Birding 06-06 News & Notes 4/13/06 3:16 PM Page 26 NEWS AND NOTES by Paul Hess New Splits in Britain structure and pigmentation, but differences in feathering at the bill base, in tracheal structure, and in courtship vocal- Canada Goose, White-winged Scoter, and Black Scoter are izations are also listed. each split into two species, and Herring Gull into three, in Black Scoter becomes Common Scoter (Melanitta nigra) a flurry of taxonomic revisions by the British Ornitholo- of Eurasia, which summers widely in northern Canada, and gists’ Union. In a shuffling of Audubon’s/Little Shearwater Black Scoter (M. americana) of North America, both mono- taxa, a newly named species replaces Little Shearwater in typic. Different bill structures, bill colors, and male the northeastern Atlantic. The changes took effect for the courtship calls are said to be diagnostic. Moreover, no hy- British List in 2005 (Ibis 147:821–826). bridization between the two is known (Jon L. Dunn, per- As did the American Ornithologists’ Union in 2004, the sonal communication). BOU divides Canada Goose into a large-bodied and a small- The Herring Gull becomes three species based on dif- bodied species: Greater Canada Goose (Branta canadensis) ferences in morphology, vocalizations, and mitochondrial and Lesser Canada Goose (B. hutchinsii), which correspond DNA patterns. One retains the name Herring Gull (Larus argentatus) with subspecies argentatus and argenteus of northwestern Europe. A second is Yellow-legged Gull (L. michahellis) with subspecies michahellis of the Mediter- ranean and atlantis of the northeastern Atlantic. A third is monotypic Armenian Gull (L. armenicus) of Armenia and neighboring areas. The subcommittee is reviewing the sta- tus of American Herring Gull, which is currently classified as L. argentatus smithsonianus, but which some taxono- mists believe warrants status as a separate species. For a recent recommendation of species status for smithsoni- anus, see “The Beringian connection: Speciation in the Herring Gull assemblage of North America” (Birding July/August 2005, pp. 402–411). The subcommittee is also examining the status of Caspian Gull of eastern Eu- rope and Asia (L. argentatus cachinnans). We now face a Recent taxonomic splits adopted for the British list involve three waterfowl: Canada trans-Atlantic muddle of names: “Yellow-legged Gull” in Goose, Black Scoter, and White-winged Scoter. The British Ornithologists’Union has the AOU and ABA checklists is L. cachinnans, but it is L. separated each into two species, while dividing Herring Gull into three. Travis County, Texas; November 2005. © Greg Lasley. michahellis in the new BOU nomenclature. The AOU Check-list Committee is expected to soon review the tax- to the “new” Canada Goose and Cackling Goose named by onomy of smithsonianus and “Yellow-legged” (Dunn, per- the American Ornithologists’ Union. Subspecies assign- sonal communication). ments are the same as those of the AOU. The name Lesser In the shearwater shuffle, Little Shearwater (Puffinus as- Canada Goose is ironic because it is also the standard Eng- similis) disappears as such from the northeastern Atlantic lish name for the parvipes race of Greater Canada Goose. The Ocean. Based on a study of mitochondrial DNA sequences, British report points to genetic divergence and differences in this population is reclassified as a new species named Mac- morphology, migration timing, nesting habitat, and nest aronesian Shearwater (P. baroli), which breeds in the region structure, as well as an apparent absence of interbreeding be- called Macaronesia comprising the Azores and Canaries, tween sympatric large-bodied and small-bodied populations. Madeira, and the Cape Verde islands. This new taxon con- White-winged Scoter becomes monotypic Velvet Scoter tains subspecies baroli (for which there are specimen (Melanitta fusca) of Europe and western Asia, and polytyp- records from South Carolina and Nova Scotia) and boydi, ic White-winged Scoter (M. deglandi) containing sub- both formerly assigned to Little Shearwater. Unchanged is species deglandi of North America and stejnegeri of eastern the BOU’s classification of Audubon’s as P. lherminieri, the Asia. The BOU is considering possible species status for common small shearwater seen off the U. S. Atlantic and stejnegeri as well. The split rests primarily on different bill Gulf coasts. How does a Little Shearwater in Monterey Bay 26 BIRDING • MAY/JUNE 2006 Birding 06-06 News & Notes 4/13/06 3:16 PM Page 27 on 29 October 2003—the first documented for the U. S. 122:733–746). He recounted a century of attempts by re- West Coast—fit the picture? The BOU report does not as- searchers to identify species, to quantify migrants’ num- sess Audubon’s/Little Shearwater taxonomy worldwide. bers, to determine timing of seasonal and hourly passages, However, it cites a recent molecular analysis that divided and to delineate migration routes, all by analysis of flight taxa in the Pacific and Indian oceans and taxa in the south- calls. Farnsworth discussed flight-calling behavior associat- ern Atlantic and Australia/New Zealand seas into two ed with atmospheric conditions, altitude, and topography, monophyletic groups (i.e., having independent evolution- and he explained many functions that have been proposed ary ancestries), both separate from the North Atlantic pop- as adaptive benefits of the calls. He listed “major gaps in ulations (Auk 121:847–864). our understanding” as opportunities for future research: Why are some species silent during nocturnal migration? Are flight calls learned? What factors constrain their char- Flight Call Research acteristics? Over what distances are they effective? How variable are they within species? Few of us imagined, until a decade ago, that distinguishing Farnsworth and Evans emphasize that birders can con- a Gray-cheeked Thrush from a Bicknell’s Thrush in migra- tribute valuable scientific data on migration routes, density, tion could be easier in the dark than in the daylight. After 8 many years of studies on the Gaspé Peninsula, Stanley C. Ball had speculated in 1952 that these two thrushes’ noc- turnal flight calls might be diagnostic, but confirmation 6 was elusive. Will Russell and Davis W. Finch cautioned in the September/October 1973 issue of Birding that the only “totally unambiguous” thrush flight call appeared to be the 4 heep of Swainson’s Thrush. Russell and Finch urged birders to rise above speculation by investigating flight calls seri- 2 ously with methodical use of tape recordings. Along came Bill Evans in 1990. His famous cassette tape of nocturnal flight calls of thrushes and other species was kHz bootlegged throughout North America, leading birders to mS 0 100 200 discover that the night sky was a fabulous aural frontier. The flight calls of passerines and other land birds are most frequently given by birds on Evans soon revisited the Gray-cheeked and Bicknell’s nocturnal migration. Despite the challenge of identifying birds by their nighttime flight Thrushes with advanced technology, demonstrating with calls, there has been a recent flurry of basic interest in and applied research on noctur- sonograms in 1994 that the nocturnal flight calls of the two nal migration. Sonogram of the flight call of a Swainson’s Thrush. Figure courtesy of species were separable (Wilson Bulletin 106:55–61). Then © Bill Evans / Old Bird. came the historic CD-ROM produced by Evans and and timing of various species. “I think it is of the greatest Michael O’Brien, Flight Calls of Migratory Birds: Eastern importance to have amateur ornithologists pointing micro- North American Landbirds, covering 211 species. Since its phones at the sky. In fact, I think this is the most important release in June 2003, Evans’s nonprofit corporation named venue of all for flight call research,” Farnsworth said (per- Old Bird <www.oldbird.org> has sold more than 1,200 sonal communication). He recommends the microphone copies. For hundreds of birders: Epiphany! designs and free analytical software available on Evans’s web Such advances rest on a tradition of research reaching site. Also on the site is an article Evans wrote in 2005 ex- back to 1899 when O. G. Libby quaintly suggested that the plaining how to outfit your house as a flight call monitoring migrants’ calls he heard in Wisconsin “expressed a whole station (Passenger Pigeon 67:15–24). “By comparing their range of emotions from anxiety and fear up to good-fel- calling data, especially the proportions of different species lowship and joy” (Auk 16:140–146). Flight calls, of course, going over their recording sites, birders can really be the pi- carry a lot more meaning than that. Andrew Farnsworth, oneers in mapping gradients of nocturnal migration density who has studied nocturnal calls at the Cornell Laboratory across the continent for many species of songbirds,” Evans of Ornithology, recently reviewed the history of flight call said (personal communication). Even old birders who can- research, summarized the state of knowledge in 2005, and not hear calls overhead can share the excitement by seeing pointed toward paths for future discoveries (Auk the notes as sonograms on their computer screens. WWW.AMERICANBIRDING.ORG 27 Birding 06-06 News & Notes 4/13/06 3:16 PM Page 28 NEWS AND NOTES Marsh-nesting dra L. Wilke, Bryan D. Watts, Barry R. Truitt, and Ruth Boettcher reported the findings in 2005 (Waterbirds Oystercatchers 28:308–315). Most notable was the large number of pairs occupying the lagoon system, an environment of small low- Ornithologist Frank M. Chapman needed only a few words lying islands separated by shallow creeks and bays. There to characterize American Oystercatchers a century ago. the pairs were found breeding on patches of storm-deposit- “They are strictly maritime birds ... true beach birds,” he said ed oyster shells (“shell rakes”) and dead grasses (“wrack”), in his Handbook of Birds of Eastern North America.