux’s and Chimney Swifts in the region. In New Mexico, Vaux’s Swift appears to be a rare but regular migrant in the fall and perhaps the spring, with most records from the southwestern part of the state. The Chimney Swift is established as an annual summer resident on the eastern plains of New Mexico with a tendency to wander farther west. More data from Chihuahua are needed.

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    CHRISTOPHER C. WITT, ROBERT W. DICKERMAN (Author)

    DIFFERENTIAL MIGRATION BY SEX IN NORTH AMERICAN SHORT-EARED OWLS

    Differential migration of the sexes is known in over 60 bird species and may be the predominant pattern in migratory birds. Identifying the causes of differential migration has been difficult, in part because sex-specific migratory patterns have yet to be described for a majority of species. We used the Internet specimen-data portal Ornis to compile sex-specific data on the seasonal distribution of the Short-eared Owl (Asio flammeus), a species that cannot be reliably sexed by external characteristics. We found 1188 specimen records from North America with data on sex, locality, and date of collection. Although the winter distributions of males and females overlapped almost entirely, the mean latitude of females was significantly lower than that of males for the months of November to March. The magnitude of the difference averaged 3.1° between December and February but increased to a peak of 6.0° in March, reflecting earlier onset of spring migration in males. The pattern of differential migration in the Short-eared Owl is compatible with the widely accepted hypothesis that males winter closer to breeding areas because they gain a reproductive advantage from early arrival and establishment of breeding territories (arrival-time hypothesis). Female specimens predominate during late fall and winter and male specimens predominate during the nesting season, suggesting differential seasonal mortality by sex. The skewed sex ratio suggests that differential migration may be caused in part by intrinsic sex differences in foraging efficiency, cold tolerance, or dominance. Comparisons with other raptors reveal that patterns of differential migration are highly species-specific. We conclude, conservatively, that the longer distance female Short-eared Owls migrate is the result of each sex optimizing its migration strategy in light of the higher likelihood of fall and winter mortality of females and the reproductive benefits to males of early arrival on breeding territories.

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    DANIEL D. GIBSON (Author)

    ON TWO FRONTS: OCCURRENCE OF THE HOUSE SPARROW IN ALASKA

    The first Alaska records of the House Sparrow (Passer domesticus), comprising birds reaching southeastern (132° W) and far western (171° W) localities in the state, probably reflect short-distance dispersals from adjacent Canada (British Columbia) and from the adjacent Russian Far East (Chukotka), respectively. Both source populations are the results of human introductions.

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    KEVIN WINKER (Author)

    THE WRETCHED RIDDLE OF REDUCED RECTRICES IN WRENS

    Hwat dostu godes a-mong monne?
    Na mo pene dop a wrecche wrenne.
    (What good do you do among men?
    No more than does a wretched wren.)

    (The Owl and the Nightingale, Middle English poem, 13th century, lines 563–566; Wells 1907)

    Most bird species possess 12 rectrices in six pairs, although the number of rectrices varies among all species from 6 to 32 (Van Tyne and Bergen 1976). Within a species, variations from the typical number of rectrices also occur, commonly in some species, and it is this type of variation that has probably attracted most attention. Audubon (1831:139, 140), for example, reported a female Carolina Parakeet (Conuropsis carolinensis) with a pair of supernumerary rectrices; he recognized it as an individual aberration and chose to highlight it in his painting of this species. Somadikara (1984) used the term “polyrecticly” for supernumerary rectrices, and Hanmer (1985) coined the term “anisorectricial” for an abnormal number of rectrices, whether in an asymmetrical or symmetrical context.

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    JACK J. WITHROW, MICHAEL T. SCHWITTERS (Author)

    FIRST NORTH AMERICAN RECORD OF THE COMMON MOORHEN (GALLINULA CHLOROPUS) CONFIRMED BY MOLECULAR ANALYSIS

    On 12 October 2010 Schwitters briefly observed a gallinule or moorhen in a small interior wetland on Shemya Island, Alaska (52° 43′ N, 174° 07′ E). In spite of considerable effort, he could not find the bird again until the evening of 14 October 2010, when it was relocated foraging in another interior wetland (Figure 1) and was collected (University of Alaska Museum [UAM] 27369). The bird likely arrived on Shemya with a decaying typhoon (Malakah) that passed just north of the island on 27 September 2010 but went undetected in the intervening time because of its secretive behavior. The specimen is a juvenile male with the following characteristics: mass 269 g, trace amounts of fat, left testis 4 × 2 mm, wing chord 169 mm, tail 62 mm, tarsus 50.1 mm, bill (from anterior edge of nares) 14.5 mm, bill height (at same point) 8.8 mm, bill width 5.2 mm, feet/legs yellow-green (Figure 2).

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    PHILIP UNITT (Author)

    CLASSIFICATION OF THE HOUSE FINCH OF THE CHANNEL ISLANDS, SOUTHERN CALIFORNIA

    The Channel Islands of southern California are renowned for their many endemic plants and animals. Among land birds, 22 endemic species or subspecies have been described. Not all of these are valid, however, and their distinctiveness spans a wide spectrum. Johnson (1972) categorized the islands’ land birds in five strata ranging from the Island Scrub-Jay (Aphelocoma insularis) of Santa Cruz Island to those not known to differ from mainland populations. The last includes both species of which no subspecies endemic to the islands have been proposed, such as the Bushtit (Psaltriparus minimus), and described subspecies whose supposed differences have been discredited or found to be insufficient to meet the criteria for recognition. These synonymized names include Colaptres cafer sedentarius van Rossem, 1944 (with C. auratus collaris; AOU 1952), Vireo mailliardorum Grinnell, 1903 (with V. h. huttoni; AOU 1908), Salpinctes obsoletus pulverius Grinnell, 1898 (with S. o. obsoletus; Grinnell 1929), Amphispiza belli clementae Ridgway, 1898 (with A. b. belli; Patten and Unitt 2002), and Melospiza melodia micronyx and M. m. clementae (the last two with M. m. graminea; Patten and Pruett 2009).

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    M. RALPH BROWNING (Author)

    BOOK REVIEW: The Feathery Tribe: Robert Ridgway and the Modern Study of Birds

    The term “feathery tribe” in the title is much too cute for what is principally a work aiming at scholarship. The author states in the preface that the “book is about what it meant to be a professional studying birds in the last quarter of the nineteenth century, how a professional class emerged, what it looked like, what roles amateurs played, and how these changes led to the science of ornithology as we practice it today” (p. ix–x). All of these are touched upon at various levels. Lewis’s chronicle includes a brief history of the Smithsonian Institution, the early growth and importance of its bird collection, the development of professional ornithology, and the influence of the American Ornithologists’ Union (AOU), with Robert Ridgway as the principal person of the story. According to the author, Ridgway was a world-renowned ornithologist who “is largely forgotten today.” Forgotten!? Countless birders and ornithologists do remember Ridgway today.

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    JOHN C. STERLING, TODD B. EASTERLA (Author)

    FEATURED PHOTO: FIRST DOCUMENTED RECORD OF A COMMON RINGED PLOVER (CHARADRIUS HIATICULA) FOR CALIFORNIA

    On 19 August 2011, Easterla discovered a second-year male Common Ringed Plover (Charadrius hiaticula) in alternate plumage—a species that had never been fully documented in California. While scanning for shorebirds on a large mudflat at the Davis Wetlands, about 7.5 km northeast of the center of Davis in Yolo County, California, he noticed a plover, slightly larger than nearby Semipalmated Plovers (Charadrius semipalmatus), with a wide, black ring across its chest, no visible eye ring, a white “Nike swoosh” above its eye, and black lores extending to the gape. It was in full alternate plumage, but because of its worn greater wing coverts, it appeared to be in its second year (P. Pyle pers. comm.). Eventually, the bird called—a whistled, mournful “too-li” that was very distinct from the call of the Semipalmated Plover. On the basis of his prior experience with this species in Russia, and with many Semipalmated Plovers, Easterla felt confident this bird was a Common Ringed Plover. He phoned Sterling and e-mailed him photographs so that Jon Dunn, Bob Gill, Dan Gibson, Guy McCaskie, and others were able to confirm the identification while attending the Western Field Ornithologists’ meeting in Sierra Vista, Arizona. Over the ensuing week, hundreds of birders observed and photographed the plover. A local television news crew recorded its calls during an interview in the field with Easterla. The record has been accepted by the California Bird Records Committee as record 2011-118 (www.californiabirds.org).