Identification and Distribution in California of the Sphyrapicus Varius

IDENTIFICATION AND DISTRIBUTION IN

CALIFORNIA OF THE SPHYRAPICUS VARIUS GROUP OF SAPSUCKERS

Pierre Devillers

INTRODUCTION

In his recent paper on avian hybridization,Short (1969) recommendedthat the three sapsuckers,Yellow-bellied Sphyrapicus varius,Red-naped S. nuchalis,and Red-breastedS. tuber be treatedas distinct species,thus opening a new chapter in a long controversy. S. tuber was describedas a new speciesin 1788 by Gmelin. Ridgway was the first to suggestits subordinationto S. variusin 1872 and againin 1873 and 1874. In his "Birdsof North andMiddle America" (1914) he returnedto treatingit as a distinctspecies. Meanwhile the A.O.U. Check-listhad retainedthe full speciesstatus in its three first editions(1886, 1895 and 1910), changingto a racialtreatment in the fourth edition, in contrastwith Ridgway'sown changeof mind. S. nuchalis,described by Baird in 1858, wassubsequently treated as a race of pariusby most authorities,starting with Couesin 1872 and Ridgwayin 1873, but Ridgwayincluded a note of warningin "Birds of North and Middle America",writing, "...I believethat it wouldbe betterto consider[nuchalis] as specificallydistinct from S. parius." The main issuewas alreadythe interpretationof the "intermediates" or "hybrids". Grinnell(1901), for instance,claimed to see"continuous intergradation"between S. pariusand S. tuber throughS. nuchalis,a view opposedby Ridgwaybut one whichpresumably weighed heavily in the later decisionof the A.O.U. Clearly,arguments over specimens couldnot leadanywhere, and careful study of the contactsbetween the formswas required, a needwhich was partially filled by Howell(1952). After studyingin detail the contactsbetween the Red-breastedand the Red-napedSapsuckers and summarizingthe very scantyinformation availableon the contactsbetween the Yellow-belliedSapsucker and the other forms, Howell supportedthe then currenttreatment of the A.O.U., consideringthe three formsas conspecific.Dickinson (1953),

Calif. Birds 1: 47-76, 1970 47 SAPSUCKER IDENTIFICATION & DISTRIBUTION

on the contrary, found convincingevidence for retainingruber as a distinctspecies in his analysisof BritishColumbia material. Apparently little further progresswas made in the field, but in 1969, Short, in the course of a general reassessmentof the taxonomic implications of hybridization,applied his criteria to Howell's information and thus reversed the latter's decision. A resultof the long treatmentof the three formsas races of one species,is the completelack of informationon identificationin field guidesand a consequentconfusion as to the statusof the various formsin severalareas. In California,for instance,there is a widespread belief that most birds are "intermediates",resulting in reluctanceof field observersto make positiveidentification of these forms,finally leadingto ignoranceof their comparativedistribution and abundance, and failureto recognizereal hybrids or ascertaintheir frequency. Even specimensare misidentified,sometimes in a manner that approaches the unbelievable. It seems warranted, therefore, to summarize the problemsrelated to the identificationof the three sapsuckers,their distribution,and the frequencyof hybrids. Throughout the paper S. varius,S. nuchalis, and S. ruber are consideredas distinctspecies, as suggestedby Short (op. cit.). This treatmentis alsofollowed by McCaskie,Devillets, Craig, Lyons, Cough- ran, and Craigin the CaliforniaChecklist (1970). This choicewill be furtherexplained in the paragraphdevoted to thecontacts between the species.

GENERAL DISTRIBUTION

As a backgroundto the discussion,an outline of the general distributionis presentedhere, condensedfrom Howell (1952), the A.O.U. Check-list(1957), Godfrey (1966), Griscomin Miller et al (1957), and variousother sources which are quotedwhere relevant. Designationsof the biomesare those of Shelford(1963), andare cap- italized. The Yellow-belliedSapsucker breeds in the southernhalf of the trans-continental Boreal Coniferous Forest belt and in the Northern TemperateDeciduous Forest of the easternUnited Statesand Canada.

48 SAPSUCKER IDENTIFICATION & DISTRIBUTION

In the West its rangeextends to southernYukon and includesnorth- eastern British Columbia (Peace River Valley) and westernAlberta (east of the Rockies). Within this regionit occursin deciduousor deciduous-coniferousstands, particularly where poplars and birches are important constituents. It winters throughoutthe southeastern United States and Central America, north to about 40 degrees latitude, west to central Oklahoma(Sutton, 1967), easternTexas, easternCoahuila, southern Durango, and southernSinaloa. It is of irregular occurrencein southern Arizona (Phillips, Marshall, and Monson,1964). The Red-naped Sapsuckeris characteristicof the Montane ConiferousForest regionof westernNorth America(excluding the Sierra Nevada). It breeds north to southeasternBritish Columbia and southwesternAlberta, west to the eastdope of the Cascadesand a few points on the east dope of the SierraNevada, south to central Arizona(Phillips et al, 1964) and the MogollonMountains of southern New Mexico(Hubbard, 1965). Outsidethe rangemapped by Howell, it has been found nestingin the Black Hills of South Dakota by W. and K. Eastman(Gammell and Huenecke,1954; Gammell, 1956; no supportingdetails). It breedsin forestscontaining aspen or aspen mixed with conifers,more rarelyin predominentlyconiferous forests. It wintersin southernCalifornia, most of Arizona(except the north- west),southern New Mexico,the wholeof BajaCalifornia, and the northwesternpart of the Mexicanmainland. The Red-breastedSapsucker has two well differentiatedraces. The northernrace, S. tubertuber, is practicallylimited to the Rainy WesternHemlock Forest of the northernPacific coast, occurring from southeasternAlaska to southernOregon, and extendingeast of the Cascadesat a few pointsin Oregonand Washington, aswell as inland in British Columbia to the Peace River Parklands. It winters in the coastal part of its range. The southernrace, S. tuber daggetti,breeds in a smallregion of the southernpart of the samebiome in northwestern Californiaas well asin the Cascadesof southernOregon, the Sierra Nevada,and the highermountains of southernCalifornia. It is a bird of aspen-ponderosapine association,except in its restrictedcoastal range. It wintersat lower elevationsthroughout California and in northwesternBaja California. It is evidentfrom this that the three species have different migrat- inghabits, varius being a longdistance migrant, nuchalis intermediate, and ruber a shortdistance migrant, the northernrace almost resident.

49 4

Red-naped SapsuckerS. nuchalis, presumed female, at nest hole in an aspen, westernWyoming, July 1969. Photoby HerbertClarke. 50 $! SAPSUCKER IDENTIFICATION & DISTRIBUTION

NATURE OF THE CONTACTS

This sectionis a summaryof the informationgathered by Howell; its purposeis to furtherexplain why the three formsare treatedas distinctspecies; in additionit will clarifyviews about prevalence and significanceof hybrids.

THE RACES OF R UBER

The two forms, tuber and daggetti, meet in southernOregon betweenKlamath Lake and the coast. Inland the replacementis rather abrupt, but in the coastalregion there is apparently progressive intergradationwhich justifies the treatmentof the two formsas conspecific. All intermediatescan thusbe expected,both in the contact areaand in the winter rangeof daggetti.

CONTACTS OF VARIUS WITH THE OTHER TWO FORMS

Next to nothingwas known about the possiblecontacts of the Yellow-belliedSapsucker with the other two speciesat the time of Howell'sstudies; he did not investigatethem himself, and, as far asI know, they have not yet been studied. This remainsthe main gap in our knowledgeof the complexand one whichwill haveto be filled beforeany reasonablycertain conclusions can be drawn. The Yellow- belliedand Red-napedSapsuckers are presumedto comein contactin westernAlberta but the regionhas not beencritically explored; it is further assumed,because of the scarcityof possiblehybrids in seriesof birdstaken on migrationor in winter,that interbreedingis very limited (Howelllists six possible hybrids). S. variusdefinitely comes in contact with S. tuber tuber in northern British Columbia, in the Peace River Parklands. Prior to Howell's study there had been two observations in that region,one (Swarth,1922) includingan apparentmixed pair observed(varius + variusx tuber) and a lone hybrid collected,the other(Cowan, 1939) a pair of typicaltuber breeding within eight feet and fifty feet, respectively,of two pairsof varius. I havebeen able to trace only two recent observations,both merely indicatingthe pre- senceof loneYellow-bellied Sapsuckers in the knownrange of the Red- breasted,north of PrinceGeorge (Rogers, 1968 and 1969). No hybrids are known from the migrationroutes, but they couldbe confusingly similarto nuchalisx tuberor nuchalisx daggettihybrids, or eventypical 52 SAPSUCKER IDENTIFICATION & DISTRIBUTION nuchalis,as indicatedby the specimentaken by Swarth,described by Howell.

CONTACTS OF NUCHALIS AND R UBER

The rangesof S. nuchalisand S. ruber daggetticome in contact alongthe easternslope of the Cascade-Sierraranges from southernOre- gon to central California. The overlap regionis alwaysvery narrow. The contact wasstudied in detail by Howell in ModocCounty, extreme northeasternCalifornia. He found the overlapregion to be about forty miles wide; at a point in the middle of this area,he found the following repartition for a sample of forty-two individuals: eight typical nuchalis,fourteen typical daggettiand twenty birds showing somedegree of intermediacy. (Of these,eleven are in the categories labeledas closeto one speciesbut with tracesof the other,which could includesome extreme variants of the pure forms in addition to true hybrids.) Thus, even with the most severecriterion, more than fifty per cent are typical birds. In central California, the contact seemsto take place almostwithout overlapand with very little interbreeding. In the SierraNevada daggetti occurs virtually alone;collect- ing nine miles west of Bentonproduced ten daggettiand one hybrid, in the SweetwaterMountains nine typicaldaggetti, one typicalnuchalis (Howell, op. cit.). Just to the east,in the White Mountains,nuchalis is the only form presentand is common(Miller and Russel,1956; McCaskie,pets. comm.). The samesituation prevails farther to the southeastin the Springand SheepRanges of Nevadawhere, however, Johnson(1965) recordedtwo hybrids,very closeto puredaggetti, one in each range;the SheepRange bird waspaired with a nuchalisfemale. An individual daggetti with traces of nuchalis characteristicswas collected on 16 September 1964 in the Charleston Mountains (Austinand Bradley, 1965). Still farthersoutheast, a loneS. r. daggetti, apparentlyunpaired, was taken in the HualapaiMountains (Arizona) in July 1959 (Coppa,1960); nuchalis was breeding in the vicinity. The northernrace of S. ruber,S. r. ruber, meetsS. nuchalisalong the Cascadesfrom southernOregon to centralBritish Columbia (with ruber to the west of nuchalis)and in the Cariboo Region of central interior BritishColumbia (with ruber to the north of nuchalis);Howell studied their contact at two points and in both casesfound almost no overlap,but insteadan abruptreplacement of one form by the other. At the Cascadelocation (where the replacementoccurred on either 53 SAPSUCKER IDENTIFICATION & DISTRIBUTION

sideof a burn 2.7 mileslong), he noted 10 pairsin the contactarea, only one of whichwas mixed (female nuchalis with maletuber showing slighttraces of hybridization). At the Caribooregion location, be- tweenQuesnel and WilliamsLake, he notedcomplete replacement of one form by the other over 1.5 miles(except for onetuber andone intermediatefound pairedwith nuchalisin the rangeof the latter, amongfive pairsof purenuchalis). In the replacementzone he found two pairsof ruber, two pairsof nuchalis,one pair of intermediates, andone pair involvingan intermediateand a nuchalis. Recently a pair of apparentlypure nuchaliswas found nesting thirty milesnorth of Quesnel,well to the north of the contactstudied by Howelland within the rangeof ruber(Rogers, 1967). Together withthe recent observations of varius in thePrince George region, this bringsthe threespecies within a fairlylimited area.

CONCLUSIONS

Short (op. cit.) has proposedthat contactareas be classified either as "hybrid zones"if only hybridsoccur in the areaof hybridization, or as "zonesof overlapand hybridization"if both parental forms are presentin the zone, as well as numeroushybrids. In the latter case, the parental forms are actually sympatric, and Short recommendstreating them taxonomicallyas species.The numberof parentalphenotypes that mustbe presentto precludethe possibility of their beingthe resultof recombinationis arbitrarilyfixed by him at not lessthan five per centof the population. It is clearfrom the previousdiscussion that the contactsbetween S. ruberand S. nuchalisboth qualifyas "zonesof overlapand hybridization",justifying their treatmentas distinctspecies. Indeed,the contactbetween ruber and nuchalisinvolves very few hybrids, while that betweendaggetti and nuchalis involves about fifty percent hybrids at most, well below the threshholdproposed by Short. The same appliesto the overlapbetween varius and ruber, as far aswe know. On the other hand,the criterioncannot be appliedto the varius-nuchalis relationship.The specimensfrom the winteringarea constitute only indirectand very poor evidencefor limitedinterbreeding. A far more convincingargument for holdingthem asdistinct species is foundin the juvenileplumage and the timing of the moult. In thesecharacters the two forms certainlydo not seemmore closelyrelated than nuchalis 54 SAPSUCKER IDENTIFICATION & DISTRIBUTION

and tuber are. Let us still emphasize,however, the needfor a study of the presumedoverlap area.

IDENTIFICATION

From the foregoingit is clearthat one shouldnot expecta high proportionof hybridson the wintergrounds,and thereforethe idea that most sapsuckersare intermediateshould certainly be discarded. It remainstrue that the possibilityof hybridsconsiderably complicates certain aspectsof the identificationproblem. Conversely,recording possiblehybrids away from their breedinggrounds can be very interesting in connectionwith the studyof the migrationsof the species,and carefulnotes should be madeof any bird presumedto be intermediate. Descriptionsof all the formscan be found in Ridgway(1914) and Howell (1952); Bent (1939) discussesthe juvenileplumages and the progressto maturity. The discussionof identificationin this sectionis basedon their accounts,on personalfield notes, andparticu- larly on examinationof the collectionof the SanDiego Natural His- tory Museum(hereafter referred to as SDNHM), consistingof 21 varius, 102 nuchalis, and 62 tuber.

ADULTS

Adult Red-breastedSapsuckers (males and femalesalike)are separatedat first glance(except from hybrids!)by their completered hood, includinghead, nape, and breast(fig. 11 & 12). It shouldbe noted, however,that the dark and pale head markingsof the other formsremain visible as an underlyingpattern in S. r. daggetn'and, to a much lesserextent, in S. r. tuber. Most field guides depict S. r. tuber, which accountsfor the falseimpression that the daggem' seenare "intermediates".In fact, a longwhite or whitishmoustache, black lores,and a white postocularspot are normal featuresof S. r. daggetti; this race has as much white on the back as S. nuchalis,or slightlyless. S. r. tuberdiffers from S. r. daggetti(see fig. 11) by its deeperred and usuallymore extensivehood with the headpattern very obscure,a blackerback with the white reducedto two very narrow stripes,broken and often tinged with yellow, and deeper yellow underparts.However, the two racesdo not normallyoccur together,and they are too similarto allow reliablefield identification of possiblestrays, unless the bird is handled. 55 rt

FIGURES 1 and 2. Male Yellow-bellied Sapsuckers(left in each photograph) and Red-naped Sapsuckers(right in each photograph). Note the extent of red on the throat; in nuchalis, the black bordering line is interrupted, in variusit is not. Also compare the color of the nape: white in varius, red in nuchalis. The greater amount of white on the back ofvarius is also visible. Specimenphotographs by Alan M. Craig

The separationof variusand nuchalisis far more delicate,and in some casesfeasible only under extremely favorableconditions. When- ever possible,any critical bird shouldbe trapped and examinedin the hand. Both specieshave the samebasic pattern: a red crownbordered by black;black auricularscontinuing in a blackband on the sidesof the neck; a black nape interruptedby a white or red area; a red or white throat bordered by black, which also forms a broad breast patch; white underpartstinged with yellow;barred flanks; a black back and black scapularswith a greateror lesseradmixture of white or whitish,either forming two distinctstripes or coveringthe entireback; black wingsbarred with white on the flight feathers,and with a large longitudinalwhite patch alongthe anteriorpart; a white rump;and a blacktail with whitebars and spots. 56 FIGURES 3 and 4. Female Yellow-bellied Sapsuckers(left in each photograph) and Red-naped Sapsuckers(right in each photograph). Note the white throat and chin of the former, while the latter has a red throat and a white chin. Again, the white nape of varius and the red nape of nuchalis can be seen; although the female varius has more white on the back than the female nuchalis, both specimensshow more white than the male nuchalisin fig. 2.

The most important characterin separatingthe two species,irre- spectiveof the sex of the bird, is the color of the nape(fig. 2 & 4). Yellow-belliedSapsuckers have the black nape line (the line that joins the posterior crown to the upper back) interrupted by a white or brownish-white area connected with the postocular stripe. In Red- naped Sapsuckersthe correspondingarea is red. Unfortunately,it is possiblethat this singlecharacter is not always reliable. I have not found any individualin the SDNHM that did not show it, but Howell, who has examineda larger number of specimens,claims that the nape of variusis "rarely tingedlightly with red" and, worse,that for nuchalis "in very rare instancesthe red of the nape is lacking". Besides,the red coloration is confined to the feather tips and could conceivably disappearthrough wear (complete moult in late summerand fall, partial moult about the head and throat early in spring- Bent, 1939). 57 SAPSUCKER IDENTIFICATION & DISTRIBUTION

Furthermore,even a small degreeof hybridismcould lead to the mod- ification of such a single character. For all these reasons,it is not possibleto rely entirely on the color of the nape for positiveidentification, and further supportingcharacters will have to be sought. Male nuchaliscan be fairly easily separatedby the following additionalcharacters: The throat is entirely red; the red coversthe posteriorpart of the black malarstrip, thusinterrupting it and actually comingin contact with the white of the cheek; the red also extends over the upper part of the breastpatch (fig. 1); often the auricular region is tinged with red. The white on the back is restrictedto two definite stripesconverging posteriorly; these stripes are narrowerthan those of varius(the stripesare chaindike,the white line beingin- terrupted by black bars; however, in male nuchalis the individual white elementstend to be long andnarrow, looking like "drops"while on thosevarius that show a "two striped"effect, the individualele- ments are short and broad, producinga ladder-likeappearance); the whiteis usuallypure or tingedwith yellowish(fig. 2). At the other extreme,female varius (fig. 3) areeasily determined by their entirely white throat, without any red, borderedby a black frame. Some individuals lack red on the crown also. Male varius have a solid red throat, and differ from male nuchalis primarilyby the uninterrruptedblack frame that bordersthe throat, so that the red does not come in contact with the white (fig. 1). Additionally,they have more white on the back;either the white spotting coversthe back almostuniformly, or, if stripesare formed,they arebroad and havethe ladderappearance explained above (fig. 2); the white, at least in winter, is usually tinged with goldenor bronzy buff; it is slightly different from the color of nuchaliswhen the two are compareddirectly. Most female nuchalishave a white chin and a red throat (fig. 3), or sometimesa white chin andupper throat with only the lower throat red; this alone is sufficientto identify them. Unfortunately, a certain numberof birds showan almostentirely red chin and throat, and they may be impossibleto separatein the field from male Yellow-bellied Sapsuckersexcept by the colorof the nape. Sucha bird is shownin fig. 5 togetherwith a male varius. Among16 adult and 14 subadult (i.e. brown breasted)nuchalis individuals labeled as female in the SDNI-IMcollection, 8 (3 adult and 5 subadult)have enough red in the throat and chin for thoseparts to be calledentirely red in the field; 3 of those (1 adult, 2 subadult)have interrupted black framesand would simply passfor male nuchalis(which they might well be!), 58 FIGURE 5. This photograph illustrates the difficulty of separatingsome female Red-naped from male Yellow-bellied Sapsuckers. This particular female nuchalis (below) has almost as red a throat as the male varius (above), and also has an un- interrupted black malar strip; note, however, that the former showsa little whitish near the base of the bill. but 5 (2 adult, 3 subadult)have completeframes and could be called male variusin the field except for their red napes. Here lies,as already pointed out by Phillipsand Marshall(1964), the main pitfall in field identification of S. nuchalis and S. varius. For those birds with a complete black frame around a solid red throat, the following guidelines are suggested.Male variuswill have a truly uniform red throat, while, for female nuchalis, an admixture of white feathers will usually be noted, particularly toward the chin, if the bird can be examined in the hand or at very closerange. Vaguswill in generalhave more white on the back, the pattern being indicated above; most female nuchalis have the same type of pattern as male nuchalis(narrow chain-like stripes),but someshow the ladder-likestripes of variusand a very few do not even show any band pattern (fig. 4). Finally, it seemsto me somewhatunlikely (?) that the red nape would be lacking in sucha heavily pigmented female nuchalis, and it is not at all certain that the combinationof fully red throat and white nape doesexist in pure nuchalis females.

59 SAPSUCKER IDENTIFICATION & DISTRIBUTION

Any birdpresenting what seems to be a combinationof characters betweenthe two speciesshould be very carefullydescribed and, if possible,photographed since very few possiblehybrids are known. As an illustrationto this discussion,color drawingscan be found in variousfield guides. The Red-breastedSapsucker is very satisfac- torily shownby Crosbyin Godfrey(1966), by Eckelberryin Pough (1957),and by Peterson(1961), but all havechosen the race ruber for a model(as apparently did Singerin Robbinset al, 1966). Bothsexes of the Yellow-belliedSapsucker are well representedby Crosbyin Godfrey,although the blackframe around the throatis perhapsnor- mally broaderthan shown,and by L. AgassizFuertes in Forbushand May (1953); a goodpicture of a male is givenby Singerin Robbins et al. Satisfactorydrawings of Red-napedSapsuckers are not frequent, but Eckelberryshows a malein Pough;however, the red of the throat is more extensive than shown.

IMMATURES

The juvenileplumage of all speciesis strikinglydifferent from the adult plumage,appearing mostly brown, with the redareaslacking, the white areas much obscured,the black head and breast pattern replacedby brown. The tail and wingsare similarto thoseof adults. This plumageis replacedby a slow progressivemoult. The three speciesare very similarto eachother at that stageand their identification requiresgreat care. Since nuchalisis somewhatintermediate in appearancebetween varius and ruber, we will discusssuccessively the nuchalis-variusand ruber-nuchalis identification problems. The timing, sequence,and mannerof the moult is of decisive importancein the identificationof the first two species.Howell hints that the progressmight be faster in nuchaliswhen he writes, "Moult is apparentlyas in S. v. varius,but adult plumageis sometimesattained by late fall and always by early springat the latest." The varius material in the SDNHM is insufficientto draw definitiveconclusions, but immatureplumaged birds have been collected in September(1), October(5), December(1), February(1), and on 15 March(1); none has a uniformly red crown, and the March bird, a male, still has very little red in the throat. The nuchalis material is much more extensive. Twelvebirds are in almostcomplete juvenile plumage; they weretaken between 26 July and 2 September;four of them have partially red

60 SAPSUCKER IDENTIFICATION & DISTRIBUTION crownsand some red on thethroat (2 females:26 August,2 September; 2 males: 18 and 20 August);two (males,6 August)have some red on the throat but none on the crown. Two birds collected on 3 and 30 August are intermediate, already showing a lot of the adult pattern, including a red nape, as well as some red on the crown and the throat. The other immatures(22 birds)show a completelyadult- like plumageexcept for a brown, scallopedbreast, and sometimes somebrown in the malarstripe; they were collectedin August(1), September(6), October (10), and early November(5). Only four specimensshowing signs of immaturity were collectedat a later date; two of them havea lot of black in the brownbreast (male, 16 January and female,28 December);a 5 Februaryfemale might be hybrid, asis almost certainly the fourth bird, collected on the same date at the sameplace. Thus, excepton the breedinggrounds, i.mmature nuchalis can be expectedto showmuch of the adultplumage, particularly the red areas, so that their identification is not different from that of adults; indeed, all the birdswe haveexamined, except the twelvein nearlyfull juvenile plumage,show the red nape. Confusingfemales have already been included in the previoussection under the label subadult. On the contrary, immaturevarius are much slowerin developing,and individuals can be seenduring most of the fall and winter with little or no red in the crown and throat; it is useful to discusstheir charactersin detail. At any stage,the pattern of the crown is the most diagnostic feature of yaHus. At first the entire crown is dark brown, dotted with fine, sharp,very conspicuous,pale brown to goldenor whitish spots,sometimes slightly elongated (fig. 6 & 8); often there is alsoa scatteringof black spots. Later, scatteredred feathersappear ran- domly throughoutthe crown, addingto the variegatedeffect; the red featherscover more and moreof the crown,but the light dotting remainsapparent until the crown is solidly red. Conversely,juvenile nuchalishas a uniform dark brown crown,slightly darker than yaHus, sometimeswith faint, paler brown spots,but rather diffuse and in- conspicuous(fig. 8); often thereis a uniformred suffusion,particularly near the bill and on the forehead. Soon, it seemsthat a solid red patch developsfrom the same area and includesprogressively the wholecrown; some of our birdsshow a partiallyred crown: the red region coversonly the anterior crown, but there are no isolated red feathersappearing elsewhere.

61 FIGURE 6. Three immature Yellow-bellied Sapsuckers. Note the spotted crown and spangled back. The bird in the center is the California specimen (lower Colorado, 18 December 1938).

The light stripes of the head pattern are usually broader in vagusthan in nuchalis,and lesssharply defined, giving a morefrosty appearance;this is very difficult to evaluateand somewhatsubjective. The supposeddarker chin and throat of nuchalis(Howell) does not hold. (fig. 7). Almost all our varius have a very yellow belly and the breast is yellowishbuff-brown with heavy, sharp,dark brown scalloping. Ju- venile nuchalis have a more uniform breast, brown with fine, indistinct scalloping;the belly is much less yellow. This correspondsto the descriptionsof Ridgway and Howell, but it probably represents different stagesof plumage. One varius in the collection,#22691 collectedin Georgiain October,has hardly any yellow on the belly and an indistinctly scallopedbreast; it is indistinguishablein that respect from juvenile nuchalisand may be representativeof juvenile varius. Also, many nuchalis that have progressedbeyond the complete juvenile plumagehave the belly as yellow and the breastas distinctly scallopedas varius;note, however,that in that case they have fully developedred areas. 62 FIGURES 7 and 8. Two December immature Yellow-bellied Sapsuckers(two lower birds in each photograph) are compared with an August juvenile Red- naped Sapsucker(upper bird in each photograph). The California varius is in the center. Note the uniform brown cap of nuchalis, and its relatively unpatterned back. The heavy scalloping of the breast of varius can be seen. It is evident in these figures as well as in fig. 6 that the California bird has the charactersof earius. In addition, the new white feathers of the throat of this bird can be seen in fig. 7. I

FIGURES 9 and 10. Augustjuvenile Red-naped Sapsucker (left in eachphoto- graph) and Red-breastedSapsucker (right in each photograph). The latter has obscureface stripingand a darker, more uniform breast. The specimenshown representsS. tuber daggetti.

The backs of all our immature varius are extremely striking, being entirely spangledwith deep goldenor very deep buff offset by black (fig. 6 & 8). The materialavailable does not permitjudging whetherthe juvenilebird is similar,but Bent describesa youngbird, not fully grown,taken 25 July asboldly spotted with grayishor yellowish white on black. The back of juvenilenuchalis is a dull dark brown to black with white spotting,obscured on the upper back, and not tinged with buff or yellow, exceptsometimes on the lower part of the stripes(fig. 8): in first winterplumage, when the adult type back is acquired,it is not as extensivelyspangled nor as deeplycolored as in varius;again in that case,the red areasare present. Accordingto Howell an occasionalS. nuchalisis paleenough to be indistinguishablefrom a dark S. varius. However,we think that the patternof the crown,at least,should make identification possible at any stageof plumage. 64 SAPSUCKER IDENTIFICATION & DISTRIBUTION

JuvenileRed-naped and Red-breastedSapsuckers (fig. 9 & 10) are alsofairly similar. Ruber hasa darkerhead and breast, more sooty, and its breast is even more uniform, almostlacking any scalloping; better, the stripingof the headof ruber is muchobscured, reduced to a whitish moustacheand frequently a dull white postocularspot (in daggettt'). Usuallythe pileurn,throat, and breastare washedwith reddish,in whichcase identification is very easy. At any rate, the timing of the moult of ruber is very similarto that of nuchalis,or evenfaster, so that the adult plumagecan usuallybe recognizedat a very early age,simplifying the identificationconsiderably. Birds away from the breedinggrounds should pose no problems. Very few colordrawings of immaturesapsuckers can be found in field guides;the bird shownby Petersoncorresponds somewhat to nuchalis,while Singer's(in Robbinset al) is a combinationof varius and nuchalis.

DISTRIBUTION IN CALIFORNIA AND BAJA CALIFORNIA

The distribution of the different forms within the two states is still imperfectlyknown, becauseof the lack of specificdata from field observers,and the resultingnecessity to rely on collectedmaterial whichis by naturea very smalland incompletesample of the popula- tions involved. This section is based mainly on the distributional checklistsof Grinnell (1928) and Grinnell and Miller (1944), the studiesof Howell(1952), andan examinationof the SDNHMcollection. The latter involvedthe reassessmentof severalspecimens. All the specimensof the collectionwere discussed with JeanT. Craig,and she concurredwith the identification of the critical individuals,namely S. varius(#31656), S. nuchalisx S. varius(#14286) andS. r. ruberx S. nuchalis(#31652) from Bard,along the lowerColorado, S. r. ruber from San DiegoCounty (p30061) andthe varioushybrids S. ruberx S. nuchalis mentioned later. Our determinationswere made by com- parison with the local material only. The most important specimens (p31656, #30061, #31652) were examinedby Alan M. Craig who agreedwith their interpretation. Finally, #31656 and #30061 were sentto Dr. Allan R. Phillipswho very kindly acceptedto examinethem. The Red-breastedSapsucker breeds in the coastaldistrict south to MendocinoCounty, in the entire SierraNevada and in the connect- ing mountainousarea in the extreme northern part of the state (extendingeast to the WarnerMountains). Isolatedpopulations are found on the highestmountains of southernCalifornia, Mt. Pinos, 65 SAPSUCKER IDENTIFICATION & DISTRIBUTION

San Gabriel, San Bernardinoand San Jacinto Mountains,and also on Mt. Palomar. As far as we know, the fact that the bird breeds on Palomarhas not been published before. Arthur G. Morley(pets. comm.) has recordsof the speciesin PalomarState Park throughoutthe summer, from May (March in 1970) to September.His recordsdate back to 1957. He obtainedpositive evidence of nestingtwice; he observed a bird feeding youngin an alderon 26 June1966 (altitude4600 feet) and he examineda fledglingfound in a campgroundon 13 July 1970. All this information was generouslysupplied by Mr. Morley from his personalnotes, togetherwith ample detailssupporting the identification. I have seenthe species,myself, on Palomar,but at a slightlydifferent location from that of A. G. Morley'sobservations, on 14 April 1968. In winter, it occursthroughout the state but only very rarely in the southeast. Grinnelland Miller (op. cit.) mention only one recordfor the Mojaveand ColoradoDeserts. In BajaCalif- ornia it is recordedonly from the westernslope, south to Rosario. San Diego County and Baja Californiaspecimens in the SDNHM are from September20 to February 17. Local sight recordsextend to earlyMarch (PD). The only race included in the avifaunasof the statesby Grinnell (1928) and Grinnelland Miller (1944) is daggetti.AsHowell indicated, Grinnell somewhatarbitrarily assigned all northernCalifornia breeders to this race;actually, a line cannotbe drawnto separateprecisely the rangesof the two races,and the northernpart of the state belongs to the region of intergradation. Birds referrableto S. r. ruber can, however,occur in winter. A specimentaken five miles northeastof Lakeside,near San Diego,on 9 November1957 (SDNHM #30061) is exactly similar to the ruber material in the collection, which is entirelyfrom Oregon.The red coloris of the samedepth and intensity, the red hood as extensive,and the back is identical,very black with greatlyreduced and very yellow stripes. There areno whiteedgings to the outer tail feathers. The specimenshows a little more white than averageon the extremeupper back. We feel that it belongsto the southernpopulation of ruber, showingintergradation with daggetti. Dr. Phillips(in litt.) also assignsit to ruber but remarksthat he, as well, could compareit only with Oregonmaterial, and that the bird may representthe middle part of a cline. He addsthat he has two probablemigrants, taken in Humboldt County in Octoberand Febru- ary, which are still darkerred and may representbirds from British Columbia.The SanDiego bird is shownin fig. 11, betweenspecimens of ruber and daggetti. 66 FIGURE 11. Red-breasted Sapsuckers. The lower specimen is typical of daggetti and the upper one of ruber (Oregon population). Note on the latter the lack of white on the back and on the remiges. The bird in the center is from San Diego County and approachesruber.

The Red-napedSapsucker breeds in the WarnerMountains where it is, by far, the dominant species. It also occurs,mixed with the Red-breastedand hybridizingwith it, in neighboringareas to the west (Howell, 1952). Farther south it is a commonbreeder in the White Mountains(Miller and Russel,1956; McCaskie,pets. comm.). A few pure birds might breed in the SweetwaterMountains and adjacent areasof the eastslope of the SierraNevada (Howell, 1952). It winters along the lower Colorado,in the Mojave and Coloradodeserts, the coastalregion south of about35 ø of latitude,and sparingly over the entire peninsulaof Baja California. It is everywherethe only or the dominant form, except on the Pacific slope of southwesternCalif- ornia, whereit is rarerthan daggetti. SDNHM specimensfrom southern California or Baja California have been taken between early October and early February;local sight recordsextend to early March (PD) There is a scatteringof winter recordsfrom the areawest of the Sierran divide and north of the 35th parallel. Those listed by Grinnell and Miller includeone from ShastaCounty, five from the westslope of the Sierra Nevada and four from the coastal district between Marin and SantaCruz Counties(some of thosemay pertainto migrants).More 67 FIGURE 12. A hybrid sapsucker, taken along the lower Colorado (center) is compared to a Red-naped Sapsucker (below) and a Red-breasted Sapsucker of the ruber race (above), the presumedparental forms. Note the great reduction of white on the back of the hybrid, which points to the black-backedruber rather than to daggetti. recently, winter records have been published(without supporting details)from the San FranciscoBay area(South San Jose,20 January 1966, reportedby D. D. McLean;Chase and Chandik1966)and, more remarkably,from MendocinoCounty (Westport,6 and 20 December 1954, seenbyR. Coy; Cogswelland Pray, 1955). Hybrids between the two specieshave been taken in summerin the overlap region, as mentioned earlier. The record of a hybrid, feedingyoung in the San Gabriel Mountains,far outsidethe contact area(McCaskie, 1964) shouldbe disregarded(G. S. Suffel,pets. comm.). Wintering intermediatesbetween nuchalis and daggetti are mentioned by Howell from "southern California" and Santa Cruz Island;he refers a specimenfrom CrescentCity (northern coast),29 November1915, to nuchalis x ruber ruber. In the SDNHM collection,we recognize as daggettix nuchalishybrids, a bird from Dehesa,San DiegoCounty (#31644, male, 15 February1919), and one from the PintaMountains, Kern County(#11719, male,4 November1907). An individualtaken near Lakeside,San Diego(#30058, 10 October 1957) is a hybrid of 68 SAPSUCKER IDENTIFICATION & DISTRIBUTION nuchaliswith either ruber or daggetti. An intermediatefrom the lower Coloradois, in our opinion,a ruber ruber x nuchalishybrid; the white spottingof the back is reducedto verylittle (•31652, female, vicinity of Bard, 31 December1916). It is shownin figure 12 between typical examplesof nuchalisand r. ruber. A secondhybrid is more difficultto assess,but mayhave the sameorigin (•31661, female,23 October 1924, one mile north of Potholes). A few other individuals of either nuchalis or daggetti show "traces" of the other form but are very difficult to judge since they may be extreme variants. The Yellow-belliedSapsucker is not known to occurregularly in Californiaor Baja California. One occurrencehas been reportedin the state: Pasadena,19 July 1950 (Davis& Howell, 1951). The record wasnot acceptedby McCasideand coworkers(1970), becauseit per- tained to a mummifiedspecimen the originof whichclearly remains in doubt. The bird is an adult female, with a few red feathers in the throatindicating a probabledegree ofhybridism. The speciescan, however, be expectedin the two states, at least occasionally,since it has been recorded irregularly in the Tucsonarea of Arizona (Phillipset al, 1964, mentionits occurrence in seven different winters, beginningin 1940, with severalin 1952- 53), and, at leastcasually, to the Arizona bank of the lower Colorado (Phillipset al, op. cit.). In the SDNHMcollection, specimen #31656, an immaturefemale collected two miles north of Bard on the west side of the Colorado near Yuma, on 18 December 1938, by LaurenceM. Huey, showsthe charactersof typical varius. The bird is illustratedin figure 6 with two Yellow-belliedSapsuckers in similarplumage and in figures7 and 8 with a Yellow-belliedand a juvenileRed-naped Sapsucker. In addition, the followingdescription was made of the specimen: Chin and upper throat white. Dark brown moustaches. Lower throat and upper breast gray-brown. Middle breast heavily scallopedwith dark brown on light brown. Belly and undertail- coverts pale yellow. Flanks brown, scalloped with blackish. Cheek brown and black. Whitish stripe behind eye. Crown dark brown, with fine, sharp, pale brown spotting, four red feathers and some black spots towards the rear. Upper back mostly goldenbuffy with black spotting. Lower back showingtwo broad golden buffy "ladders" with a narrow black line separatingthem. White band on closedwing (coverts). Primariesblack, barred with white. Tertials broadly edgedwith white. Tail black; the inner webs of the middle pair of rectrices are barred black and white; the lateralmost rectrices have white dots on both webs. The spottedcrown with a few scatteredred feathersis charac- teristic of varius;the colorationand pattern of the back and of the 69 SAPSUCKER IDENTIFICATION & DISTRIBUTION underpartsfall well within the limitsof variationof that form. The lack of adult charactersaround the head is very unlikely for nuchalisat the late date this bird was collected(Dec. 18). Dr. Phillipscompared this individual with his material and concurs with the identification. He writes(in litt.) that "thisbird is a perfectlytypical [Sphyrapicus varius]varius, and a goodbasis for its inclusionin the Californialist" (Dr. Phillipsdoes not subscribeto recognizingthree speciesof varius without further field evidence). He alsopoints out that the bird has severalnew white feathersin the lower throat, includingone with a black terminal spot; this region is alwaysred in nuchalis. Those feathers,particularly the black tipped one, are visibleon the photograph(fig. 7). A female in the SDNHM collection,•14286, taken three miles north of Bard, on 5 February 1931, by L. M. Huey, hasa white throat except for red patchesin each lower corner, widely separated. The nape has a fair admixture of white (to what extent is difficult to judge on a specimen),the white stripesof the head are very broad, and, as mentionedbefore, the bird has a completebrown breast at the late date of 5 February. We considerthis bird almostcertainly a hybrid nuchalis x varius. A secondfemale, •14285, taken on the sameday at the same place, cannot be positivelyassigned but could also be of mixed ancestry. The red of the throat is more limited than usual,being restrictedto a narrow band on the lower quarterof the throat. The breast is brown with little black. Finally, for the sakeof completeness,the followingobservation from the San Diego area is related. The main reasonto presentit, is that only an accumulationof material,pertaining to probableor certain typical birds, and particularlyto birds that exhibit possiblehybrid characters,will permit drawinguseful conclusions. A very few records will not throw muchlight on the statusof the form within our bound- aries,because of the complexityof a situationthat may involveun- recognizablehybrids. In addition,this recordwill illustratesome of the difficulties involved in field identification. On 20 December1969 at Imperial Beach,just south of San Diego,Xenia Devilletslocated a sapsuckerand drew my attentionto it. The woodpeckerwas working low on the trunk of a eucalyptustree with its backto the observers.It resembleda Red-naped Sapsucker, but, at firstinspection, the completelack of red on the napewas very striking;suspecting that the bird couldbe a Yellow-belliedSapsucker, I took the followingdescription of it: 70 SAPSUCKER IDENTIFICATION & DISTRIBUTION

Forehead and crown bright red bordered with black; black stripe running down the middle of the nape interrupted by a very narrow white gap just below the crown. Black stripe througheye to the sidesof the neck. Chin and throat brightred borderedby a broad black band. Rest of headand neck whitish. Upper breast brownish;rest of underpartsyellowish; flanks marked with dark gray "V"s on a yellowishground color. Center of the back, black. On either side,a broadband, buff or palebrown, barredwith black. Coverts black with a broad white band near the edge of the wing. Secondariesblack with largewhite dots. Primariesblack with fine terminalwhite edges. Rump white. Tail black. The bird was kept under observationfor about half an hour as it worked in. a smallgroup of eucalyptustrees located in an old over- grown garden. The general area is residential with eucalyptus- borderedlanes, the treesbearing numerous marks of sapsuckerpresence. Severalattempts at relocatingthe bird later both by the writer andby other observersfailed. Long,careful scrutiny at lessthan thirty feet, with 7x50 binoculars,and in good light (bird at eye-level),showed beyondany doubt that there wasnot a traceof red on the napeand that the narrowinterruption in the blackstripe was white. Consider- able attention was also given to the chin in order to eliminatethe possibilityof a femalenucttalis, and no whitefeather could be found. We are unfortunatelyconfronted with a bird with a full red throat and a completeblack frame, which is the most difficult type. However,in additionto the very significantwhite nape,the complete lack of white in the throat and the wideness of the black frame are charactersof male varius. The patternof the back with very broadand ladder-likepale stripesis alsoindicative, although it is not extremeand could easily be matchedby a female nuchalis. In addition, the buff colorationis of variustype. A completelybrown breast at this late date is unlikely in nuchalis;on the other hand, it is early for variusto have completered areason crown and throat. The evidenceseems to point towardsa male Yellow-belliedSapsucker in transitionalplumage, but the possibilityof a hybridor of an extremevariant nuchalis (female) cannotbe entirelyeliminated. I hope thesenotes will encourageobservers to studysapsuckers criti- cally, particularlyalong the lowerColorado and in the SanDiego area; I feel confidentthe near future will producemore recordsof variu•

"VAGRANCY" IN THE SPHYRAPICUS FARIUS COMPLEX

The considerationof "extralimital" recordsin this groupis particularly interesting,because of their connectionwith the hybridi- 71 SAPSUCKER IDENTIFICATION & DISTRIBUTION

zation phenomenon.Four formswith very different migratoryhabits comein contactand hybridize. Sincethe migrationmechanisms are in all probabilityunder ge•aetic control, it is to be expectedthat they will be stronglyaffected by hybridization. Hybrid individualswill in- herit the migratorybehavior of eitherof the parentspecies, or perhaps somecombination of both, if sucha thing is possible. We can thus expect to find hybrids in the winter rangeof either of the parent species,and this could, of course,include birds which are pheno- typically (at leastas far as externalappearance is concerned)identical to the other parent species,although genetically of mixed ancestry. Suchbirds would appearas "pure" individualshaving straggled from their normalrange. Manyof the extralimitaloccurrences of sapsuckers can probablybe explainedby sucha mechanism.One can arguethat innumerable"vagrant" records also exist in speciesthat do not hybridize in thismanner. However, those involve mostly birds on migration which can be assumedto havedefective orientation mechanisms. They are not usuallyfound winteringmuch closerto or much farther from the breedingrange of the speciesthan normalindividuals. The "vagrant" sapsuckers,on the contrary,are mostly seenin winter, in areas which are well outsidethe winter rangeof the speciesthey resemble, but insidethat of anotherform. The journeyinvolved may be much longer,or much shorter,than that normallyperformed by the species. It is notable,furthermore, that amongthose "extralimital" individuals there appearsa numberof clearhybrids. S. r. tuber, an almost sedentaryform, is recordedfrom Arizona (threerecords, October to February,Phillips, etal, 1964);in addition, an "occasionalintermediate towards nuchalis has been taken" (Phillips, etal, op. cit.). From southernCalifornia there are the SanDiego bird (p30061), approachingtuber, and the lowerColorado tuber x nuchalis (p31652and possibly p31661) mentioned before. S. r. daggetti,a short distancemigrant, has straggledto Arizona, (two records,Sacaton, 9 February 1910, and lower Colorado, 23 January1953 - Phillipsetal, 1964); a bird identifiedas a hybrid daggettix nuchaliswas collected in Albuquerque,New Mexico,on 13 March 1962 (Niles, 1966). S. nuchalishas been found in Guatemala,according to Griscom (1932), hundredsof milessouth of its normalrange, but in the rangeof yaHus;I have not seenthe originalSalvin and Godman record,also quotedby the A.O.U. and haveno ideaof its validity. Recordsfrom San Luis Potosiand Yucatan are mentionedin passingby Howell (1953), but I do not know the basisof his statement,and the records 72 SAPSUCKER IDENTIFICATION & DISTRIBUTION havenot beenincluded in the A.O.U. checklist(1957), or in the Mexi- can Checklistof Miller et al. (1957) A scatteringof recordsfrom California,west of the Sierrandivide and north of the 35th parallel, are north of the normalwintering range, but in the rangeof S. ruber. Particularlysignificant is the Westportrecord (Cogswell and Pray, 1955). S. vagusis irregularlyfound in Arizonaand probably to southern California. It is difficult to decide whether this constitutes the north- westernlimit of the normalwinter range(the bird havingbeen over- lookedin northwesternMexico), or 'whetherthe rangeas outlinedby Howell is correct, in which case all the Arizona-Californiarecords couldpertain to a geneticallymixed stock. It shouldbe notedthat suchbirds would not have to be scatteredthroughout the wintering rangeof the otherparent species, since they couldparallel the habitsof a localpopulation, which might occupy a limitedportion of the wintering range. The large number of birds involved in the Arizona records(in the winter of 1952-53, in the Tucsonarea, variusout- numberednuchalis, G. Monson,1953) however,supports the ideathat the regionis within the normalwintering range of the Yellow-bellied Sapsucker. Certainly,a very interestingpattern could be revealedby careful observationof "extralimital"sapsuckers and particularlyof probable hybridson their winteringgrounds. As pointedout by Howell,those may be particularlydifficult to identify, sincemany could be matched by extremetypes of individualvariation within the typicalpopulation.

ACKNOWLEDGEMENTS

I am greatlyindebted to SuzanneI. Bondfor permissionto study the collectionof the SDNHM, and for assistancein that study,including the sendingof specimens.I am obligedto Dr. Allan R. Phillipsfor his kindnessin examiningthose specimens and his extremelyuseful comments. Alan M. Craig generouslyaccepted to illustratethe paper and examinedthe critical specimens.I am particularlygrateful to Jean T. Craig for her collaborationin analyzingthe entire specimen collection,fruitful discussionson identificationand invaluablehelp in bringingthe manuscriptto its final form.

73 SAPSUCKER IDENTIFICATION & DISTRIBUTION

SUMMARY

The generaldistribution of the Yellow-belliedSapsucker $phy- rapicusvarius, Red-naped Sapsucker $. nuchalisand Red-breastedSap- suckerS. ruberis briefly outlined. The informationgathered by Howell about their contact and hybridization is summarizedand the more recentscattered observations concerning these matters are added.The reasonsto treat the threeforms as distinct species are discussed. The identificationproblem is consideredin detail,using the San DiegoNatural History Museum (SDNHM) collection as a reference. Adult Red-breastedSapsuckers can be easilyidentified by their red hood, with or without white and black head markings. Red-naped Sapsuckersare very similarto Yellow-belliedSapsuckers but havea red patchin the middleof the nape. In addition,male nuchalis have an extensivered throat patch, overlapping the malarstripe, while female variushave a completelywhite throat. Usually,female nuchalis have a white chin and a red throat but somehave the throat entirely red, and are very similar to male varius. In juvenile plumage,varius can bestbe told from nuchalisby its spottedcrown (nuchalis has a uniform crown);ruber is characterizedby indistincthead striping and often a reddishsuffusion over the hood. At later stagesRed-naped and Red- breastedSapsuckers show very rapidly the red areasof the adult plumage;Yellow-bellied Sapsuckers, on the contrary,are very slowin acquiringthose marks;a scatteringof red featherson the crownis typical of them. Additionalcharacters are discussedin the text, both for adults and for iramatures,and this summaryshould by no means be usedas a "key". The distributionin Californiaand Baja Californiais summarized from standard sources,recent literature, and with the help of the SDNHM collection. The Red-breastedSapsucker is fairly widespread as a breeder in the mountainousand northern areas,wintering every- where,except in the desert. The Red-napedSapsucker is a very local breederin extremeeastern California, wintering in southernCalifornia and in Baja California. The Yellow-belliedSapsucker, not previously recordedfrom eitherstate, is representedby a specimenin the SDNHM collection,an immaturefemale taken in Decemberalong the lower Colorado. An individualof the northernrace of ruber, from San Diego County, is described;the racehad not beenrecorded from the two states. Severalhybrid ruber x nuchalis,nuchalis x daggettiand particularly one varius x nuchalisfound in the SDNHM collectionare mentioned. 74 SAPSUCKER IDENTIFICATION & DISTRIBUTION

Finally, extralimital recordsin the groupare discussedand it is arguedthat many result from the interbreeding between the forms.

LITERATURE CITED

American Ornithologists' Union. 1957. Check-list of North American birds. Fifth ed. Amer. Ornithol. Union, Baltimore. Austin, G. T. and W. G. Bradley. 1965. Bird records from southern Nevada. Condor 67:445-446. Bent, A.C. 1939. Life histories of North American woodpeckers. Order Piciformes. U.S. Nat. Mus. Bull. 174. Chase,T., Jr. and T. Chandik. 1966. Winter season. Middle Pacific coastregion. Audubon Field Notes 20:453-458. Cogswell, H. L. and R. H. Pray. 1955. Winter season. Middle Pacific coast region. Audubon Field Notes 9:280-284. Coppa, J. B. 1960. Sapsuckersbreeding in the HualapalMountains, Arizona. Condor 62:294. Cowan, I. McT. 1939. The vertebrate fauna of the Peace River district of British Columbia. Occ. Papers Brit. Columbia Prov. Mus. 1:1-102. Davis, J. and T. R. Howell. 1951. A record of $phyrapieusvarius variusfor California. Condor 53:102. Dickinson, J. C., Jr. 1953. Report on the McCabe collectionof British Col- umbianbirds. Bull. Mus. of Comp. Zool. 109:123-209. Forbush, E. H. and J. B. May. 1953. A natural history of American birds of eastern and central North America. Btamhall House, New York. Gammell,A.M. 1956. Nestingseason. Northern Great Plains region. Audubon Field Notes 10:390-392. Gammell, A.M. and H. S. Huenecke. 1954. Nestingseason. Northern Great Plainsregion. Audubon Field Notes 8: 350-352. Godfrey, W. E. 1966. The birds of Canada. Nat. Mus. of Canada Bull. 203. Biol. Series 73. Grinnell, J. 1901. Two races of the Red-breastedSapsucker. Condor 3:12. Grinnell, J. 1928. A distributionalsummation of the ornithology of Lower California. Univ. of Calif. Publ. in Zool. 32:1-300. Grinnell, J. and A. H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna no. 27. Griscom, L. 1932. The distribution of bird life in Guatemala. Bull. Amer. Mus. Nat. Hist. 64:1-439. Howell, T. R. 1952. Natural history and differentiation in the Yellow-bellied Sapsucker{$phyrapicus varius}. Condor 54:237-282. Howell, T. R. 1953. Racial and sexualdifferences in migration in $phyrapieus varius. Auk 70:118-126. Hubbard, J. B. 1965. The summer birds of the forests of the Mogollon Mountains, New Mexico. Condor 67:404-415. Johnson,N. K. 1965. The breedingavifaunas of the Sheepand SpringRanges in southern Nevada. Condor 67:93-123. McCaskie,G. 1964. Breedingseason. Southern Pacific coast region. Audubon Field Notes 18:534-5 36. McCaskie,G., P. Devillets,A.M. Craig, C. R. Lyons,V. P. Coughtanand J. T. Craig. 1970. A checklistof the birds of California. Calif. Birds 1:4-28. Millet, A. H., H. Friedmann, L. Griscom and R. T. Moore. 1957. Distributional check-listof the birds of Mexico, part 2. Univ. of Calif. Press,Berkeley. 75 SAPSUCKER IDENTIFICATION & DISTRIBUTION

Miller, A. H. and W. C. Russel. 1956. Distributionaldata on the bffdsof the WhiteMountains of Californiaand Nevada. Condor58:75-77. Monson, G. 1953. Winter season. Southwestregion. Audubon Field Notes 7:228-230. Niles, D. M. 1966. Additional distributional records from New Mexico. Condor 68:213-214. Peterson,R.T. 1961. A field guide to westernbffds. Houghton Mifflin Co., Boston. Phillips, A., J. Marshall and G. Monson. 1964. The bffds of Arizona. Univ. of Arizona Press,Tucson. Pough, R.H. 1957. Audubon western bffd guide. Doubleday & Co., Garden City, New York. Ridgway, R. 1914. The bffds of North and Middle America. U.S. Nat. Mus. Bull. 50, pt. 6. Robbins, C. S., B. Brnun and H. S. Zim. 1966. Bffds of North America. Golden Press,New York. Rogers,T.H. 1967, 1968 and 1969. Nestingseason. Northern Rocky Mountain- inter-mountainregion. Audubon Field Notes 21:587-590; 22:628-632; 23:675-679. Short, L. L., Jr. 1969. Taxonomicaspects of avian hybridization. Auk 86: 84-105. Shelforal,V. E. 1963. The ecologyof North America. 2nd ed. Univ. of Illinois Press,Urbana. Sutton, G. M. 1967. Oklahoma birds. Univ. of Oklahoma Press, Norman. Swarth,tt. S. 1922. Birdsand mammalsof the StikineRiver region of northern British Columbia and southeastern Alaska. Univ. Calif. Publ. ZooL 24:126-314.

APPENDIX

Date and locality of collectionof the specimensillustrated: Fig. 1, left, male varius,21 February 1930, Texas; fight, male nuchalis, 19 February 1938, Nevada. Fig. 2, left, male varius, 5 March 1933, Georgia; fight, male nuchalis, 19 February 1938, Nevada. Fig. 3, left, female varius, 28 March 1930, Georgia;fight, femalenuchalis, 27 April 1878, Colorado. Fig. 4, left, female varius, 20 April 1916, Wisconsin;right, female nuchalis, 27 April 1878, Colorado. Fig. 5, below, female nuchalis,25 July 1903, Colorado; above, male varius, I October 1891, New York. Fig. 6, immature varius;above, female,26 October 1928, Georgia;center, female, 18 December1938, California; below, male, 5 October 1927, Georgia. Fig. 7, and 8, above, juvenile male nuchalis, I August 1917, Modoc County, California; center, immature female vagus, 18 December 1938, California; below immature female varius, 18 December 1924, Georgia. Fig. 9 and 10, left, juvenile female nuchalis, 19 August 1917, Modoc County, California; fight, juvenile daggetti, 14 August 1885, San BernardinoMountains, California. Fig. 11, above,ruber, 2 November 1913, Oregon;center, ruber, 9 November1957, San Diego County, California; below, daggetti, 5 December 1926, Baja California. Fig. 12, above,ruber, 2 November 1913, Oregon;center, female nuchalisx ruber, 31 December 1916, California;below, malenuchalis, 19 February 1938, Nevada.

11 av. de l'Oiseaubleu, 1150 Bruxelles,Belgium; presently, AMES Dept., Univ. of Californiaat San Diego, La Jolla, California92037. 76