EVOLUTIONARY IN TRENDS THE NEOTROPICAL AND OVENBIRDS WOODHEWERS BY ALAN ORNITHOLOGICAL FEDUCCIA MONOGRAPHS PUBLISHED THE AMERICAN BY ORNITHOLOGISTS' 1973 NO UNION 13 EVOLUTIONARY IN TRENDS THE NEOTROPICAL AND OVENBIRDS WOODHEWERS BY ALAN ORNITHOLOGICAL FEDUCCIA MONOGRAPHS PUBLISHED THE AMERICAN BY ORNITHOLOGISTS' 1973 NO UNION 13 ORNITHOLOGICAL MONOGRAPHS This series,publishedby the American Ornithologists'Union, has been established for major paperstoo long for inclusionin the Union'sjournal, The Auk Publicationhasbeenmadepossiblethroughthe generosityof Mrs Carll Tucker and the Marcia Brady Tucker Foundation,Inc Correspondence concerningmanuscriptsfor publication in the series shouldbe addressed to the Editor, Dr JohnWilliam Hardy, FloridaState Museum,Universityof Florida, Gainesville,Florida 32601 Copiesof Ornithological Monographsmay be orderedfrom the Treasurer of the AOU, Burt L Monroe,Jr., Box 23477, Anchorage,Kentucky40223 (See price list on insideback cover.) Ornithological Monographs, No 13, iv q- 69 pp Editor-in-chief,John William Hardy SpecialAssociateEditors for this Issue, Stuart L Warter and Peter L Ames Issued July 10, 1973 Price $2.00 prepaid($1.60 to AOU Members) Library of Congress CatalogueCard Number73-81856 Printed by the Allen PressInc., Lawrence,Kansas66044 TABLE INTRODUCTION Woodhewer Ovenbird CONTENTS COMPARATIVE ANATOMY Anatomical OF material OF THE SKULL 11 skulls skulls 12 14 Philydorine skulls 17 Skulls of the "intermediates" _ 22 Jaw muscles 24 Functionalaspectsof the skulltypes 25 STERNUM EVOLUTION OF THE SCANSORIAL FOOT Limb proportions Distal end of the tarsometatarsus Femur and tibiotarsus 34 36 ß 36 41 42 The digits 43 TAIL 45 SYRINGEAL ANATOMY 45 ELECTROPHORESISOF HEMOGLOBIN Methods and materials Results and discussion 48 48 49 CLUSTER ANALYSIS 51 A PHYLOGENY 59 A BEHAVXORIAL MODEL 61 CLASSIFICATION 64 SUMMARY 65 LITERATURE CITED 68 INTRODUCTION The Neotropical ovenbirds (Furnariidae) and woodhewers (Dendrocolaptidae)have long been consideredto be closelyrelated on the basisof derivedcharacters whichare sharedby the two groupsbut not foundin other suboscine birds Generalplumagepatternsin the two groupsare amongthe significantly strikingsimilarities,as almostall species havelight brownto reddish-brownbodyplumagewith variousdegreesof spottingon the breastand back,oftenwithlightthroatpatches.A spinytail,usuallyof chestnut or ferruginouscolor,whichis usedin the woodhewersas a bracein climbing,is found in variousdegreesof development in many membersof the Furnariidaeand is well developedin certainovenbirdswhich foragelike the woodhewers,by climbingup tree trunks These scansoffalfurnariids,includingPseudocolaptes,Xenops,Pygarrhichas, the Margarorniscomplex,and somespecies of Cranioleuca, are of interestin that, althoughthey are behaviorallysimilar to the woodhewers, beingtree-trunkforagersand possessing stiff, spinytails, they are clearlymembersof the Furnariidaeon the basisof suchcharacters asthe syrinx,cranialmorphology, andfeet Commonwingpatternsare found in the Furnariidaeand Dendrocolaptidae In addition,syringealand osteologicalcharacters ally thetwo groups.It is onlywithinthe Dendrocolaptidae and Furnariidaethat two pairs of intrinsicsyringeal(tracheo-bronchial) musclesare found (Ames, 1971) This sharingof characters hasled manyornithologists to question the distinctness of the two families Thus the familial classification of the furnariids and dendrocolaptids haslong beenin a stateof uncertainty,and at present thereis little agreement amongornithologists concerning the recognition of familiesin the group Recentclassifiers havegenerallyfollowedeithervon Ihering(1915), who presented evidencewhichhe considered favoredmergingthetwofamilies,or Ridgway(1911), whorecognized twofamilies.Stresemann (1934) unitedthe ovenbirdsandwoodhewers into onefamily In 1951 threeclassifications wereproposed.Wetmore(1951) retainedtwo families becausehe consideredvon Ihering'sevidenceinconclusive; Peters (1951) alsorecognizedtwo families However,Mayr and Amadon (1951) treated the entiregroupas a singlefamily, as did Storer (1960) Early classifiers(see Garrod, 1873; and Beddard, 1898) placedconsiderable importanceon the conditionof the nasal bones in the classificationof the higher categoriesof birds Two basic arrangementsof the nasal openingswere distinguished, schizorhinaland holorhinal In the former, the nasal openingextendsposteriorto the nasal-frontalhinge; in the latter, the posterior extentof the openingis anteriorto the hinge The conditionin Furnarius and other ovenbirds,which was originallytermed schizorhinal(see Garrod, 1877), was later recognizedas not homologousto the conditionin other ORNITHOLOGICAL MONOGRAPHS NO 13 schizorhinalbirds (charadriiform birds, etc.), and F'tirbringer(1888) proposedthat the term pseudo-schizorhinal be appliedto the conditionin those ovenbirdsin which the posteriorextent of the nasalopeningis rounded,insteadof endingin a slit asin "true"schizorhiny Garrod (1877) emphasizedthat the conditionof schizorhiny(= pseudoschizorhiny)in the ovenbirdswasof sufficienttaxonomicimportanceto separatethe groupfrom the holorhinalwoodhewers.However,Garrod had examinedonly a small numberof species.Von Ihering (1.915) examineda muchlargerseriesof speciesand concludedthat therewas actuallyno clearcut divisionbetweenthe pseudo-schizorhinal ovenbirdsand the woodhewers, and that the differencesbetweenpseudo-schizorhiny and holorhiny representedslightmodifications from a basicpatternand were thereforeof little taxonomicimportance,exceptperhapsin characterizinggenera Ridgway (1911), however,had maintainedthat the differencein the arrangementof the nasal openingplus the differencesin the feet were of sufficientimportanceto separatethe Dendrocolaptidae from the Furnariidae In the Furnariidae(sensuRidgway)the outertoe is shorterthan the middletoe and the hallux without the claw is not shorterthan the inner toe (no II) without the claw The middletoe is unitedto the outertoe by lessthanthe wholeof the secondphalanx In the Dendrocolaptidae (sensuRidgway) the outer toe is aboutas long as the middletoe and muchlongerthan the inner toe, and the hallux without the claw is shorter than the inner toe The three anterior toesareunitedfor the entirelengthof the basalphalanx,andthe middletoe is fusedto the outerby almostthe full extentof the secondphalanx Ames(1971) in hissystematic conclusions of the Furnariiemphasized that the syringealmusculatureof the ovenbirdsand woodhewers was an indication of closeaffinityof the two groups.Bothgroupspossess two pairsof intrinsic syringealmuscles,a characterwhich separatesthe two families from the antbirds (Formicariidae) and tapaculos(Rhinocryptidae) However, the ovenbirds are apparently separable from thewoodhewers on the basisof the absencein the ovenbirdsof horns on the Processivocales (except in the genusGeositta) It is alsoof interestto note that thereis far more syringeal variation within the Formicariidae than within the woodhewer-ovenbird as- semblage Attemptsby many classifiers to place animalsinto distinguishable groups without examiningin detail the charactersinvolvedhas led in many cases to classifications basedon the most adaptivefeaturesof the birds, namely the bill and feet (the classicalexamplebeinghawks and owls which were at one time classified togetheron the basisof havingsimilarfeet and bills) with little emphasison decipheringthe evolutionarypathwaysinvolved The problem in the woodhewer-ovenbird groupshas been the same as that for other 1973 EVOLUTION IN OVENBIRDS AND WOODHEWERS Figure Two "strong-billed" woodhewers, an "intermediate," and two philydorine furnariids.From top to bottom: Xiphorhynchu.• lachrymos'us' (actuallength,229 ram), Xiphorhynchusguttatus',Dendrocinclaanabatina,Syndactylasubalaris,Automolus ochrolaemus ORNITHOLOGICAL MONOGRAPHS NO 13 groupsof passerine birdswherethereis a largeamountof adaptiveradiation for particularmodesof life The woodhewer-ovenbird problemis of interestfor severalreasons.First, the two groupsare very closelyallied,yet exhibitperhapsthe greatestadaptire radiationin any group of New World passefinebirds, with climbing formsapparently havingevolvedindependently in manysituations.Second, cranialmorphology in the two groupsdiffers;therefore,the possibility of resolvingthe polarityof this evolutionexists Most important,however,are four genera,Dendrocincla,Sittasomus, Deconychura,and Glyphorhynchus, whichare normallyplacedin the Dendrocolaptidae becausetheypossess most of the characters of that family, but whichshowother characters that ally them with the Furnariidae These forms, which I shall term the "intermediates,"form the startingpoint of this study (see Fig 1) Initially, my main interestwas in the evolutionof the differenttypesof cranialmorphology in the ovenbirdsand woodhewers.An examination of the skulls of woodhewersshowedthat most forms of the Dendrocolaptidae conformed to a basicpattern.Thesegenera,whichincludeall of the woodhewersexceptthe four intermediates, are the formsthat I shall term the "strong-billed"dendrocolaptids; they appear to representa monophyletic groupon the basisof the skull and other characters.The "intermediates," Dendrocincla,Sittasomus,Deconychura,and Glyphorhynchus, are of particularinterest.Exceptfor Dendrocincla(whichforagesin a varietyof postures) the "intermediates" are behaviorallylike the woodhewers in that they forageby hitchingup treetrunks.They alsopossess the woodhewer type of syrinxand foot arrangement.However,they are clearlyintermediate betweenthe holorhinaland pseudo-schizorhinal types of nasal bone arrangements Further, it was of interestto find that, of the four subfamiliesof the Furnariidae(whichappearto be fairly well defined),the membersof the subfamilyPhilydorinae, the forest-dwelling furnariids,are the formsthat possessan intermediate arrangement in the conditionof the nasalbones,and some,suchas Hyloctistesand Automolus,are similar to the "intermediate" woodhewersmentioned above The other subfamiliesof the Furnariidae, the Synallaxinae, Furnariinae,and Sclerurinae, are composed almostentirelyof memberswhichare pseudo-schizorhinal, althoughin somespeciesthe nasal foramen is somewhat shortened This interesting situationled me to a literaturesurveyin whichI foundthe oneimportantpaperon the relationships of the woodhewers and ovenbirds, that of yon Ihering (1915) In it he discusses the findingsof his investigations of the cranial morphologyof the two groupsand recordsmuch the same observationsthat I have discussedabove He stated (1915: 147) that, "Pronounced holorhinyis foundonly amongthe Dendrocolaptinae of which, 1973 EVOLUTION IN OVENBIRDS AND WOODHEWERS ORNITHOLOGICAL MONOGRAPHS NO 13 however,somegenera Sittasomus, Dendrocinclaand probablyothers are typically schizorhinal."At that time he had not examinedthe genera Glyphorhynchus andDeconychura.He furtherstatedthat, "The Philydorinae (Philydor,Xenicopsis,Xenops,etc.) form a transitiongroupleadingup to the Dendrocolaptinae and the speciesare schizorhinal with the exceptionof Automolus and Anabazenopswhich have the nasal foramen shortened." Althoughyon Ihering'sdivisionsare not easy to discernit is clear that an intermediate conditionof the nasalopenings existsin membersof the Dendrocolaptidaeand the subfamilyPhilydorinaeof the Furnariidae An examination of the skinsof theseintermediate species of dendrocolaptids provedeven moreinteresting, for in theseformsthe plumagepatternsare in someaspects alsointermediate.One strikingplumagecharacterthat seemedparticularly significant wasa rufouswingstripe(seeFigs.2 and 3) whichoccursin various membersof the Furnariidae,but within the Dendrocolaptidae is found only in Glyphorhynchusand Sittasomus In Dendrocincla anabatina there is a similarbut more diffusewing stripe However,Dendrocinclais intermediatein othercharacters.The tail doesnot possess the striking,stiff,spinelike rectricescharacteristic of all othermembersof the Dendrocolaptidae and is, in fact, morelike the typepossessed by membersof the Philydorinae.Also the bill and generalbody shapeof Dendrocinclaappearto be more philydorine-likethan dendrocolaptine My ownfield observations, aswell asthose of other authors, show Dendrocincla to be intermediatein behavior (see Feduccia,1970) The speciesof Dendrocincla hitchup tree trunkslike the otherwoodhewers, but alsoforagein a varietyof otherways Thus,the four genera, Dendrocincla, Sittasomus,Deconychura, and Glyphorhynchus,although not sharingidentical characters,all possesssome features that are intermediatebetweenthe Dendrocolaptidaeand Philydorinae These"intermediates" may representsimply"old" formsthat have retained many primitivecharacters.However, becausethe advanced(derived) character stateswithin the "strong-billed"dendrocolaptidsare indeed those that are concernedwith tree-trunk foraging, and the "intermediates"(with the exceptionof Dendrocincla) are virtually identical to the "strong-billed" woo.dhewers in their climbingbehavior,the situationis indeed curious It would seemreasonableto expectthe evolutiono.f thosecharactersthat increaseefficiencyin climbing and tree-trunk foraging to occur, as has occurred in other unrelatedtree-trunkforaginggroups One can test whether or not a given characterstate representsan actual climbing adaptationby lookingat the samecharacterstatein unrelatedgroupsof birds (see Richardson, 1942) The possession by the "intermediates"of charactersintermediatebetween perchingand scansorialadaptations,plus the possession of plumageand 56 ORNITHOLOGICAL MONOGRAPHS NO 13 of the extensormuscleof the toes (2) is found in most woodhewers A number of intermediates( 1) are present Distal end of tarsometatarsus (Fig 13) The typical passerinecondition (0) with a large metatarsalI, only slightexcavationof the trochleafor digit III, and a not greatlyexpandedbaseof the distalendis foundin mostof the ovenbirds The woodhewertarsometatarsus(2) exhibits a small metatarsal I (an indicationof a smallhallux), great excavationof the trochleafor digit III, and expansionof the baseof the distal end A numberof intermediate characterstatesare known (1) General foot structure (Fig 16) The typical anisodactylfoot (0) is found in most ovenbirds There are intermediates (1) which lead to the woodhewercondition(2) in which the third and fourth toes are of equal length,a reducedhallux is present,and there is externalfusionof the basal phalanges, andstronglycurvedanteriorclaws Syrinx There are two characterstatesof the syringesof ovenbirdsand woodhewers.The woodhewercondition(1) with elaborateProcessihaving projectinghornsfor the attachmentof musclesis derivedfrom the ovenbird condition (0) in which horns are lacking on the Processi Although Ames (1971) did not examinecertaingeneraincludedhere, I am assuming tentatively that Coryphistera,Cranioleuca,Margarornis, Hyloctistes,Syndactyla, Anabacerthia,and Thripadectesamong the furnariids possessthe syrinx without horns on the Processi,and that Deconychuraand Dendrexetastesamongthe unexamined dendrocolaptids possess the syrinxwith horns on the Processi 10-15 Hemoglobinelectrophoretic pattern (Fig 18) Each OTU is coded for the absence(0) or presence(1) of each of the six differenthemoglobin bands that occur in the ovenbirds and woodhewers Those ovenbirds and woodhewers for whichno hemoglobindata are availableare assumedto possessthat of their respectivegroup 16 Wing stripe(Fig 3) A rufouswing stripe (1) is presentin many furnariids and in the "intermediates," but absent (0) in the "strong-billed" dendrocolaptids The diffusewing stripein Dendrocinclaanabatinais coded as 17 Solidreddishwing (Fig 2) The "strong-billed" woodhewers possess a solidreddishwing (1) All otherformsare coded0 18 Tail (see skin photographs, Fig 1) The degreeof stiffeningof the tail is coded from the lack of stiffness (0) to the most advancedcondition of stiffening foundin thewoodhewers (3) 19 Sternalnotches(seeFeduccia,1972) The posteriorborderof the sternum EVOLUTION 1973 IN OVENBIRDS TABLE AND WOODHEWERS 57 COMPARISONOF THE CLASSIFICATIONS OF SCLATER(1890), AND HELLMAYR (1925) SCLATER HELLMAYR Family Dendrocolaptidae SubfamilyFurnariinae SubfamilySynallaxinae SubfamilyPhilydorinae SubfamilySclerurinae SubfamilyDendrocolaptinae x Family Furnariidae SubfamilyFurnariinae SubfamilySynallaxinae SubfamilyMargarornithinae SubfamilyPhilydorinae Subfamily Sclerurinae Family Dendrocolaptidae Sclater includedMargarornis, Premnornis,Premnoplex,and Pygarrhichaswithin the Dendrocolaptinae Excluding those genera, Sclater's order for the subfamily was: Sittasomus,Glyphorhynchus,"strong-billed"woodhewers,Dendrocincla (which included Deconychura), and the "strong-billed"dendrocolaptids The order in Hellmayr's Dendrocolaptidaeis: "strong-billed"woodhewers,Glyphorhynchus,$ittasomus,Deconychura, and Dendrocincla of mostovenbirdsis generallytype Many species possess type sternabut showa tendencyto openfurther (0), somepossess onlytype sterna(1), and somepossess type3 sternabut with sometendencyto closefurther (2) 20 Nasalcondition(Figs 4-8) The pseudo-schizorhinal conditionis found in a largenumberof ovenbirds(0) An intermediatecondition(1) leadsto the solidholorhinalskull (2) found in mostof the woodhewers 21 Orbital processof the quadrate(Figs 4-8) The tip of the orbitalprocess of the quadrategoesfrom the conditionin the ovenbirdswith no expansion (0) through intermediatestagesof expansion(1) to the great expansion foundin the "strong-billed" woodhewers (2) 22 Ectethmoidcomplex(Figs 4-8) The ovenbirdcondition(0) of having a broadplatetilted anteriorly,with a slightwingthat doesnot meetthe jugal bar, goesthroughintermediatestages(1) to the woodhewercondition (2) of havinga relativelysmallerbut strongerplate which is not tilted anteriorly, but which is constrictedmesiallyand sendsout a large wing that meets and abutsagainstthe jugalbar 23 Supraorbitalarea of frontal bones(Figs 4-8) The narrow conditionof the supraorbitalarea of the frontalbones(0) in the ovenbirdsgoesthrough intermediate stages(1) to the broadcondition(2) foundin the woodhewers 24 Interorbitalseptum(Figs 4-8) An unossifiedinterorbitalseptum(0) in the ovenbirdsgoes through intermediatestagesof ossificationin the 58 ORNITHOLOGICAL MONOGRAPHS NO 13 philydorines(1) to the extremelyossifiedcondition(2) found in the woodhewers 25 Zygomatic and postorbitalprocessesand temporal fossa (Figs 4-8) Small processesand a small fossa (0) are presentin most of the ovenbirds Intermediatesin the philydorines(1) lead to the strongprocessesand deep fossa(2) that characterizethe "strong-billed"woodhewers 26 Nest Most of the ovenbirdsbuild large stick structures(0) The mud structureof Furnarius is arbitrarily coded (0) Some ovenbirdsexcavate tunnels(1) or nestin holesor cavitiesin treesor stumps(2) as the woodhewers 27 Habitat The habitat is codedas non-forest(0), or forest (1) RESULTS AND CONCLUSIONS The resultsof the Prim Network are shownin Figure 19 The Prim Network supportsthe following The "strong-billed"woodhewersrepresenta cohesivetaxonomicunit, fairly well separatedfrom the furnariids,but bridgedby four intermediategenera There is no attempthere to decipherany cladisticinformationfrom the Prim Network However, I should point out that the Network in no way contradictseither a monophyleticor multiple origin hypothesisfor the Dendrocolaptidae(sensuRidgway), but in fact, the Prim Network doesshowDendrocinclacloser to the philydorinefurnariids than to the "strong-billed" dendrocolaptids.Additionally,it showsSittasomusand Deconychuraas being very closelyallied, and Glyphorhynchus approximatelyhalfway between the philydorinesand the "strong-billed"dendrocolaptids As suspected the philydorinesas a group are closerto the woodhewersthan are any of the other ovenbirds.Also, the philydorinesseemto form a cohesivetaxonomic unit, thus lending support to their subfamilial status The placement of Xenopsclosestto the "intermediates"and other woodhewersis not surprising, and has beensuggested at differentplacesthroughoutthis paper on the basis of singlecharacters.The areaof the synallaxines andfurnariineson the Prim Network is more confused,for thesetwo groupsare probablymore closely allied to each other than is either to any other group within the ovenbirdwoodhewerassemblage The lack of a largenumberof derivedspecificcharactersin this analysisprohibitsdrawingany major conclusions from the far left-hand side of the Prim Network, except that the synallaxinesand furnariinesare very closelyrelated The only point of interestis that mostof the presentlyclassifiedsynallaxines clusterwith eachother, as the furnariines Again, one might questionthe use of hemoglobinas six separatecharacters insteadof one I must emphasizethat it has little effect on the major con- 1973 EVOLUTION IN OVENBIRDS AND WOODHEWERS 59 clusionsof the Prim Network, for when the samecomputerprogramis run withoutusingany hemoglobincharactersthe only effectsare as follows: 1) the pheneticdifferencesbetweenDendrocinclaand Sittasomus,and between Dendrocinclaand Glyphorhynchusare reducedby a linear distanceof approximatelyone-halfthe lengthshownin Figure 19; and 2) Xiphorhynchus triangulariscomes off from Deconychurarather than from Glyphorhynchus In other words, Glyphorhynchusis lesswoodhewer-likeif hemoglobinis excluded from consideration A PHYLOGENY A hypotheticalphylogenyof the furnariidsand dendrocolaptids is shown in Figure20 The evolutionof trunk-foragingtypes in the groupsunder consideration has involvedtwo major ancestraltypes On the one hand the philydorines haveapparentlygivenriseto the woodhewergroupsfrom possiblyone or several differentlines, and on the other hand the synallaxineshave probably given rise to a number of creepingtypes, includingthe Margarornis-Premnornis-Premnoplexcomplex,and Cranioleuca,somespeciesof which hitch up tree trunksin their foragingbehavior There is alsoPygarrhichas,which, although closestto the membersof the Furnariinae and Sclerurinaein cranial morphology, mustremainin the category"incertaesedis."The zoogeographic data are perfectlycompatiblewith the abovestatements.The Philydorinae and the woodhewersare both primarily Amazon Basin forest groupsand occur in almostequal numbersin every countryin which they are found, whereasthe synallaxinesoccur primarily outsideof the Amazon Basin forestedregions,as alsothe trunk-foragingforms, Margarornis,Premnornis, Premnoplex,and Cranioleuca Most of theseforms occur in highlandsituations where the numbersof woodhewerspeciesare greatlyreduced Pygarrhichasoccursin a regionwhich has no woodhewers The anatomical evidence advocates a derivation of the woodhewers from philydorine-likeancestors.There appearsto have been one great radiation of woodhewersthat resultedin what I term the "strong-billed"woodhewers, which includesthe generaDrymornis,Nasica, Dendrexetastes, Hylexetastes, Xiphocolaptes, Dendrocolaptes,Xiphorhynchus, Lepidocolaptes,and Campylorhamphus.Other generamay be later derivativesfrom philydorine-like ancestors.Somepossess a furnariidwing patternand many anatomicalfeaturesthat ally themwith the ovenbirds,althoughin creepingbehaviorthey are identicalto other woodhewers.These generaincludeGlyphorhynchus,which possesses somecranialcharactersand other anatomicalfeatureswhich ally it with the philydorines,and the wing stripe commonlyfound in ovenbirds, but has the electrophoretichemoglobinpattern of the woodhewergroup 60 ORNITHOLOGICAL MONOGRAPHS NO 13 DECONYCHURA SITTASOMUS Figure 19 The Prim Network The length of the lines between the various OTUs is a direct indication of the pheneticdistanceas decipheredby the computer The actual names of the OTUs are as follows: Furnarius ru/us, Certhiaxis cinnamomea, Synallaxis brachyura, Margarornis rubiginosus,Anumbius annumbi, Coryphistera alaudina, Upucerthia dumetaria, Cinclodes ]uscus, Geositta cunicularia, Phacellodomus striaticollis, Cranioleuca erythrops, Phleocryptes melanops, Syndactyla ru]osuperciliata, Pseudo- colapreslawrencii, Thripadectesrufobrunneus,Hyloctistes subulatus,Automolus ochrolaemus, Philydor lichtensteini,Anabacerthia striaticollis, Xenops minutus, Dendrocincla anabatina, Sittasomusgriseicapillus,Deconychura longicauda, Glyphorhynchus spirurus, Xiphorhynchus triangularis, Xiphorhynchus guttatus, Lepidocolaptes souleyetii, Dendrocolaptescerthia, Dendrexetastesru]igula, and Campylorhamphus pusillus Deconychuraand Sittasomusalso appear to be closer to philydorine-like ovenbirds.Theseformspossess somecranialand other anatomicalcharacters that ally them with the philydorines,but in skull structureare very similarto each other Although Deconychurapossesses the dendrocolaptidwing pattern, Sittasomushas the samewing stripe that is found in Glyphorhynchus and commonlyin ovenbirds The hemoglobinpatterns in both Sittasomus and Deconychura are different from either the woodhewer or the furnariidpatterns,but are like eachother The last "intermediate,"Dendrocincla,alsoappearsvery philydorine-like in its characters.Of the "intermediates" Dendrocinclais closestto the philydorinesin skull structureand in other anatomicalcharacters,and in behavioris a perfectintermediatebetween thephilydorines andthe woodhewers.The wingpatternof mostof the species of Dendrocinclais like that of the woodhewers; D anabatinapossesses a wing stripe similar to that of many furnariids,but somewhatmore diffuse The hemoglobinof Dendrocinclais identical to that of ovenbirdsin its electrophoreticpattern Of all the charactersanalyzedin this paper, the "intermediates"appear 1973 EVOLUTION IN OVENBIRDS AND WOODHEWERS 61 furnariid-likein someand dendrocolaptid-like in others One seeminglyimportantwoodhewercharacterwhich all of the "intermediates" possess is the woodhewertype of syrinx;Geositta,however,a typical furnariid in most othercharacters, alsohas a dendrocolaptid-like syrinx Heimerdinger(pers.comm.) hasfound that Dendrocincla,Sittasomus,and Glyphorhynchus conformto the woodhewerpterylographic pattern The total analysis seemsto indicatethat therewasonelargeradiationof woodhewers from philydorine-likeancestors that resultedin the evolutionof the "strong-billed" woodhewers Whetheror not subsequent offshoots from the philydorine-like ancestors resultedin the "intermediate" genera(seeFig 20) is difficultto determine.The alternativeto a morerecentoriginof the "intermediates" from philydorinestockis that they simplyrepresentwoodhewersof an initialmonophyletic radiationthat haveretainedmanyprimitive characters, but aswe are dealingwith tree-trunkforagersonewonders why a woodhewerwould retain primitive (=less efficient) tree-trunkforaging adaptations throughtime The total pheneticdistancewithin the ovenbirds andwoodhewers is expressed by a computerclustering program(Fig 19) Thesedataare compatible with eithera mono-or polyphyletic originof the woodhewers The relationships withinthe ovenbirds are evenlessclear The exactposition of the synallaxines, furnariines,and sclerurines wouldbe very difficult to ascertain.It seemsreasonable,however,that some "holorhinal"prepasserine or passefine probablygaveriseto a "schizorhinal" groupwhichresultedon the onehandin the evolutionof the philydorines, the forestovenbirds, and on the other hand, the synallaxine-furnariine groups Later, generalossification of the skullincreased in the philydorines due to selection forcesfor strongerskullsassociated with foraginghabits This led to a seriesof holorhinalphilydorines,which, concomitantwith scansorialtendencies, gaveriseto woodhewer-like forms,andeventually to a radiationof woodhewers intotheirnewadaptivezone A BEHAVIORAL MODEL If we assumethat the woodhewers are derivedfrom ancestors resembling the livingphilydorine ovenbirds, andthis seemsto be a safeassumption on thebasisof anatomy,behavior,andzoogeography, thenwe shouldbe ableto summarizemore properlythe types of evolutionarytrends involvedin a transitionto the woodhewergradeby lookingat anatomicaland behavioral seriesin the Recentforms One thingthat seemsto be fairly well established is that all that is reallyneededto producea climbingbird from any group of the Passeriformes is the necessary behavioraladaptations.The passerine bodyform,although typicallyfor a perching bird,is suitedfor trunkclimbing 62 ORNITHOLOGICAL MONOGRAPHS NO 13 DENDROCOLAPTIDAE Z Z m •':> , I ,, i •"O O"" ., "•Z HOLORHINY % '•HEMOGLOBIN CHANGE _OTHER SCHIZORHINY •' SUBOSC INES HOLORHINY *HORNS IN SYRINX Figure20 Hypotheticalphylogenyof furnariidsand dendrocolaptids Bracketed groupsshownto therightabovewereincluded in the Dendrocolaptidae sensuRidgway also,andthereare climbingformsin manyof the passerine families.In the furnariids, the preadaptations for trunkclimbingseemvery apparent.One ofthemoreobvious of these isthestiff,spinytailfoundin manynon-climbing forms.Also,manyof thephilydorines thatclingandforagein a varietyof wayspossess variousdegreesof development of curvedclaws,and otherfoot characters associated withclimbing 1973 EVOLUTION IN OVENBIRDS AND WOODHEWERS 63 Of greatinterestis the genusDendrocincla,membersof whichforagewith diversity,bothfrom a typicalperchingbird stance,andfrom the trunk climbing stance As Willis (1966: 667) has summarized,"This woodcreeper ordinarilyclingsto the trunksof treesand saplingsin or near tropicallowland forestsand salliesout like a flycatcherto snapprey off the groundor vegetation.It occasionally pecksprey off the surfacevegetation,but it rarely movesabout peeringand probinginto the bark or tangledvegetationin the fashionof many speciesin the family Dendrocolaptidae."Willis (op cit.) studiedthesebirdsin tropicalforestsituationswhereDendrocinclais a normal constituentof mixed flocksthat follow army ant swarms,where the arthropodsand small vertebratesthat flee the advanceof the ant swarm are easy prey for the ant-followingbirds In these situationsWillis recorded the changesin the foragingbehaviorof Dendrocincla[uliginosaby recording " changesof heightof waitingbirds or changesin heightsat which prey items are taken." He (1oc cit.) found that, "When Plain-brown Woodcreepers(Dendrocinclafuliginosa) follow swarmsof army ants on Barro ColoradoIsland,PanamaCanalZone,theyforagein the zonenearthe ground more frequentlywhen OcellatedAntthrushes(Phaenosticus mcleannani)are absent.The ground-foraging antthrushes regularlysupplantthe smallerwoodcreepers,whichthen moveto higheror to peripheraland lessproductivezones This seemsa clearexampleof competitiveexclusionby dominance.On Trinidad, wherecompetinglow-foragingantbirdsare nearlyalwaysabsent,fuliginosa foragesnear the ground at swarms In British Guiana, where several smallantbirdssaturatethe lowerlevelsoverthe ants,[uliginosaagainforages high in the undergrowth."Thus, Dendrocincla[uliginosaappearsto forage morediverselywhencompetitors are present,and asWillis (op cit., p 670) says,"By wideningits foragingzonein the presenceof competitors,[uliginosa probablyobtainsmore food than it would if it continuedto forage in the narrow zone near the ground." In other words, in this case it may be that competitionin thesemixed speciesforagingflockscausessomespecies,like Dendrocincla[uliginosa,which are capableof diverseforagingbehavior,to includenew strategiesin foragingbehaviorand therebyincreasetheir food intakewith a minimumof aggressive distractions Let us now examinewhat might be involved in the evolutionof a woodhewertype from a philydorinefurnariid Both woodhewers and philydorines are frequent army ant followers, althoughforms of Dendrocinclaare more nearly obligatefollowersthan other woodhewers.In these situationswhere frequentaggressive encounters occur,it may be of greatselectiveadvantage to be very flexible in foragingbehavior,and one can imaginehow a scansorial foragingstrategymightbe advantageous The majorityof philydorines forage in a greatvarietyof waysand manyspecieshitchup tree trunksat times In 64 ORNITHOLOGICAL MONOGRAPHS NO 13 somehighlandsituationswherewoodhewers are absentexceptfor one or at mosttwo species,the margarornithine furnariids (Margarornisand related genera),andPseudocolaptes frequentlyforagelike woodhewers, hitchingup tree trunks In the high Andes,Cranioleucaantisiensis foragesby hitching up tree trunks;it existsin areaswhereno woodhewersare present,as does Pygarrhichasof southernSouthAmerica Sincethe necessary preadaptations are presentin the furnariidsfor treetrunkforaging,all that is reallynecessary is selection for behavioralflexibility that will allow tree-trunkforagingto begin,whetherbecauseof the lack of woodhewers, or becauseof advantages gainedwhere competitionis great, as in lowland rain forest situations.In thesecases,the first step may have beentaken in becominga woodhewer.Selectionforcescan then operateon perfectionof theseadaptations for tree-mink foraging,and oncethis transition zonebetweencreepingand perchingis abandoned, selectionfor adaptationsfor moreeffectivetrunk foragingmay occur Theseselectionforcesmay thenbe operatingon the perfectionof climbingadaptations, includingchanges in cranial morphology,limb proportions,and other morphologicalfeatures that leadto thewoodhewerlevelof organization CLASSIFICATION One of the practicalproblemsthat arisesfrom this studyis that of the classification of the group In traditionallinear classifications it has been customaryto place thoseforms showingthe greatestnumberof primitive characters first in the linearsequence.For mostof the ClassAvesthishas beenimpossible, owingto the fact that we simplydo not know whichforms are the more primitive For example,lookingat the classas a whole,there is no compellingreasonwhy suchbirds as the ratites,or loons and grebes shouldbe placednearthebeginning of the linearsequence, thusimplyingthat they are amongthe mostprimitiveof birds Both loons and grebesare very specialized.So, in most avian classifications the linear sequencerepresents a convenientclassification that has no basisin termsof placementof primitive and advancedforms, but which is, in itself, useful In the case of the furnariidsand dendrocolaptids I would proposethat we now have sufficient informationat least to place thoseforms with the greatestnumber of advancedcharacterslast and the less specializedforms first in the sequence The evidencenow seemscompellingthat the furnariidsand dendrocolaptids are a monophyleticgroup within themselvesand different from other suboscinebirds It also seemsreasonableto follow the evidenceindicating a closeaffinityof woodhewers to philydorine furnariids.Theselinesof evidence not seemincompatiblewith the classification usedby Sclater(see Table 4), with a few changes.I would recommendthat the more generalizedSynallaxinae precedethe more specializedFurnariinae The terrestrialor semi- 1973 EVOLUTION IN OVENBIRDS AND WOODHEWERS 65 terrestrialFurnariinaeare perhapslikely derivatives of the more "generalized" synallaxines.Sclaterhad includedMargarornis,Prernnornis,and Premnoplex(the margarornithines) within the Dendrocolaptinae probably owingto theirscansorial habits,andgeneralresemblance to the woodhewers Theseforms,however, areclearly"ovenbirds" andareprobably closelyallied to the synallaxines, at leastin cranialosteology.I wouldrecommend their placementat the end of the Synallaxinae Sclaterhad alsoincludedthe enigmaticgenusPygarrhichas within the Dendrocolaptinae.Becauseits systematicpositionremainselusiveit shouldbe placedin or near the Sclerurinae and Philydorinae,perhapsas "incertaesedis." The placementof the "intermediates" withinthe Dendrocolaptinae shouldbe as follows: Dendrocincla (mostovenbird-like), followedby Sittasomus, Deconychura, Glyphorhynchus, and the "strong-billed" woodhewers.It is my opinionthat the foregoing classification wouldbestreflectanyof the alternatephylogenies of the group In addition,I wouldproposethat the familynameFurnariidaebe usedbecausethe preponderance of speciesare foundwithin the Furnariinae SUMMARY The furnariids (ovenbirds) and dendrocolaptids(woodhewers) are two very closelyrelatedgroupsof suboscine birds The groupof ovenbirds most closelyrelatedto the woodhewers is the subfamilyPhilydorinae, whichshares an almostidenticalrangewith the dendrocolaptids The philydorines are the heavy-bodied forestfurnariids,and they form the link in an almostperfect anatomical seriesgoingfrom the synallaxines and furnariinesto the woodhewers There are four generaof woodhewers, Dendrocincla,Sittasornus, Deconychura, and Glyphorhynchus, which appearto be the mostprimitive of the woodhewers(lessdivergedfrom the ovenbirdpattern), and in fact, sharemany characters with the ovenbirdsincludinga wing stripepeculiarto the furnariids These four generaare termed the "intermediates."The remainderof the woodhewers,which are called the "strong-billed"woodhewers are veryhomogeneous.The problemof paramountinterestinvolvesdecipher- ing the evolutionaryrelationships.Are the "intermediates" separateoffshootsfrom philydorineancestralstock, or are they simply woodhewers whichhave retainedmany primitivecharacterstates?The great chancefor convergence in tree-trunkforagingbirds makesdecipheringthe phylogenies very difficult Anatomicaland other charactersare evaluatedby establishing anatomicalseriesfrom non-creeping to creepingforms, and then the character statesof the "intermediates"are examined The primary assump- tion is that the woodhewersrepresentan advancedstate of derivedcharacters and that the ovenbirds'suite of charactersmore closelyresemblesthe primitivestate 66 ORNITHOLOGICAL MONOGRAPHS NO 13 The skulls of furnariids differ from those of the "strong-billed" dendro- colaptids in manycharacters.Most of the furnariidsare pseudo-schizorhinal; all of the "strong-billed" dendrocolaptids are holorhinal.A summaryof the character differencesis available in Table The ovenbird skull is, in gen- eral, a muchweakerand flexibleskull,comparedto the heavilyossifiedwoodhewerskull Most of the skullcharacterscorrelatewith the foragingbehavior and type of food taken Most of the furnariidsfeed on small insects Most of the "strong-billed"dendrocolaptids feed on medium-to-large sizedhardbackedbeetles,and on smallvertebratessuchas frogsor lizards,whichoccur on tree trunks Thesebirds may frequentlyforageby probingand prying into bark and leaf and vine clusters,etc., and somemay occasionally peck like a woodpecker.Someof the philydorinefurnariidsand all of the "intermediate"woodhewergenerapossessa mosaicof woodhewer-ovenbird characters Those philydorineswhich approachthe woodhewerskull condition are thoseheavy-bodiedforestforms which (for thosewhere informationis available) feed more in a woodhewermanner and on large prey, and may peck, pry, and probe in their feedingbehavior There is an anatomicalsequencefrom a weak, pseudo-schizorhinal skull throughthe philydorinesand "intermediates"to the strongwoodhewerskulls Both the furnariidsand dendrocolaptids have basicallya two-notched sternum,but with greatvariation Someformsshowa tendencytoward opening of the posteriorborder of the sternum, while others show a tendency toward the closingof it The furnariids show a tendencytoward an open posteriorborder of the sternum;none showsa tendencytoward its closure The "strong-billed"dendrocolaptids show a tendencytoward closure The "intermediates"are clearly furnariid-likein this character All possess twonotchedsterna,but nonewith a tendencytowardclosure,andtwo formswith a slighttendencytowardopening The hind limb bones (as expectedfrom other creepingforms) are shorter in the woodhewers than in the ovenbirds The "intermediates" are somewhat intermediate between the ovenbirds and woodhewers in these characters The distal end of the tarsometatarsus in ovenbirds differs from that in wood- hewers In the woodhewers,metatarsalI is short, correspondingto a short hallux;the amountof separationbetweenthe condylesis great;and the trochlea for digit III is deeply excavated.The "intermediates"are betweenthe ovenbirds and woodhewers in all of these characters It is of interest here that some of the tree-trunk foragingfurnariids are close to the woodhewer condition,indicatingconvergence.The femur of woodhewershas a foramen or many small foraminain the proximalend; ovenbirdsgenerallylack the foramen It is presentin Glyphorhynchus(nearly absentin Dendrocincla), but absentin the other "intermediates."The proximalend of the tibiotarsus 1973 EVOLUTION IN OVENBIRDS AND WOODHEWERS 67 in the woodhewers showsexpansionof the area for the origin of the main extensor muscle of the toes Most of the "intermediates" are woodhewer-like in thesecharacters,but Dendrocinclais somewhatintermediate,and Xenops, a philydorinefumariid, is very woodhewer-like in its tibiotarsus.The feet (digits) of woodhewers differ from thoseof ovenbirdsin havingdigitsIII and IV nearly equalin length,and this lengthis greaterthan that of digit II Also, the three anteriortoesare fusedexteriorlyfor the entirelengthof their basalphalanges.The woodhewerhallux is short The ovenbirdfoot is, for the mostpart, the typicalpassefineanisodactyl foot Althoughwoodhewers and ovenbirdsare generallyseparableby the charactersof the feet, there are someintermediates, andmanytree-trunkforagingbirds(includingovenbirds) approachthe woodhewercondition Ames (1971) reportedthat the syringesof the ovenbirdsand woodhewers are very similar, but differ betweenthe two groups The "intermediates" (Deconychurawas not examined) possessthe woodhewertype of syrinx, but Geositta(a typicalfurnariidin other characters)possesses the woodhewertypeof syrinx The disc (acrylamide) electrophoretic patternsof hemoglobinin ovenbirds are differentfrom thosein woodhewers.Of the "intermediates,"Glyphorhynchusshowsa hemoglobinpatternidenticalto that of the woodhewers; Sittasomus andDeconychurashowpatternslike eachother,but differentfrom both the woodhewerand ovenbirdpatterns;and Dendrocincla(anabatina) showsa patternidenticalto that of the ovenbirds A computerclusteranalysiswas performedto determinequantitativelythe overallsimilarityof selectedOTUs The Prim Network (Fig 19) confirms the positionof the "intermediates." There are two possiblephylogenies for the woodhewers.The woodhewers may be of multiple origin from philydorine-likeancestors,or monophyletic,if the "intermediates" are simplyforms which have retainedmany primitivecharacters A behavioralmodel involvingcompetitionfor feedingspacein mixed speciesforagingflocksmay be a possibleexplanationfor the origin of treetrunk foragingbehavior 10 Classifications shouldbestreflectphylogenies, andin linearshouldpreferably beginwith the more primitive forms (where known) and end with the more specialized.None of the existingclassifications accomplishes this end, thoughSclater'sclassification certainlyapproximates a primitiveto specialized scheme(see Table 4) I would recommendfollowing the classificationof Sclaterat the familial and subfamiliallevels However,I would stronglyrec- 68 ORNITHOLOGICAL MONOGRAPHS NO 13 ommendthat the more generalizedSynallaxinaeprecedethe more specialized (primarilyterrestrialor semi-terrestrial) Furnariinae,andI wouldadditionally recommendgenerictransfers(now commonlydone) as follows Margarornis, Premnornis,andPremnoplexare ovenbirdsand shouldbe transferredprobably to the Synallaxinae.Sclaterhad includedthe margarornithines within the Dendrocolaptinae.Pygarrhichas(which Sclaterhad alsoincludedwithin the Dendrocolaptinae)shouldbe placedin or near the Sclerurinaeand Philydorinae as "incertaesedis";its systematicpositionremainselusive And finally, the sequencewithin the Dendrocolaptinae shouldbe: Dendrocincla, Sittasomus,Deconychura, and Glyphorhynchus,followed by the "strongbilled"woodhewers Finally,thefamilynameFurnariidaeis mostappropriate for theovenbird-woodhewer assemblage LITERATURE CITED AMES, P.L 1971 The morphology of the syrinx in passerinebirds Bull Peabody Mus Nat Hist., Yale Univ., No 37: 1-194, 21 pls BEI•I•A•a•,F E 1898 The structure and classification of birds Longmans, Green and Co., London BOCK,W.J 1960 The palatine processof the premaxilIa in the Passeres Bull Mus Comp Zool., 122: 361-488 BOCK,W J 1963 Relationshipsbetween the birds of paradise and the bowerbirds Condor, 65: 91-125 Boca:,W.J 1964 Kinetics of the avian skull Jour Morph., 114: 1-41 BoCK,W J., ANI• W D M•LLER 1959 The scansorialfoot of the woodpeckers,with comments on the evolution of perching and climbing feet in birds Amer Mus Novit., No 1931: 1-45 Dnws, B.J 1964 Disc electrophoresisII method and application to human serum proteins Ann New York Acad Sci., 121: 404-427 DESBOROUGH, S., ANDM R IRWIN 1966 Additional variation in serum proteins in Columbidae Physiol Zool., 34(1): 66-69 E•wnm•s, A W F., nNI• L L CnWL•-SFogzA 1964 Reconstruction of evolutionary trees Syst.Assoc.PubI., 6: 67-76 ENOg•S,W.L 1940 Structural adaptationsin thrashers (Mimidae: genusToxostoma) with commentson interspecificrelationships Univ California Publ Zool., 42: 341-400 FARRIS,J.S 1967 The meaning of relationship and taxonomic procedure SystematicZool., 16: 44-51 FEDUCCIA,J.A 1967 The amphirhinal condition in the Passeriformes Wilson Bull., 79: 453-455 Fgl•t•cc•n, J.A 1970 Natural history of the avian families Furnariidae and Dendrocolaptidae J Grad Res Center, Southern Methodist Univ., 38: 1-26 Fgl•t•cc•n, A 1972 Variation in the posterior border of the sternum in some treetrunk foraging birds Wilson Bull., 84: 315-328 F'I.•BRINGER,M 1888 Untersuchungenzur Morphologie und Systematik der Vogel Vol I, T J Holkema, Amsterdam GARROD,A.H 1873 On the value in classificationof a peculiarity in the anterior margin of the nasal bones in certain birds Zool Soc London, Proc 1873: 3338 1973 EVOLUTION GAllROD,A.H IN OVENBIRDS AND WOODHEWERS 69 1877 Notes on the anatomy of passerinebirds Part II Zool Soc London, Proc 1877: 447-453 HELLMAYR,C.E 1925 Catalogue of birds of the Americas and adjacent islands Part Field Mus Nat Hist., publ 234, Zool Ser., No 13, 390 pp HOFER, H 1954 Neuere Untersuchungenzur Kipfmorphologie der Vi3gel Acta XI Congr Internat., Ornith., pp 104-137 JoLLIE,g 75: 1958 Commentson the phylogenyand skull of the Passeriformes.Auk, 26-35 KrrTo, G B., ANDA C WILSON 1966 Evolutionof malate dehydrogenase in birds Science, 153: 1408-1410 KLIJGE, A G 1969 The evolution and geographical origin of the New World Hemidactylus mabouia-brookii complex (Gekkonidae, Sauria) Misc Publ Mus Zool., Univ Michigan, No 138:78 pp MAYR, E., AND D AM•ON 1951 A classification of Recent birds Amer Mus Novit.,No ORNSTEIN, L 1496: 1-42 1964 Disc electrophoresis I background and theory Ann New York Acad Sci., 121: 321-349 PETERS,J.L 1951 Check-list of birds of the World Vol Harvard Univ Press, Cambridge, Massachusetts.Pp i-x, 1-318 RICHARDSON, F 1942 Adaptive modifications for tree-trunk foraging in birds Univ California Publ Zool., 46: 317-368 PRIM, R C 1957 Shortest connecting networks and some generalizations Bell Syst Tech Jour., 36: 1389-1401 RIDGWA¾, R 1911 The birds of North and Middle America Part U.S Natl Mus Bull., No 50, pp i-xxiii, 1-859 SCLATER, P.L 1890 "Catalogue of birds in the British Museum." Vol XV, London SIBLEY,C.G 1970 A comparativestudyof the egg-whiteproteinsof passerinebirds Bull Peabody Mus Nat Hist., Yale Univ., No 32: 1-131 SoK•L, R R., ANDP H A SNEATH 1963 Principles of numerical taxonomy W H Freeman and Co., San Francisco and London STORER,R.W 1960 The classification of birds Pp 57-91 in Biology and com- parativephysiologyof birds, I (A J Marshall, ed.) AcademicPress,New York STOLPE,M 1932 Physiologisch-anatomische Untersuchungenuber die hintere Extremitat der Vogel Journ fi•r Ornith., 80: 161-247 STRESEMANN, E 1927-1934 Aves in Handbuch de Zoologie, Vol (Part 2) (W Kukenthal und T Krumbach, eds.) Walter de Gruyter, Berlin VON IHER•N•, H 1915 The classificationof the family Dendrocolapidae.Auk, 32: 145-153 WETMORE,A 1951 A revisedclassificationfor the birds of the world Smithsonian Misc Coil., 117, No 4, 22 p WILLIS, E O 1966 Interspecificcompetitionand the foraging behavior of Plainbrown Woodcreepers.Ecology,47: 667-672 Z•Jo,G.R 1971 Buoyancy,locomotion,morphologyof the pelvicgirdle and hindlimb, and systematics of cryptodiranturtles Misc Publ Mus Zool., Univ Michigan, No 142: 1-98 Z•JsI,R.L 1962 Structuraladaptationsof the head and neck in the Black Skimmer Publ Nuttall Ornith Club, No 3, viii q- 101 pp Z•JsI,R.L 1967 The role of the depressormandibulaemusclein kinesisof the avian skull Proc U.S Natl Mus., 123: 1-28 ORNITHOLOGICAL MONOGRAPHS No A Distributional Study of the Birds of British Honduras, by Stephen M Russell 195 pp., color plates 1964 Price $4.50 ($3.60 to AOU members) No A ComparativeStudy of SomeSocialCommunicationPatternsin • the Pelecaniformes, by Gerard Frederick van Tets 88 pp., text figures 1965 Price $2.00 ($1.60 to AOU members) No The Birds of Kentucky, by Robert M Mengel Cloth bound, xiv + 581 pp., color plates plus text figures and vignettes 1965 Price $10.00 ($8.00 to AOU members) No Evolution of SomeArctic Gulls (Larus): an Experimental Study of Isolating Mechanisms,by Neal Griffith Smith 99 pp., 62 text figures 1966 Price $2.50 ($2.00 to AOU members) No A ComparativeLife-historyStudyof Four Speciesof Woodpeckers, by Louise de Kiriline Lawrence 156 pp., 33 text figures 1967 Price $3.75 ($3.00 to AOU members) No Adaptationsfor Locomotionand Feeding in the Anhinga and the Double-crested Cormorant, by OscarT Owre 138 pp., 56 text figures 1967 Price $3.50 ($2.80 to AOU members) No A Distributional Surveyof the Birdsof Honduras,by BurrL Monroe, Jr 458 pp., 28 text figures, color plates 1968 Price $9.00 ($7.20 to AOU members) No An Approachto the Studyof EcologicalRelationshipsamongGrassland Birds, by John A Wiens 93 pp., 30 text figures 1969 Price $2.50 ($2.00 to AOU members) No Mating Systems, SexualDimorphism,and the Role of Male North American PassefineBirds in the Nesting Cycle, by JaredVerner and Mary F Willson 76 pp 1969 Price $2.50 ($2.00 to AOU members) No 10.The Behaviorof SpottedAntbirds, by EdwinO Willis,vi + 162pp., color plates,27 text figures 1972 Price $6.00 ($4.75 to AOU members) No 11.Behavior,Mimetic Songsand SongDialects,and Relationshipsof the Parasitic Indigobirds (Vidua) of Africa, by Robert B Payne, vi + 333 pp., colorplates,50 text figures,40 audiospectrographs 1973 Price $8.00 ($6.40 to AOU members) No 12.Intra-island Variation in the Mascarene White-eye Zosterops borbonica, by Frank B Gill, vi + 66 pp., color plate, 31 text figures 1973 Price $2.00 ($1.60 to AOU members) No 13.Evolutionary Trends in the Neotropical Ovenbirds and Woodhewers, by Alan Feduccia,iv + 69 pp., 20 text figures 1973 Price $2.00 ($1.60 to AOU members) Like all other AOU publications,OrnithologicalMonographs are shipped prepaid Make checkspayable to "The American Ornithologists'Union." For the convenienceof those who wish to maintain complete sets of Ornithological Monographsand to receivenew numbersimmediatelyupon issue,standingorders will be accepted Order from: Butt L Monroe, Jr., Treasurer, American Ornithologists' Union, Box 23447, Anchorage,Kentucky 40223 ... NEOTROPICAL AND OVENBIRDS WOODHEWERS BY ALAN ORNITHOLOGICAL FEDUCCIA MONOGRAPHS PUBLISHED THE AMERICAN BY ORNITHOLOGISTS' 1973 NO UNION 13 ORNITHOLOGICAL MONOGRAPHS This series,publishedby the American... Copiesof Ornithological Monographsmay be orderedfrom the Treasurer of the AOU, Burt L Monroe,Jr., Box 23477, Anchorage,Kentucky40223 (See price list on insideback cover.) Ornithological Monographs, ... schizorhinal(see Garrod, 1877), was later recognizedas not homologousto the conditionin other ORNITHOLOGICAL MONOGRAPHS NO 13 schizorhinalbirds (charadriiform birds, etc.), and F'tirbringer(1888) proposedthat