Western Birds Journal

Volume 38, No. 1

Published January 1, 2007

Issue description

Volume 38, number 1 of Western Birds, published 2007

Articles

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    SARTOR O. WILLIAMS III, JOHN P. DELONG, WILLIAM H. HOWE (Author)

    NORTHWARD RANGE EXPANSION BY THE SHORT-TAILED HAWK, WITH FIRST RECORDS FOR NEW MEXICO AND CHIHUAHUA

    We documented single Short-tailed Hawks (Buteo brachyurus) in the states of Chihuahua in April 2005 and New Mexico in May and June 2005. These are the first reports for both states. To put these records into historical and geographical context, we compiled published reports for western Mexico and Arizona and for northeastern Mexico and Texas; these indicate a steady northward range expansion by this species over the past half century, an expansion that may have accelerated in recent years.

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    W. DAVID SHUFORD, JOAN M. HUMPHREY, ROBERT B. HANSEN, GARY W. PAGE, LYNNE E. STENZEL, CATHERINE M. HICKEY (Author)

    SUMMER DISTRIBUTION, ABUNDANCE, AND HABITAT USE OF BLACK-NECKED STILTS AND AMERICAN AVOCETS IN CALIFORNIA’S CENTRAL VALLEY

    Little is known about breeding shorebirds in California’s Central Valley on which conservation actions could be based. In summer 2003, we surveyed shallow-water habitats throughout that region for Black-necked Stilts (Himantopus mexicanus) and American Avocets (Recurvirostra americana). Survey methods included ground counts, aerial surveys, and sampling of Sacramento Valley rice fields. We estimated about 30,000 Black-necked Stilts and 10,700 American Avocets in the Central Valley, exclusive of Suisun Marsh. The proportion of stilts and avocets, respectively, within four subregions were Sacramento Valley 74% and 37%, delta 1% and 1%, San Joaquin basin 2% and 7%, and Tulare basin 23% and 56%. The ratio of stilts to avocets was 5.6:1 in the Sacramento Valley, 1.1:1 in the San Joaquin Valley. The Sacramento Valley held 64% of all stilts and avocets, the Tulare basin 32%, the San Joaquin basin 3%, and the delta 1%. Key habitats were rice fields (73%), managed wetlands (10%), and sewage ponds (6%) for stilts, and rice (35%), managed wetlands (32%), agricultural evaporation ponds (14%), sewage ponds (9%), and agricultural canals (6%) for avocets. Rice held 98% of all stilts and 93% of all avocets in the Sacramento Valley. The Tulare basin had five habitats that held >10% of its total for at least one of the species and was the only region where agricultural evaporation ponds, agricultural canals and ditches, and water-storage facilities supported large numbers of shorebirds. Overall, >80% of all stilts and avocets in the Central Valley were found in environments created for agriculture, water management, or industry, where they may be exposed to toxins. Their reliance on these artificial environments is risky, as future changes to serve human economies may reduce the value of such habitats to wildlife. Thus there is a need to restore and enhance high-quality wetlands in the Central Valley to counter historic losses and potential future loss of other shallow-water habitats of uncertain reliability and sustainability.

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    JONATHAN L. ATWOOD, SUSANNAH B. LERMAN (Author)

    GEOGRAPHIC VARIATION IN CACTUS WREN SONGS

    We compared Cactus Wren (Campylorhynchus brunneicapillus) songs recorded in three regions of coastal southern California (Ventura and Los Angeles counties, Orange County, and San Diego County), Baja California, and the Sonoran and Chihuahuan deserts. On the basis of four measures of the fine structure of individual notes, songs of wrens from Baja California south of 31° N latitude were most distinct; songs of birds from the three regions of coastal southern California were similar and most like songs given by birds in Baja California. Cactus Wrens in coastal southern California are geographically isolated, morphologically different, and differ in song behavior from those in Baja California. Compared with Sonoran and Chihuahuan desert populations, Cactus Wrens in coastal southern California are geographically isolated, differ in song behavior, and occur in a unique and unusual ecological setting. These characteristics suggest that the U.S. Fish and Wildlife Service should reconsider its 1994 decision denying coastal Cactus Wrens protection under the Endangered Species Act because the population was deemed to not meet the definition of a “distinct population segment.”

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    BENJAMIN L. SAENZ, JULIE A. THAYER (Author)

    EVIDENCE OF DOUBLE-CLUTCHING BY BRANDT’S CORMORANTS ON ALCATRAZ ISLAND, CALIFORNIA

    Double clutches of eggs in the same season are rare among seabirds and, to our knowledge, never recorded heretofore in Brandt’s Cormorant (Phalacrocorax penicillatus). We report here seven cases of second clutches for this species observed at a colony recently established on Alcatraz Island in San Francisco Bay, California. Chicks hatched from two of the seven second clutches, but no chicks survived to fledge. Over eight years of observation (1997–2004), second clutches were laid from 2000 to 2003 only.

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    MARCO ANTONIO GONZÁLEZ-BERNAL, JOSÉ ALFREDO CASTILLO-GUERRERO, CECILIA DEL ROCÍO HERNÁNDEZ-CELIS, ERIC MELLINK (Author)

    NOTES: NOTEWORTHY BIRD RECORDS FROM SINALOA, MÉXICO

    To date no general account of the birds of Sinaloa has been published. The subtropics, warm desert, and montane habitats converge in Sinaloa, making the state an area of high bird diversity. Of Sinaloa’s habitats, the coast has been studied the most. This coast includes a series of wetlands known to be important to birds. For example, Bahía Santa María–La Reforma and Ensenada Pabellones, two of the best studied areas, are key stopover and wintering sites for shorebirds (Englis et al. 1994) and waterfowl (Kramer and Migoya 1989). They also sustain important populations of breeding and resident birds (Carmona and Danemann 1994, Howell and Webb 1995, González-Bernal et al. 2003). Yet ornithological research in Sinaloa has been limited, and knowledge of the state’s birds is far from complete. Here we report some noteworthy records that we have made since 1998, mostly in the two bays mentioned above, but also elsewhere along the coast and at a few inland sites.

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    STEPHAN LORENZ, DANIEL D. GIBSON (Author)

    NOTES: INTERMEDIATE EGRET (EGRETTA INTERMEDIA) IN THE ALEUTIAN ISLANDS, ALASKA

    The western Aleutian Islands, Alaska, are well known for the occurrence of migrant birds from Asia (Gibson and Byrd 2007). In addition to many Asiatic waterfowl, shorebirds, and passerines, no fewer than six taxa of Asiatic herons have occurred there. Of these herons, the Yellow Bittern (Ixobrychus sinensis), Chinese Egret (Egretta eulophotes), Little Egret (Egretta g. garzetta), and Asiatic subspecies of the Cattle Egret (Bubulcus ibis coromandus) are known from a single record each, while the Indo-Pacific subspecies of the Great Egret (Ardea alba modesta) and Old World subspecies of the Black-crowned Night-Heron (Nycticorax n. nycticorax) are both known from multiple occurrences (Gibson and Byrd 2007). To this impressive list can now be added the Intermediate Egret (Egretta i. intermedia).

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    Richard A. Erickson (Author)

    BOOK REVIEWS Biodiversity, Ecosystems, and Conservation in Northern Mexico: edited by Jean-Luc E. Cartron, Gerardo Ceballos, and Richard S. Felger. 2005. Oxford University Press. 514 pages. Hardback, $99.50. ISBN13: 978-0-19-515672-0, ISBN10: 0-19-515672-2.

    Mexico is blessed with an amazing biological heritage. It has been identified as one of 17 megadiversity countries in the world, owing largely to a high degree of endemism. It has one of the highest species counts of vascular plants and amphibians; it hosts 12% of the world’s mammal species and over 1000 bird species. And these riches are not limited to the country’s tropical southern regions: more species of reptiles are said to occur in Mexico than in any other country, thanks largely to the diversity of arid habitats found in northern Mexico; the Baja California peninsula has the highest known density of scorpion species in the world; the state of San Luis Potosí has the highest known concentration of cactus species. Facts like these are presented in this welcome volume and serve as the backdrop for further discussions regarding the conservation of these threatened resources.

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    Jay Withgott (Author)

    BOOK REVIEWS: Birds of Lane County, Oregon: edited by Alan L. Contreras. 2006. Oregon State University Press. 366 pages. 130 black-and-white photos, illustrations, and figures. Paperback, $20.00. (ISBN 0-87071-180-6).

    The size of Delaware, Rhode Island, and 26 Districts of Columbia combined, Lane County is Oregon’s sixth largest county. Stretching from the crest of the Cascades across the farmlands and wetlands of the Willamette Valley and over the Coast Range to the Pacific, its topographical diversity gives it more bird species (403 recorded) than any other county in the state.

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    LEN BLUMIN (Author)

    FEATURED PHOTO: LEUCISTIC GREBE AT MONO LAKE — AN IDENTIFICATION CHALLENGE

    From 12 to 15 October 2006 I observed and photographed a fully leucistic Podiceps grebe on Mono Lake, California. Subsequent study of the photographs raised questions about which species I had been watching and led to a review of how best to differentiate white-plumaged grebes.

    Mono Lake hosts more than 1.5 million Eared Grebes (Podiceps nigricollis) in October when most molt into basic plumage (Boyd and Jehl 1998). The grebes gorge on superabundant Mono Lake Alkali Flies (Ephydra hians) and Mono Lake Brine Shrimp (Artemia monica) before heading farther south for the winter (Cullen 1999).

    Within minutes of our arrival at Mono County Park in the mid-afternoon of 12 October 2006 Patti Blumin, my wife, spotted a white grebe, and we watched it for the next 30 minutes as it foraged at the surface and occasionally dove. The bird’s behavior differed from that of the neighboring Eared Grebes; it dived more frequently and occasionally swam like a merganser with just its head below the surface. We relocated and photographed the leucistic grebe on 14 and 15 October, and we later learned it had been spotted earlier by Jim Dunn on 7 October.

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    WESTERN FIELD ORNITHOLOGISTS: 32ND ANNUAL MEETING: 27–30 September 2007 Henderson, Nevada

    The 32nd annual meeting of Western Field Ornithologists will be held near Las Vegas, Nevada, 27–30 September 2007, at Sam’s Town Resort and Casino in Henderson, Nevada. The local area host for this meeting is the Red Rock Audubon Society. A diverse conference is being planned with half-day and full-day field trips, science sessions, expert panels, workshops, and social activities. The release of the highly anticipated Nevada Breeding Bird Atlas in 2007 will add a special dimension to the meeting. Chris Elphick, editor of The Sibley Guide to Bird Life and Behavior, will give the keynote address.