April 1993] ShortCommunications andCommentaries 385

L^CK,D. 1971. Ecologicalisolation in birds. Black- SUMMERS-SMITH,D. 1963. The House Sparrow. Col- well Scientific Publications, Oxford. lins. London. LOWTHER,P. 1983. Breedingbiology of House Spar- SUMMErS-SMITH,J. D. 1988. The sparrows. Poyser rows: Intercolony variation. Occas.Pap. Univ. Ltd., Calton, United Kingdom. Kans. Mus. Nat. Hist. 107:1-17. VONHAARTMAN, L. 1971. Populationdynamics. Pages MACKENZIE,J. M.D. 1946. Somefactors influencing 392-461 in Arian biology, vol. 1 (D. S. Farner and woodland birds. Q. J. For. 40:82-88. J. R. King, Eds.). Academic Press, New York. NORUSiS,M.J. 1985. SPSSXadvanced statistics guide. Z^R, J.H. 1984. Biostatisticalanalysis, 2nd ed. Pren- McGraw-Hill, New York. tice-Hall, EnglewoodCliffs, New Jersey. PtNOWSKt,J. 1967. Die Auswahl desBrutbiotops beim Feldsperling (Passerm. montanusL.). Ekol. Pol. 15: Received3 August 1992, accepted29 November1992. 1-30.

The Auk 110(2):385,1993

Song Differences Between North American and European White-winged Crossbills( Loxia leucoptera)

JOHAN ELMBERG Departmentof AnimalEcology, Swedish University of AgriculturalSciences, S-901 83, Umer•,Sweden

Accordingto my experience,the songof the White- bill have received little attention (cf. Griscom 1937). winged Crossbill (Loxialeucoptera; referred to as the Thus, better knowledge of the song (and other vo- Two-barred Crossbill in Europe) in eastern Canada is calizations)of the White-winged Crossbillis needed distinctly different from that of Fennoscandianbirds. from all parts of its range. I especially urge birders I heard about 20 singing individuals in New Bruns- and professionalzoologists to record and describe wick, Canada, in August 1991. They all had a song singing White-winged Crossbillsfrom easternRussia, similar to that generally describedin North American western North America, and Hispaniola, where the field guides.This songincludes a long seriesof loud geographicallyisolated L. I. megaplagaoccurs. trills on different pitches,each trill being monoto- I thank Jeff Groth and Krister Mild for comments nous and reminiscent, for example, of a singing on a draft of this note. I thank Claude Chappuis,Jean Greenfinch(Carduelis chloris), a calling CommonRed- C. Roch• and Richard Ranft (National Sound Archive poll (Acanthisfiammea), or a singing Arctic Warbler in London, United Kingdom) for information con- (Phylloscopusborealis). Four recordings of singing cerning recordings.Special thanks are due to Andrea White-winged Crossbillsfrom Ohio and Maine, sup- L. Priori and RobertaSwan at the Cornell Laboratory plied by the Cornell Laboratoryof Ornithology, all of Ornithology,Ithaca, New York,for providingNorth featurethe samesong type. American recordings. In contrast,the White-winged Crossbillsthat I have heard in Sweden and Finland (June-October) all have LITERATURE CITED had a very different song. It is rich and varied, con- sistingmainly of clear(metallic) and slurredwhistles, ELMBERG,J. 1991. Flight calls of Two-barred Cross- but also of chattersand wheezes. This song is fre- bill. Br. Birds 84:344-345. quently interspersedwith any of the three basicflight GRISCOM,L. 1937. A monographic study of the Red calls (Elmberg 1991). This song type, thus, is remi- Crossbill. Proc. Boston Soc. Nat. Hist. 41:77-210. niscentof the songof the Red Crossbill(L. curvirostra) GROWH,J. G. 1988. Resolutionof cryptic speciesin or the Parrot Crossbill(L. pytyopsittacus).Note that Appalachian Red Crossbills.Condor 90:745-760. the recordingof a singing White-winged Crossbillon KNOX, A. G. 1990. Identification of Crossbill and All the Bird Songsof Europe(Roch• 1990) is also a Scottish Crossbill. Br. Birds 83:89-93. Canadianbird (JeanC. Roch• pets. comm.). ROCHE,J.C. 1990. All the bird songsof Europe.Four Recentsuggestions of the occurrenceof crypticspe- compact discs. Sittelle, La Mute, France. ciesin the Red Crossbill(Groth 1988)highlights the TYRBERG,T. 1991. Crossbill(genus Loxia) evolution importanceof knowingwhether the song of theWhite- in the West Palearctic--A look at the fossil evi- winged Crossbill differs consistentlybetween the dence. Ornis Svecica 1:3-10. Palearcticand the Nearctic.In comparisonwith its closestrelatives (see Knox 1990, Tyrberg 1991), the Received27 April 1992, accepted15 June1992. taxonomyand phylogenyof the White-wingedCross-