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AbstractRed Crossbill (Loxia curvirostra) of Type 1 hasbeen considered chiefly an Appalachian bird,though detections of this Type as far away fromAppalachia as New England and the Pacific

Northwest have at times called this associationinto question. In this paper, we review evi-dence in support of this association (n=186Appalachian recordings of Type 1, n=14 non-Appalachian recordings of Type 1), including

records of our own, and also adduce the broad-er natural history of this Type, using primarilyrecent records of calling birds that have beenidentified by audiospectrographic analysis. Wereview evidence that Type 1 is not a specialiston a single species of conifer (as some Typesappear to be), and from that we infer that wan-derings away from the core breeding range inAppalachia are driven by cone crop failures ofseveral species. We further suggest that wan-dering Type 1 birds, which have medium-sizedbills among the Red Crossbill Types, settlemost readily in areas where cone sizes andtypes are most similar to those found in corerange. We urge observers to audio-record RedCrossbills wherever they are detected and tonote the species of conifer in which they areobserved, to increase our understanding oftheir complex natural histories.

Background: Red Crossbill Types and their natural historiesRed Crossbill (Loxia curvirostra) has been di-vided into ten “call types” (hereafter Types 1-10) in North America; in addition to differ-ences in flight calls, small but significant dif-ferences in bill morphology, ecology, and ge-netics distinguish these Types (Groth 1993c,Benkman 1999, Parchman et al. 2006, Irwin2010). Groth (1993c) was the first to assertthat the Types meet criteria for full-species sta-tus under both phylogenetic and biologicalspecies concepts and that they should there-fore be recognized as taxonomic species. Morerecent studies continue to inform discussion ofRed Crossbill’s taxonomic status. Sewall (2009,2011) and Sewall and Hahn (2009) present ev-idence to support the ideas that Red Crossbillflight calls are an example of reliable signalingand that adults show limited learning of vocal-izations. Benkman (2007) and Benkman et al.(2009) argue that Types are effectively repro-ductively isolated. Interbreeding betweenTypes seems to be relatively rare, despite sym-patry of several Types and widespread wander-ing by many Types. In several published stud-

Status and distribution of Type 1Red Crossbill (Loxia curvirostra): an Appalachian Call Type?

Status and distribution of Type 1Red Crossbill (Loxia curvirostra): an Appalachian Call Type?

MATTHEW A. YOUNG • CORNELL LAB OF ORNITHOLOGY • 159 SAPSUCKER WOODS ROAD, ITHACA, NEW YORK 14850 • (MAY6@CORNELL.EDU)KEN BLANKENSHIP • 2400 BARRETT CREEK BOULEVARD #827, MARIETTA, GEORGIA 30066 • (KENHBLANKENSHIP@COMCAST.NET)MARILYN WESTPHAL • P. O. BOX 1427, HENDERSONVILLE, NORTH CAROLINA 28793 • (MJWESTPH@RET.UNCA.EDU)STEVE HOLZMAN • 349 JEFFERSON ROAD, BISHOP, GEORGIA 30621 • (STEVE_HOLZMAN@YAHOO.COM)

This Red Crossbill was audio-recorded and confirmed as Type 1, a Type that appears to be predominantly an Appalachian bird.This individual was photographed along Persimmon Road, Clayton, Georgia on 5 July 2008. Photograph by Darlene Moore.

STATUS AND DISTRIBUTION OF TYPE 1 RED CROSSBILL: AN APPALACHIAN CALL TYPE?

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ies, interbreeding between various Types hasbeen estimated at up to 5% (Groth 1993b,Summers et al. 2007, Benkman et al. 2009). Inthe South Hills of Idaho, where the residentpopulation (Type 9) occurs sympatrically withTypes 2 and 5, interbreeding was found to beless than 1% among 1704 paired crossbills(Benkman et al. 2009). Similarly, in a Euro-pean study of sympatrically occurring Red (orCommon) Crossbills (L. curvirostra), ParrotCrossbills (L. pytyopsittacus), and ScottishCrossbills (L. scotica), Summers et al. (2007)found evidence of hybridization in approxi-mately 5% of pairs, mostly between the larger-billed Parrot Crossbill and Scottish Crossbill.In a study of sympatrically occurring Types 1and 2 in the mountains of Virginia and NorthCarolina in the 1980s, Groth (1993b) foundthat all 60 monitored birds paired with mem-bers of their own Types.Types differ in bill depth and palate groove

structures, and Benkman (1993a) proposedthat each Type is most efficient at feeding onsingle key species of conifer, although notobligatorily. Other authors have proposed thatcertain Types have core zones of occurrencewhere they regularly breed and are most com-mon (Dickerman 1987, Knox 1992, Kelsey2008, Young 2010a). While most Types do ap-pear to forage most efficiently on a singlespecies of conifer when in their core zone of oc-currence (Benkman 1993a), they also feed onseeds of multiple coniferous species and can beseen switching to those conifers that providethe highest energy yields throughout the conecycle (Benkman 1987, 1988). In North Ameri-ca, Benkman (1993a) indicates that Type 2 ap-pears to be most efficient at feeding on Pon-derosa Pine (Pinus ponderosa scopularum), Type3 on Western Hemlock (Tsuga heterophylla),Type 4 on Douglas-fir (Pseudotsuga menziesiimenziesii), and Type 5 on Lodgepole Pine (Pi-nus contorta). Benkman (1993b) suggests thatType 8 feeds most efficiently on Black Spruce

(Picea mariana). And Benk -man et al. (2009) note thatType 9—which has alreadybeen proposed as a fullspecies, South Hills Crossbill(L. sinesciurus)—feeds mostefficiently on an isolated pop-ulation of Lodgepole Pine.

Benkman (1993a) further predicted the exis-tence of a Sitka Spruce (P. sitchensis)-associatedType—and indeed Irwin recently (2010) de-scribed Type 10 in the coastal Sitka Spruceforests of northern California.The evolution of dietary specialization in

crossbill Types is readily understandable ininsular populations such as those of New-foundland Red Crossbill (Benkman 1989,Benkman 1993b, Benkman and Parchman2009) or Hispaniolan Crossbill (L. megapla-ga) (Benkman 1994); it is also clear how is-land-like geography, such as Idaho’s SouthHills, could give rise to differentiated cross-bill populations, particularly where relativelystable cone crops are found (Benkman et al.2009). Such specialization in other Types isless clearly motivated and indeed is not yet

conclusively documented for a few; definitiveevidence of specialization for a primaryconifer is lacking for Types 1, 6, and 7.Benkman (2007) suggested that Type 1 mightspecialize on Red Spruce (P. rubens), a specieslargely confined to the Northeast (definedhere as the area from the Adirondack Moun-tains northward and northeastward to theCanadian Maritimes). However, Red Spruceis also found in small isolated pockets alongthe spine of the central and southern Ap-palachians from Pennsylvania to North Car-olina, and Groth originally thought thatmedium-billed Type 1 might be primarily anAppalachian bird, but he later recorded twoType 1 birds in British Columbia and setaside the concept of an Appalachian RedCrossbill (Groth 1993c).

Figure 1. A male Type 1 Red Crossbill with a fledgling visible in the left part of the frame (at left); the same male is shownfeeding a different fledgling (right). These birds were audio-recorded and photographed in Rabun County, Georgia on 25April 2009. Images from video by Ken Blankenship.

Figure 2. Audiospectrograph of Type 1Red Crossbill, considered diagnostic,recorded 19 June 1983 in MontgomeryCounty, Virginia by Jeffrey Groth. Thedark horizontal marks on the right sidesof image are for kHz lines 3, 5, and 7.Image used and adapted from Groth(1993a) with permission of the author.

Table 1. Estimated conifer seed usage through the cone cycle year (June through May) for Type 1 Red Crossbill, as wellas usage of insects and bird feeding stations. These estimates are based on our field observations, as well as on our un-derstanding of cone-ripening phenologies and Type 1’s bill morphology. Southeast (SE) and Northeast (NE) are abbrevi-ated herein.Conifer/Area Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr MayWhite Spruce (NE) X X X X X-x X-x X-x x-o x-o x-oRed Spruce (NE and SE) X X X X X-x X-x x-x x-o x-o x-o x-oEuropean Larch (Southern New York) x x x x x x x x x x x xWhite Pine (East) x X X X X-x X-x x-o x-oEastern Hemlock (East) x x x x x x x x x x xRed Pine (NE) x-X X X XVirginia Pine (mostly SE) x-X X X XPitch Pine (mostly SE) x-X X X XShortleaf Pine (SE) x-X X X XLoblolly Pine (Georgia) x-X X X XNorway Spruce (Southern New York) x x x x-X X X X XInsects x xFeeders o-x o-x o-x o-x x xKEY:X = used oftenx = used less frequentlyX-x = birds are using resource less and starting to transition to other conifersx-X = birds are transitioning from other conifers to a new conifero-x = birds could start utilizing alternative resource (e.g., feeders), depending on availability of othersx-o = birds have exhausted resource

History of Type 1 in the Appalachian MountainsMcNair (1988) provides a thorough review of historical RedCrossbill breeding records from the southern Appalachians,from the Virginias to Georgia. Griscom (1937) was among thefirst to suggest explicitly that a quasi-resident crossbill inhabit-ed the Appalachians. Subsequently, Stupka (1963) and Simpson(1974) found Red Crossbills breeding regularly in the moun-tains of North Carolina and Tennessee, and Scott’s (1981) ob-servations led him to suggest that a mostly resident populationexisted on Shenandoah Mountain in the Virginia Appalachians.Later in the 1980s, as he began to describe the various dif-

ferences in Red Crossbill Types, Groth (1988) noted that Type1 was consistently findable in the western mountains of Vir-ginia and North Carolina. In 1993, Douglas Gross document-ed Type 1 breeding in Pennsylvania (Hess et al. 1998), and in1995, Type 1 was recorded in mature, second-growth forests ofWhite Pine and Eastern Hemlock (Tsuga canadensis) in RabunCounty, Georgia (Oberle and Forsythe 1995). Type 1 has beenreported in 1998-2000 at Caesar’s Head, South Carolina, veryclose to the North Carolina border (Pitts 1988; AndrewFarnsworth, pers. comm.), although these have not yet beenverified by recordings. Type 1 has also been confirmed inGeorgia in 2008-2010 (Blankenship et al. 2010), with nestingconfirmed in April 2009 (Figure 1). Type 1 was recorded atBald Knob Ridge, North Carolina in July and August 2009 (byM. Westphal) and confirmed by audiospectrographic analysis(M. Young). In addition, Type 1 has been documented insouthern New York annually 2004-2011, sometimes in large

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Table 2. Totals of Red Crossbills from Red Spruce areas of the Appalachiansin North Carolina during mid- through late May surveys conducted by Mar-ilyn Westphal. Note the absence of Red Crossbills on most May surveys.

Date / Location Black Mountains Balsam Mountains BuncombeMay 2006 18 0 0May 2007 0 0 0May 2008 0 (no survey) 0May 2009 0 0 0May 2010 1 0 0May 2011 32 2 0

Figure 3. a) Type 1 flight call, recorded by Gregory F. Budney and Matthew A.Young at Georgetown, New York, 5 August 2006 (Macaulay Library of Sounds#137497). b) Type 1 flight call, recorded by Grant McCreary in Dawson County,Georgia, 29 May 2008 (see Blankenship et al. 2010). c) Type 1 flight call,recorded by Matthew A. Young at Pharsalia, New York, 26 July 2008. d) Type 1flight call, recorded by Ken Blankenship in Rabun County, Georgia, 25 April 2009(see Blankenship et al. 2010). e) Type 1 “variant” flight call (see Young 2010a),recorded by Matthew A. Young at Fabius, New York, 28 March 2009 (Macaulay Library of Sounds #139452). f) Type 1 flight call, recorded by Marilyn Westphalat Bald Knob Ridge, North Carolina, 22 August 2009. g) Type 1 flight call,recorded by Matthew A. Young at Georgetown, New York, 5 September 2009(Macaulay Library of Sounds #139448). h) Type 1 flight call, recorded byMatthew A. Young at West Fulton, New York, 17 January 2010 (Macaulay Libraryof Sounds #139455). i) Type 1 flight call, recorded by Matthew A. Young at Ger-man, New York, 30 July 2010 (Macaulay Library of Sounds #139454). j) Type 1flight call, recorded by Mike Nelson along Clingman’s Dome Road, Great SmokyMountains National Park, North Carolina, 1 March 2011. k) Type 1 flight call,recorded by Diane Lepkowski and William Leigh in western Rockingham County,Virginia (within several miles of the West Virginia border), 1 May 2011. l) Type 1flight call, recorded by David Caton and David Kirschke at Erwin, Tennessee, 19May 2011. m) Type 1 flight call, recorded by Ken Blankenship at Hale Ridge,Georgia, 27 June 2011. n) Type 1 flight call, recorded by Matthew A. Young at Otselic, New York, 2 July 2011. Audiospectrographs by Matthew A. Young.

numbers and often breeding (e.g., in 2004,2007, and 2009) (Young 2011). Thus, al-though the evidence is patchy, there are nowconfirmed records of Type 1 Red Crossbillsnesting along the length of the Appalachians,from northern Georgia to southern New York.Since Groth began to audio-record Red Cross-bills in the early 1980s, we have located 186recordings of Type 1 from southern New Yorkto northern Georgia, whereas in exhaustiveanalyses of thousands of recordings fromacross the continent, we know of only 14 non-Appalachian recordings of Type 1 (Table 3).Red Crossbill Types are defined, and con-

clusively documented, primarily by distinctiveflight calls. All of the records noted above,with the exception of the South Carolinarecords, have been verified to refer to Type 1Red Crossbill by audiospectrographic analysis,currently the only way to confirm identifica-tion of this Type. Type 1’s flight call shows adownward modulated component (Figures 2,3). Type 2, which has often been documentedin the vicinity of Type 1, has a similar flightcall. The audiospectrograph of Type 1’s flightcall almost invariably commences with an ini-tial upward component, and the downwardpart descends more quickly than in Type 2’sflight call (Groth 1988, 1993c). Both Typescan have secondary elements toward the endof the flight call, but these elements tend to bemuch more common and prominent in Type1. To differentiate between these two Typeswith certainty, audiospectrographic analysis isessential. In comparison to the flight call ofType 2, that of Type 1 is described as a quick-er, drier, and sharper and is sometimes tran-scribed as chewt-chewt-chewt (Evans andO’Brien 2002, Young 2008a). Type 2 flightcalls sound a bit more robust, huskier, lowerin pitch, and more modulated than those ofType 1 (Young 2008a).

Ecological associations and movementsaway from the southern AppalachiansTo analyze the movements and ecological as-sociations of Type 1 Red Crossbills, an under-standing of the phenologies of the conifersused by this Type is vital. Spruces (Piceaspp.), larches (Larix spp.), and hemlocks(Tsuga spp.), all soft-coned conifers, developcone crops in May and June, and their conesmature during the following July throughSeptember (Benkman 1987). These soft-coned conifers typically drop much of theirseed by November and December except inexcellent or “bumper” cone crop years. Thesemi-soft-coned white pines—Eastern WhitePine (P. strobus), Western White Pine (P. mon-ticola), and Limber Pine (P. flexilis)—form

conelets that mature the following year inJune and July. These species are also relative-ly inefficient at holding seed except in thebest cropping years. Hard-coned pines suchas Red (P. resinosa), Shortleaf (P. echinata),Pitch (P. rigida), Virginia (P. virginiana),Lodgepole, and Ponderosa develop immaturegreen cones during May and June. Thesecones do not start to mature until the follow-ing year in September and October. Hard-coned pines hold their seed longer than doother conifers, providing crossbill food dur-ing critical times of limited food supply in latewinter and early spring (Benkman 1993a).Red Crossbills may nest almost throughout

the year (Adkisson 1996). In New York, andprobably in other areas, Type 1 Red Crossbillsappear to nest primarily in two peaks (Young2008b, 2011): during late June–early Septem-ber, in which newly developing cone cropsare utilized, and again in January–April, inwhich the remaining seed from the previousyear’s crop is utilized. Table 1 summarizes ourobservations and inferences of seed use byType 1. In the central and southern Ap-palachians, during an average cone crop year,extending from June through the followingMay, Type 1 feeds on Red Spruce in June–Au-gust (McNair 1988, Groth 1993c, M. West-phal, pers. obs.), then on Eastern White Pinein October–February, and finally on Loblolly(P. taeda), Shortleaf, Virginia, and Pitch Pinein March–May, when all soft-coned conifershave typically dropped their seed (Groth1993c; Blankenship et al. 2010). Late winter

and early spring are also the times of the yearwhen Red Crossbills start to show up at birdfeeding stations (Benkman 2010), where theytake primarily sunflower seed. Eastern Hem-lock cones are used during the year as well,particularly when other conifers have failed.In North Carolina, Type 1 has rarely beenfound during May surveys of Red Sprucestands (Table 2), a conifer proposed as its keyfood source during spring (Benkman 2007).This is not surprising, as Red Spruce conesare mostly spent by spring.In a typical year with average cone crops,

Type 1 in New York will often use EasternWhite Pine cone crops for early nesting duringJanuary–February (Benkman 1987; M. Young,pers. obs.). In March and April, Type 1 in NewYork switches to primarily Red Pine and Nor-way Spruce (P. abies) (Young 2011), the onlytwo conifers in the Northeast that regularlyhold seed during these lean times of the year.In the southern New York counties of

Cayuga, Madison, Cortland, Onondaga andChenango, Type 1 Red Crossbills have beenpresent since at least 2004, with widespreadnesting observed in 2004 and 2007 (Young2011). They have been observed feeding andnesting in state forests where conifer planta-tions are found, including planted stands ofNorway Spruce, Red Pine, European Larch (L.decidua), Eastern White Pine, and WhiteSpruce. Also present in these areas are nativeEastern White Pine, Eastern Hemlock, and afew pockets of native Red Spruce. NorwaySpruce is perhaps the most widely planted

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Figure 4. Range of Type 1 Red Crossbill, based on published literature, documented records, and cone-ripening phenologies.Data are deficient from areas of the Northeast, Great Lakes, and West but also from areas here designated part of or near the“core zone of occurrence,” including Pennsylvania and western Maryland. Map created by Steve Holzman.

tree in the area, and unlike native spruces,this species holds its seed for as long as 14months. Seed of Norway Spruce is most ac-cessible for the crossbills beginning in Janu-ary, which coincides with a period when oth-er seed becomes scarce in the region.If central and southern Appalachian Red

Spruce crops are poor at the start the conecrop year in June and July, then Type 1 RedCrossbills are apparently forced to move, andthe primary zone of irruption is likely to bethe Northeast, specifically from central Mas-sachusetts and the Adirondacks through On-tario and the southern Maritime provinces,where soft-coned conifers are common. Oncein the Northeast, they use Red Spruce andWhite Spruce (P. glauca) during their June–September nesting period (Benkman 1987;M. Young, pers. obs.). If cone crops of manyspecies fail widely, which occurs very infre-quently (Koenig and Knops 2000, Kelsey2008), Type 1 may wander as far as the Pacific

Northwest, to coastal Sitka Spruce (Benkman1993a) and Western Hemlock forests (Groth1993c), where they are thought to be rareand, thus far, have been confirmed by veryfew audio-recordings (Table 3; Irwin 2010, T.Hahn, pers. comm.; C. Benkman, pers.comm.). Cross-continental wanderings aredocumented in other Types, e.g., Types 3 and10 have appeared in the Northeast and Penn-sylvania during irruptions (Groth 1993c,Hess et al. 1998, Young 2011). It would belogical for Type 1 to emigrate to the PacificNorthwest, where Sitka Spruce and WesternHemlock provide food resources similar toRed Spruce and Eastern Hemlock in the Ap-palachians, and although there are no returnsof audio-recorded Type 1 Red Crossbills thatwere banded in Appalachia and recovered inthe Pacific Northwest, for instance, studies inEurope (Newton 2006) verify that Red Cross-bills tend to return to natal areas after periodsof irruption due to food shortage.

DiscussionForest compositions differmarkedly between eastern andwestern North America, andcrossbill density and diversity(richness) are also quite differ-ent between the two regions,being lower in the East, higherin the more conifer-rich West.In the Pacific Northwest, par-ticularly in Washington andBritish Columbia, conifer diver-sity and density are both high,and this area also has the high-est density and diversity ofcrossbill Types (Groth 1993c).In the East, the central andsouthern Appalachians havethe highest density and highestdiversity of conifers; soft-,semi-soft-, and hard-conedconifers can be found in closeproximity in this region (Parch-man et al. 2006). The Northeastlacks a diversity of hard-conedconifers, with only Red Pine be-ing widespread. This lower di-versity may be one reason thatthe Northeast appears to sup-port no large numbers of a resi-dent Red Crossbill Type; Type10, and to a lesser extent, Type2, are found in small quasi-resi-dent numbers, with Types 3, 1,and 4 only occurring occasion-ally. To form quasi-residency,crossbills need either a singleconifer that produces a reliable

cone crop over a large enough area from year toyear, or an area that has high diversity ofconifers that provide seed from year to year(Benkman 1987). In the East, no widespreadspecies of conifer appears to produce a reliablecone crop suitable for a medium-billed crossbillsuch as Type 1, but the diversity of conifers inthe central and southern Appalachians appearsto provides sufficient cone crops, in most years,for Type 1 to be resident in this region, thoughflocks surely wander widely within the Ap-palachians (Groth 1993c, Blankenship et al.2010, Young 2011).Dickerman (1987) suggested that a medi-

um-billed Red Crossbill subspecies had disap-peared from the Northeast because of the log-ging of virgin Eastern White Pine forests in thelate 1800s early 1900s. His review of museumspecimens led him to conclude that a “North-eastern subspecies” had become nearly extinct.However, there is no acceptable evidence thatsuch a bird existed, and because Types of Red

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Table 3. Recordings of Type 1 Red Crossbills verified by audiospectrographic analysis from locations outside the Appalachians.Recordings are of one individual unless otherwise noted.

Location Date Recordist Catalog # Audiospectro-graphic Analysis Notes

Algonquin ProvincialPark, Ontario 3/20/1959 William W. H. Gunn Macaulay # 58166 Matthew A. Young Type 4 also present

Manning ProvincialPark, British Columbia 6/2/1962 William W. H. Gunn Macaulay # 58169 Matthew A. Young

Acadia National Park,Maine 6/12/1962 Robert C. Stein Macaulay # 12984 Matthew A. Young Several Type 10

also present

Thompson Plateau,British Columbia 8/8/1987 Jeffrey G. Groth Groth #jM635 (MVZ 171360) Jeffrey G. Groth Types 2, 3, 4, and 5

also present

Thompson Plateau,British Columbia 8/8/1987 Jeffrey G. Groth Groth #aF636 (MVZ 171365) Jeffrey G. Groth Types 2, 3, 4, and 5

also present

near Neilton, Washington 8/29/1989 Tom Hahn Tom Hahn Several Type 3 also

in area

Patricks Point, California 12/11/2003 Ken Irwin Ken Irwin Several Type 10also in area

Patricks Point, California 3/16/2004 Ken Irwin Ken Irwin Several Type 10also in area

Just north of PatricksPoint, California 1/7/2005 Ken Irwin Ken Irwin Three Type 1 with

several Type 10

Madawaska, New York 8/10/2008 Matthew A. Young Matthew A. Young Four Type 10 alsoin area

Near North Sandwich,New Hampshire 7/31/2009 Robert Ridgely Matthew A. Young

(see Young 2010b)

About eight Type 1birds with about24 Type 10, abouteight Type 2, andone Type 3

Sevey Corners, New York 3/4/2011 Matthew A. Young Matthew A. Young About 12 Type 10also present

East Hancock, Maine 8/4/2011 Doug Hitchcox Matthew A. Young About 24 Type 10also in area

Mary’s Peak, Oregon 8/15/2011 Doug Robinson Matthew A. Young Several Type 3 alsoin area

Crossbills are currently distinguished primarilyby flight calls, it is not feasible to evaluate Dick-erman’s hypothesis in terms of known Types. Inthe Northeast, three medium-billed Types (1, 4,and 10) are known to occur, with Type 10 be-ing the most frequently recorded in this region(Young 2010b). In addition to the Northeast’slack of a diversity of hard-coned conifers, itmay be the case that the occasional presence ofWhite-winged Crossbill (L. leucoptera) andfour other competing crossbill Types in this re-gion (Young 2011), along with abundant squir-rels (cf. Parchman and Benkman 2008), couldlimit Type 1’s ability to make regular use ofhabitats in the Northeast. In the West, small- tomedium-billed crossbills are only resident inthe wettest areas of the Pacific Northwest,where conifers hold their seeds through thewinter. The small- to medium-billed Types 3, 4,and 10 are regularly found in the Pacific North-west; thus, although this region does appear toprovide occasional refuge to Type 1 during ir-ruptions, competition with other crossbillTypes would likely limit the ability of Type 1 toestablish a stable population in this region.Based on all verified records of Type 1, as wellas the distribution of conifers known to be usedby Type 1 in areas with records, we propose anapproximate range map that illustrates the corezone of this species’ distribution along withwhat appear to be primary and secondaryzones of irruption (Figure 4).

ConclusionsGroth’s (1993c) original contention that Type1 is an Appalachian crossbill appears to besupportable. The older literature points to theexistence of a distinct quasi-resident RedCrossbill in the central and southern Ap-palachians, and in the past 25 years, the vastmajority of Type 1 sightings and audio record-ings have come from this area, but there arevery few recordings from other parts of thecontinent, and those were apparently madeonly during irruption years, probably whencone crops of multiple species failed in theAppalachians. In the conifer-rich central andsouthern Appalachians, Type 1 would experi-ence relatively little competition with otherTypes, except at the northern edge of theircore zone of occurrence, where other Typesare more frequent during irruptions. Finally,genetic studies (Groth 1993c, Parchman et al.2006) support the distinctiveness of Type 1:of the three distinct clusters of crossbill Types,two clusters have core breeding areas in theWest, and the other cluster includes onlyType 1. Parchman et al. (2006) found Type 1to be most genetically distinct.The Appalachians from southern New York

to northern Georgia, in particular those areasdominated by Red Spruce and in close prox-imity to Eastern White Pine, Eastern Hem-lock, and hard-coned pines, appear to formthe core zone of occurrence for Type 1 (Figure4). As Benkman (2007) first noted, RedSpruce is clearly one of the most importantconifers for Type 1, and so surveys for Type 1should be focused in July and August, whenRed Spruce is commonly used for nesting. Forthis Appalachian crossbill to survive, it is crit-ical that extensive areas of Red Spruce andother key conifers such as Eastern White Pineand Eastern Hemlock be maintained through-out the central and southern Appalachians;supplemental plantings of these coniferswould be useful as well. In the northern edgeof this Type’s core range, central-southernNew York, existing plantings of NorwaySpruce, Red Pine, European Larch, and otherconifers could be managed to benefit thecrossbills that nest here. Acid rain, logging,outbreaks of Hemlock Wooly Adelgid (Adelgestsugae) (Tingley et al. 2002), and global warm-ing, which alter forest composition, couldthreaten the existence of Type 1 Red Crossbill,which may prove, with further study, to be adistinct species. Observers interested in docu-menting Red Crossbill Types anywhere are en-couraged to study Groth’s (1993a) descrip-tions of calls and Young’s (2008a) primer onvocalizations, and to correspond withMatthew Young. It is worthwhile to publishany analyzed crossbill recordings in state andprovincial ornithological journals.Red Crossbills represent an ecological puz-

zle for biologists and birders alike, an oppor-tunity for pioneering field work for those in-clined to explore some of North America’s lit-tle-birded montane habitats. Every recordingadds an important piece to the puzzle, espe-cially when accompanied by notes on behav-ior and ecology, including tree species usedfor foraging and nesting. The conservation ofthese attractive finches will depend in largemeasure on our understanding their complexdistributions and ecological associations, andbirders can make critical contributions totheir conservation by recording crossbill callsand by reporting their findings.

AcknowledgmentsWe thank Craig Benkman, Jeffrey Groth, TomHahn, Ken Irwin, and Nathan Pieplow for dis-cussions of the Red Crossbill complex. JeffreyGroth has provided extensive assistance withanalysis of flight calls, and Craig Benkman hassupplied the authors with extensive detailsabout the natural history of the various RedCrossbill Types. The Macaulay Library of

Sounds at the Cornell Lab of Ornithology pro-vided recordings for analysis, and we thankCurator Greg Budney at the Macaulay Libraryfor extensive help in the field and in the li-brary. Finally, we thank Julie Siler for assis-tance in editing earlier versions of this paper.Finally, we thank Julie Siler and P. A. Buckleyfor extensive editorial assistance.

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