Western Birds
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WESTERN BIRDS Vol. 46, No. 1, 2015 Western Specialty: Aleutian Song Sparrow Williamson’s Sapsucker probing sap well with wood flake. Photo by Lucas H. DeCicco of Anchorage, Alaska: Aleutian Song Sparrow (Melospiza melodia sanaka) Dutch Harbor, Unalaska Island, Alaska, 1 October 2011. In this issue of Western Birds (pp. 28–48), Jack J. Withrow outlines the avifauna of Chirikof Island, the most isolated island south of the Alaska Peninsula, whose birds have heretofore been virtually unknown. The discovery of Melospiza melodia sanaka on Chirikof, along with that of two other characteristically Beringian subspecies, Troglodytes pacificus semidiensis of the Pacific Wren and Leucosticte tephrocotis griseonucha of the Gray-crowned Rosy-Finch, represents an eastward extension of the known ranges of those taxa. Melospiza melodia sanaka ranges west in the Aleutians to Seguam Island, beyond which it is replaced by the even larger M. m. maxima. In this photo, the bird’s feeding on a mussel dramatizes the littoral habits of all the subspecies Williamson’s Sapsucker apparently feeding on sap from the wood flake. of the Song Sparrow distributed along Alaska’s southern coasts. Photos by Anthony J. Brake Volume 46, Number 1, 2015 Apparent Hybrid Downy Woodpecker × Hairy Woodpecker in Colorado Steven G. Mlodinow, Tony Leukering, Tayler Brooks, and Nick Moore ...................................................2 Nevada Bird Records Committee Report for 2013 Martin Meyers ............................................................................8 Notes on the Birds of Chirikof Island, Alaska Jack J. Withrow .........28 Breeding of the Ashy Storm-Petrel in Central Mendocino County, California Harry R. Carter, Michael W. Parker, Josh S. Koepke, and Darrell L. Whitworth ................................49 NOTES Haemorhous cassinii vinifer is Valid Robert W. Dickerman ............66 Is the Long-eared Owl Dimorphic? Robert W. Dickerman ..............68 Western North American Records of Eurasian Bar-tailed Godwits Nicholas R. Hajdukovich, Lucas H. DeCicco, and Pavel S. Tomkovich ............................................................71 Golden Eagle Mortality at a Wind-Energy Facility near Palm Springs, California Jeffrey E. Lovich ................................76 Acorn Woodpecker Predation on the Western Fence Lizard in Northern California Jackson D. Shedd ..................................81 Book Reviews David Vander Pluym and Jon Feenstra ...................83 Thank You to Our Supporters .........................................................88 Featured Photo: Possible Tool Use by a Williamson’s Sapsucker Anthony J. Brake and Yvonne E. McHugh .................................89 Front cover photo by © Rick Fridell of Hurricane, Utah: Nevada’s first Rufous-backed Robin (Turdus rufopalliatus), Williams Ranch, Lincoln Co., Nevada, 15 November 2012. Back cover: “Featured Photos” by © Anthony J. Brake of Richmond, California: Williamson’s Sapsucker (Sphyrapicus thyroideus) ap- proaching a flake of wood wedged in a bark crevice (top) and carrying the flake toward a sap well (bottom)—implying making and use of a tool. Inyo National Forest, Mono County, California, 17 June 2013. Western Birds solicits papers that are both useful to and understandable by amateur field ornithologists and also contribute significantly to scientific literature. The journal welcomes contributions from both professionals and amateurs. Appropriate topics include distribution, migration, status, identification, geographic variation, conserva- tion, behavior, ecology, population dynamics, habitat requirements, the effects of pollution, and techniques for censusing, sound recording, and photographing birds in the field. Papers of general interest will be considered regardless of their geographic origin, but particularly desired are reports of studies done in or bearing on North America west of the 100th meridian, including Alaska and Hawaii, northwestern Mexico, and the northeastern Pacific Ocean. Send manuscripts to Daniel D. Gibson, P. O. Box 155, Ester, AK 99725; avesalaska@ gmail.com. For matters of style consult the Suggestions to Contributors to Western Birds (at www.western fieldornithologists.org/docs/journal_guidelines.doc). Volume 46, Number 1, 2015 APPARENT HYBRID DOWNY WOODPECKER × HAIRY WOODPECKER IN COLORADO STEVEN G. MLODINOW, 2218 Watersong Circle, Longmont, Colorado 80504; [email protected] TONY LEUKERING, 1 Pindo Palm St. W, Largo, Florida 33770; [email protected] TAYLER BROOKS; 2453 239th Place SW, Brier, Washington 98036; [email protected] NICK MOORE; 1850 Arroya Street, Colorado Springs, Colorado 80906; [email protected] ABSTRACT: In external appearance, a confounding Picoides woodpecker encoun- tered in Lamar, Prowers County, Colorado, on 15 May 2014 was closest to the Downy Woodpecker (P. pubescens), though its bill appeared oversized and its supercilium narrow. But its vocalizations closely resembled those of the Hairy Woodpecker (P. villosus). Examination of photographs and sound spectrograms of this individual strongly suggest that it was a hybrid between the Downy and Hairy Woodpeckers, a previously unreported combination. On 15 May 2014, Mlodinow and Moore were birding at Lamar Com- munity College in Lamar, Prowers County, Colorado, where a small stream runs through a narrow riparian corridor dominated by Plains Cottonwood (Populus deltoides) with a scattering of Green Ash (Fraxinus pennsylva nica). They heard a woodpecker “rattle” that sounded much like that of a Hairy Woodpecker (Picoides villosus) and quite different from the “whinny” of a Downy Woodpecker (P. pubescens). Almost immediately, the bird landed close to the observers, still giving rattle calls. The observers initially assumed it was a Hairy because of its vocalizations, though Moore did comment that the woodpecker seemed rather small for a Hairy, though large for a Downy. Both observers then noted the woodpecker’s limited white spotting on the wing coverts, consistent with a (presumed at the time) vagrant Hairy Woodpecker from the Rocky Mountains (P. v. monticola) rather than the nominate race of the Hairy expected on the Great Plains of eastern Colorado. Therefore, they considered subspecific identification before visually confirming the species 2 Western Birds 46:2–7, 2015 APPARENT HYBRID DOWNY WOODPECKER × HAIRY WOODPECKER involved. Mlodinow quickly began photographing the bird, and as he did so, both he and Moore became aware of problems with its identification. It then gave a couple “peek” calls, sounding to Mlodinow and Moore much more like a Hairy Woodpecker than a Downy. Moore quickly realized the importance of documenting the vocalizations and obtained audio record- ings of the “peek” notes. For an excellent in-depth introduction to sound spectrograms, see Nathan Pieplow’s website http://earbirding.com/blog/ specs; for simplicity’s sake, we “lump” harmonic and partial harmonic in the discussion below. Although Short (1982), followed by Pyle (1997), lumped the Hairy Woodpeckers of the Colorado Rockies (median coverts unspotted) in sub- species septentrionalis (median coverts spotted; type locality Saskatchewan River, Saskatchewan), in the lack of a quantitative analysis supporting a heterogeneous subspecies that bridges a fundamental division of the Hairy Woodpecker, we use monticola (type locality Boulder County, Colorado) as the name for the birds of the Colorado Rockies (Bailey and Niedrach 1965, Leukering 2011) DISTINGUISHING THE DOWNY AND HAIRY WOODPECKERS In considering the identification of the Downy and Hairy Woodpeckers, it is important to understand that the interior montane subspecies of both differ substantially from their eastern counterparts (Leukering 2011). In both species, individuals from the Rocky Mountains have far less spotting on their wing coverts, tend to have a smaller white oval on the back, and have more black on the face (Mlodinow, Leukering pers. obs.) Additionally, montane Downy Woodpeckers (P. p. leucurus) average fewer black bars on the tail than do eastern birds (Pyle 1997), and montane Hairy Woodpeckers have a red nape spot that is not bisected by black as in eastern birds (Sibley 2000). Size Where the two species overlap, the Hairy Woodpecker averages con- siderably larger than the Downy. Male Hairy Woodpeckers from Colorado have a mean wing chord 130 ± a standard error of 1 mm and a mean tail length of 84.1 ± 1 mm (Jackson et al. 2002). Male Downy Woodpeckers from western Colorado and areas to the west in the Rocky Mountains have a mean wing chord of 101.1 ± 1 mm and a mean tail length of 64 ± 1 mm (Jackson and Ouellet 2002). Bill Length and Shape The bill of the Hairy Woodpecker is longer and appears heftier in com- parison to the shorter and more delicate appearing bill of the Downy. The mean bill length of Hairy Woodpeckers from Colorado is 35.8 ± 0.3 mm (Jackson et al. 2002), whereas that of Downy Woodpeckers from western Colorado and areas to the west in the Rocky Mountains averages 16.6 ± 0.4 mm (Jackson and Ouellet 2002). Additionally, the ratio of bill length to nasal-tuft length (front to back) is typically about 1.75 in the Downy and nearly always greater than 2.0 in the Hairy (Leukering unpubl. data). 3 APPARENT HYBRID DOWNY WOODPECKER × HAIRY WOODPECKER Plumage Downy Woodpeckers from the Rocky Mountains eastward have zero to two full black bars on the tail beyond the longest undertail covert, whereas Hairy Woodpeckers lack barring on the tail, except in some specimens of subspecies harrisi and picoideus along the coast