Pale-Billed Woodpeckers Robbed of Nest Hole by Collared Aracaris

774 General Notes [Auk, Vol. 94 TABLE 1 DATA ON 3 PALE-BILLED WOODPECKER NESTS AND 1 LINEATED WOODPECKER NEST AT TIKAL IN JANUARYAND FEBRUARY1976 Nesting pairs Comparisonswith Parameters A B C 1 nest of D. lineatus Location of nest Dead stub Dead stub Bole of living tree, Dead stub; part of in forest edge of forest edge of forest living tree. In open. Height above ground 3 m 9.5 m 10 m 9 m Nestlings 1 Nestling Not seen 1 Nestling Nest excavation completed and copulations begun. Date fledged 25 January -- 2 February away and again on the morningafter, when I locatedit 50 m from the nesttree. The male made"kwirra" notesas if in response.When the maleflew theyoung one followed, and whenthe young one approached, the parentmoved away. Theseperformances, kept up for 20 min, appearedto be a successfuleffort of the male to lead the fledgling into the forest. Comparisonswith Lineated Woodpecker.--Likethe Crimson-crested(C. melanoleucos) (Kilham 1972, Wilõon Bull. 84: 28) the closelyrelated Pale-billedWoodpecker is syrupatticwith the Lineated Woodpecker (Dryocopuslineatus) of similar size. It would seempossible that the Campephilusspecies might compete with thelatter for nestingsites. Although my datawere limited, it did seemthat competitionwas avoided in Panamaby Lineatedsbreeding later than the Crimson-crestedWoodpeckers and choosingdifferent types of nestsites. I found much the samesituation at Tikal. In the last of Januaryand the first day of February, whenyoung from threenests of Pale-billedWoodpeckers were well developedor fledged,a pair ofLineateds (Table 1) was excavatinga nesthole and copulating.The copulationon 1 February lasted7 secand took placeon a tree 60 m from the excavation.While the excavationwas in a stub similar to thoseused by the Pale-billsit stoodmore in the openbeing surrounded, in part, by lawns and openroadways.--LAWRENCE KILHAM,Department of Microbiology,Dartmouth Medical School,Hanover, New Hampshire03755. Accepted 9 July 76. Pale-billed Woodpeckers robbed of nest hole by Collared Ara½/aris.--On 14 January 1976, whilestaying at LaSelva,a stationrun by theOrganization for TropicalStudies, Inc., in CostaPica, I found a male Pale-billedWoodpecker (Campephilus guatemalensis) excavating a nestin a stub 10m tall and 45 cm dbh. The stubhad fungalbrackets and appearedto be well rotted,for the male threw manybillfuls of sawdustfrom a hole 7 m abovethe ground.I watchedthe male excavatingfor 115rain in the morningand the femalefor 57 rain in the afternoon.Although able to getcompletely within the hole, the maleflew off at duskand did notroost there. On thenext day, heavy rains fell, andI watchedthe male excavate for 73rain in themiddle of the day. On 16January, at 0755,the pair of woodpeckers had an abortivecopulation, followed in 3 min by a full copulationlasting 7 secon a tree 50 m from the nest. The nest stub roseabove small treesin secondgrowth forest at the edgeof a field. A group of 4 Collared Ara!;ariToucans (Pteroglossus torquatus) came by frequentlyand on 14January I noticedthat onepaused 6 m away, as if watchingthe malewoodpecker excavating. My wife foundan ara!;arilooking from the nest holeat 0945 two dayslater. At 10001 waswatching as 4 ara!;ariscame to a branch7 m from the hole. First one, then a secondflew to the holeand entered,remaining inside for severalminutes. I did not seethe woodpeckersby their nest stub during the morning. Boththe male and female woodpeckers excavated briefly in theafternoon. The tappingand exchanges of intimatenotes accompanying their meetings were similar to thosedescribed (Kilham 1972, Wilson Bull. 84: 28)for the Crimson-crestedWoodpecker (C. melanoleucos),a closely related species. I returnedin thelate afternoonto seewhat bird, ara•;arior woodpecker,might roost in the hole.On arrival at 17101 foundan aca!;arilooking from the entrance.When the malePale-billed Woodpecker flew to a tree6 m away,the ara!;ariwithdrew inside. The woodpeckerslowly ascended the tree,occasionally rapping (a displacement activity).It flewaway as dusk came on 10rain later. This was the last that I sawof thewoodpeckers by the neststub. The ara•arihad taken possession of the hole, it seemed,at thetime of itscompletion, a situation previouslywitnessed for Crimson-crestedWoodpeckers and CollaredAra•ari in Panama(Kilham, ibid.). Skutch(1958, Condor 60: 201)noted that the Pale-billedand Lineated(Dryocopus lineatus) are the only October1977] GeneralNotes 775 woodpeckersproviding holes large enough for AragariToucans, among which he includes both the Collared and the similar sized Fiery-billed (P. frantzii). In his experiencearagaris only occupiedholes after the woodpeckerswere throughnesting. He describes, however,how a maleLineated guarded its nestat a time when Fiery-billedaragaris were searching for holes in the neighborhood(1969, Pacific Coast Avifauna 35: 428). Specialfeatures of my observationson two speciesof Campephiluswoodpeckers, C. guatemalensisand C. melanoleucoswere (1) that they madeno effortto eitherguard or to defendtheir nestsand (2) that the aragari took over the holesat a time when the woodpeckerswere copulatingand about to lay eggs.It would seem from these observationsthat aragaris, by disrupting the nesting of the woodpeckers,might be a factor limiting their populations.It may be, however,that the severityof competitionbetween the Campephilus woodpeckersand ara•aris is relatedto habitat.Both of theincidents witnessed were in low secondgrowth forest where dead stubs and trees suitable for nest excavationswere scarceand the toucans plentiful. In a mature forest at Tikal in Guatemala, in contrast, where I found three pairs of Pale-billed Woodpeckers feedingyoung in January 1976, suitablestubs appeared to be relativelyabundant and CollaredAragaris scarce.I saw nonewhile watchingthe woodpeckers.It is of interestfrom this point of view that Skutch (1958) statesof Fiery-billed Aragaristhat he did not find them "sleepingor breedingin the midst of intact forest."--LAWRENCEKILHAM, Departmentof Microbiology,Dartmouth Medical School,Hanover, New Hampshire 03755. Accepted 9 July 76. Some clarifications aboutRamphastos "aurantiirostris."--The toucanknown asRamphastos aurantiirostrisHarterr (1925, Nov. Zool.32: 143)has been considered similar to thesympatric R. t. tucanus exceptthat the sides of the bill arelight yellowish orange to reddishorange instead of dark red to black. Until 1975 the indicatedaurantiirostris characterhad been recordedonly from museumspecimens taken in easternVenezuela, the Guianasand northeasternBrazil. In this regard, over some15 yearsI have spent severalmonths accumulated time in easternVenezuela from where specimensthat showthis characterhave beencollected, but I have neverseen a living bird displayit. The closesthave beenindividuals of R. t. tucanus(identified by voice)with thebill colorsomewhat dusky scarlet instead of themore usual darker hue. The first publishedevidence ofaurantiirostris-like birds in life wasrecently given by Bourne(1975, Living Bird 13:102), who reported birds from Guyanawith bill "dark cadmiumorange" (as a minorityamidst birds showing "dark alizarine crimson"). Althoughmost recent publications recognize R. aurantiirostris,they usually indicate doubt (of onekind or another)about its status. Recently, Haffer (1974, Nuttall Ornithol.Club 14:291,305) indicated his belief that aurantiirostrisspecimens are "merelyparticular phenotypes of the variably red-billedtucanus popula- tion of easternand northeasternAmazonia, which in life may be lessdistinct than they are as discolored museumspecimens." He consideredthe form taxonomically invalid. Bourne (1975: 103) also considered the orange-billedbirds he observedto be only variantsof R. tucanusas they interbredwith red-billedbirds. I hope that the opinionsof Haffer and Bournewill be generallyaccepted, but asR. aurantiirostrishas shown considerablepersistence in the past, I presentthe following more recentevidence. It documents beyonddoubt that the orangebill canalso result from postmortemcolor change and also calls attention to a characterthat Harterr regardedas more important than the orange-redcolor. In July 1975, while showingsome visitors the synopticseries of the bird collectionof the Estaci6n Bio16gicade RanchoGrande in Venezuela,I noticedthat amongthe R. t. tucanuswere two specimensof "aurantiirostris."Circumstances prevented closer investigation at thetime, butI tookcolor transparencies of thesetwo specimens.Examination in December1975 revealed the followingcolors for the normallydark red areasof the sidesof the bill of thesebirds. The colorsare approximatedfrom Smithe(1975, Naturalist's Color Guide, Amer. Mus. Nat. Hist.) and are capitalizedonly when usedin direct reference. EBRG #6986, •?, 27 Feb 1969,Rio Grande(ca. 20 km eastof E1Palmar), n. Bolivarstate, Venezuela. Maxilla: orangewashed with verypale gray (a slightlydull, but notdark SpectrumOrange); some scattered mottlingof lightto mediumgray, sparse on the right side, profuse on theleft. Mandible:similar except that the distalfifth of the areais dull scarlet,and thiscolor extends posteriorly in a thin line borderingthe blackish areas of the tomium and the gonys. EBRG #6985, c•, samedate and locality.Maxilla: yellowishorange washed with very palegray (approxi- matingBuff but somewhatlighter and moreorange); some mottling of light to mediumgray relatively sparse on both sides.Mandible: yellowish orange so thoroughly masked by dark gray as to resultin a yellowed DuskyBrown with onlyscattered flecks of the palebase hue showing through; in theproximal region on the left side is one large spot of color as on the maxilla. .

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