PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON lll(2):420-424. 1998. Taxonomic notes on hummingbirds (Aves: Trochilidae). 1. Eriocnemis dyselius Elliot, 1872 is a melanistic specimen of Eriocnemis cupreoventris (Fraser, 1840) Gary R. Graves DepartmentofVertebrateZoology,NationalMuseumofNaturalHistory,SmithsonianInstitution, Washington,D.C. 20560,U.S.A. — Abstract. Eriocnemis dyselius Elliot, 1872 is hypothesized to be a mela- nistic specimen of Eriocnemis cupreoventris (Fraser, 1840), a puffleg hum- mingbirdrestrictedto the Andes Mountains ofColombiaandVenezuela. Amongthefamiliesofbirds,thesystem- mountwithglasseyes, is adultasjudgedby atics of the Trochilidae are the most con- the lack ofstriations on the maxillary ram- fused, inabsolutenumbers,byhybrids, ge- phothecum (see Ortiz-Crespo 1972). Previ- netic variants, and the problems associated ouslyhousedinboththeBourcierandElliot withtaxadescribedfromuniquespecimens collections (see Greenway 1978), the speci- (e.g., Berlioz & Jouanin 1944; Banks & menisnowcataloguedintheAmericanMu- Johnson 1961; Greenway 1978; Bleiweiss seum ofNatural History (AMNH 38452). I 1988; Graves 1990, 1993, 1996, 1997a, studiedthespecimentakingtheapproachout- 1997b; Hinkelmann et al. 1991). One such lined in Graves (1990) and Graves & Zusi questionable taxon is Eriocnemis dyselius (1990). In determining the scope ofthe spe- Elliot, 1872 a puffleg hummingbird ofin- cies pool to be investigated, Elliot's (1872: determinate origin. Salvin (1892:369) sug- 294) descriptionoffers littleguidance: gested that the black-plumaged specimen "Four specimens, precisely alike, were, was "perhaps amelanismofE. cupreiven- asIwasinformed,containedinthesmall tris," an inhabitant of forest borders and collection of birds from which my ex- shrubby slopes (1950-3000m)oftheVen- amplewastaken;and, althoughnolocal- te1hz9eu8e6l,CaonFljAoenlmddbseiasan&andAKnrtadhbeebsEeas(1tH9ei9rl0nt)yC.orS&daillvBliernroadwiondf iistytwheashagbiivteant,oiftitshesuspppeocsieesd."thatEcuador not elaborate on this proposal. Subsequent The existence of four similar specimens of authors (Cory 1918, Berlioz & Jouanin unknownorigin shouldnotbe interpretedas 1944,Peters 1945,Greenway 1978,Fjeldsa evidence ofa differentiatedpopulation. Mil- & Krabbe 1990) agreed with Salvin but linery dealers inthe 19thcentury sortedand likewise provided no further support for high-gradedshipmentsofhummingbirdskins this hypothesis. Consequently, the taxono- for unusual specimens to offer to collectors my ofE. dyselius is still uncertain. Here I of natural history specimens. Although the present evidence that supports Salvin's circumstancesofElliot'sacquisitionofE.dy- (1892) conjecture that the holotype of E. seliusareunknown,thefourblack-plumaged dyselius is a melanistic specimenofErioc- specimens could have been gleaned from nemis cupreoventris (Fraser, 1840). commercial lots consisting of tens of thousandsofspecimens(Doughty 1975).For Materials andMethods the purpose of analysis, the holotype ofE. The unsexed holotype of Eriocnemis dy- dyselius may have originated anywhere in selius (Fig. 1), apartially relaxedtaxidermy northwestern South America (see Berlioz & VOLUME 111.NUMBER2 Fig. HolotypeofEriocnemisdyseliusElliot, 1872(AMNH38452). Jouanin 1944), a region inhabited by more member of Eriocnemis. I took standard than 150 species ofhummingbirds (Hilty & measurements (rounded to the nearest 0.1 Brown 1986, Graves 1990). mm) of adult male and female specimens I considered Salvin's hypothesis as the ofEriocnemiscupreoventris, E. nigrivestis, most likely, apriori. The possibilityofhy- andE. vestitus (thethree speciesmostsim- bridization wasjudgedtobe negligiblebe- ilarin size and shapetotheholotypeofE. cause the plumage of E. dyselius is sub- dyselius) with digital calipers: wing chord; stantiallydarkerandlessreflectivethanthat lengths ofrectrices (frompointofinsertion of any potential parental species in north- of central rectrices); and bill length (from western South America (i.e., Coeligena anterior extension of feathers) (Table 1). prunellei, Eriocnemis nigrivestis, Helian- Color comparisons were made under natu- geluszusii, H. regalis). ral light; theplumage was examinedunder Thedownytibialpuffs andbodypropor- 10X magnification (Appendix). tions of E. dyselius clearly mark it as a I used principal components analysis PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON — Table 1. Rangesandmeans(± standarddeviation)ofmeasurements(mm)ofEriocnemiscupreoventris,E. vestitus, andthetypespecimenofEriocnemisdyseliusElliot, 1872. cupreoventris vestitus 66 99 66 99 (n=15) (/>=6) (n=15) («=11) AMNH38452 Wingchord 59.6-63.8 57.2-60.7 57.8-61.3 54.7-59.4 58.8 61.6 ± 1.3 58.8 ± 1.1 59.4 ± 1.1 57.7 ± 1.4 Billlength 16.6-18.6 17.0-19.6 15.9-18.8 17.4-19.2 17.5 17.8 ± 0.5 18.5 ± 1.0 17.5 ± 0.8 18.5 ±0.5 Rectrix 1 24.5-28.2 24.6-26.6 26.2-29.7 29.7-32.8 26.9 26.4± 1.1 25.8 ±0.7 28.4± 1.1 31.1 ±0.9 Rectrix2 26.9-31.2 26.1-28.2 28.0-31.5 31.3-35.1 29.8 28.6 ± 1.3 27.4 ±0.8 29.9 ± 1.1 32.9 ± 1.1 Rectrix3 31.9-36.6 30.7-33.3 31.1-35.3 33.5-37.7 34.6 33.8 ± 1.5 32.1 ±0.9 33.1 ± 1.4 35.9 ± 1.3 Rectrix4 36.9^12.4 34.8-38.5 35.3-39.7 35.9-41.0 37.9 39.5 ± 1.8 37.0 ± 1.3 37.9 ± 1.5 38.9 ± 1.5 Rectrix5 40.4^6.3 36.0-40.1 40.6^15.3 37.6^12.2 39.5 42.9 ± 1.7 38.6 ± 1.6 42.7 ± 1.4 39.7 ± 1.5 Allmeasurementsonleftside. (PCA) on log, transformed measurements lacks glittering iridescence, an observation to reduce the dimensionality of data. Un- consistentwiththehypothesisofmelanism. rotated principal components were extract- Althoughmelanismisthoughttooccurata ed from covariance matrices (Wilkinson verylowfrequencyintheTrochilidae(e.g., 1989). Factor scores were projected on a Salvin 1892, Greenway 1978), the fine bivariateplottoillustratetherelationshipof structureofmelanisminhummingbirdshas rectricial measurements inEriocnemis (Ta- not been formally investigated, and I will ble 2, Fig. 2). Forbrevity, the holotype of only briefly address the topic here. Irides- E. dyseliuswillbereferredtoasdyseliusin cenceinhummingbirdsiscausedbythein- the remainderofthepaper. terference oflightreflectedfromtheupper and lower surfaces ofair-filledvacuoles in Results and Discussion melaningranules,whicharecloselystacked Currently recognized species of Erioc- in 7-15 layers in the outer keratin of the nemis (Sibley & Monroe 1990, Graves expandeddorsalflangesoffeatherbarbules 1996) exhibit areas ofglitteringorbrilliant (Dorst 1951, Greenewaltetal. 1960,Lucas plumagewhichprobably serveassignaling &Stettenheim1972).Perceivedcolorsvary badges during agonistic and sexual dis- according to the size of the vacuoles, the plays. The dull black plumage ofdyselius thickness ofmelanin granules, and the an- — Table2. Factorloadingsfromaprincipalcomponentsanalysis(PCA)ofrectricialmeasurementsofErioc- nemiscupreoventris,E. vestitus, andtheholotypeofEriocnemisdyseliusElliot, 1872. Variables Rectrix 1 (innermost) 0.0314 -0.0054 0.0076 Rectrix2 0.0298 -0.0035 0.0005 Rectrix3 0.0195 0.0055 -0.0102 Rectrix4 0.0093 0.0150 -0.0071 Rectrix5 0.0012 0.0228 0.0090 Percentvarianceexplained 66.2% 23.1% 8.3% VOLUME 111.NUMBER2 423 004 —A 1 thus eliminating that species as apossibili- 003 A A ^A ty- A A Feather shape ofdyseliusprovides addi- 002 &A tionalcluesastoitsidentity.Theoutermost CO 0.01 o A *Aaa.* A rceucptrreiocveesnatnridsloanrgeestsluipgphetrltyailnacrorvoerwtesrofanE.d 8< 0.00 00*> moreattenuatethanthoseofE. vestitusand -001 - Oo E. nigrivestis, although some overlap oc- -002 • ° fceuartshearmsoinngdytsheelispuesciisesm.oTshtesismhialpaertooftthhoessee -0.03 o . ofE. cupreoventris. -nnA Whenviewedhead-onunderdirectlight, -010 -005 0.00 0.05 10 015 the throat of dyselius emits a dull plum- PCA 1 beous iridescence but exhibits no evidence Fig.2. Bivariaterelationshipoffactorscores(PCA ofa centrally demarcated areacorrespond- 1 &PCA3,seeTable2)fromaprincipalcomponents ingto thegorget foundinboth sexesofE. parneaolyvseinstroifsr(edcitarimcoinadlsm:efaesmuarleemsen=tsfilolfed;Ermiaolcensem=isemcpu-- nigrivestis and E. vestitus. Eriocnemis cu- ty), E. vestitus (triangles: females = filled; males = preoventris lacks adefinedgorget. Instead, empty);andtheholotypeofEriocnemisdyseliusElliot, the entire throat and upper breast exhibits 1872(filledcircle). brilliantiridescenceinbothsexes.Thegra- dationoffeathersize,shape,andreflectivity across the throat ofdyseliusresemblesthat gleofobservation. Theintensityofcoloris ofE. cupreoventris. Moreover, the pattern enhancedby reflectance frommultiplelay- ofmelanizationindyseliuscorrespondspre- ersofgranules.Anoverabundanceandran- cisely with the distribution of iridescent dom placement ofmelanin granules in the plumage inE. cupreoventris. keratin would lead to a disarrangement of In summary, the holotype ofEriocnemis dyseliuscorrespondswellinsizetomaleE. thereflectivelayers,theabsorptionoflight, and a damping ofiridescentbrilliance. cupreoventris. Subtleties of rectrix shape, thelackofawell-developedgorget,andthe EriocnemiscupreoventrisandE. vestitus general pattern ofmelanization ofdyselius are remarkably similar in size and shape also areconsistentwithSalvin's(1892)hy- taonddmiesltianngiusitsihc.spTehceimmenesanwoubilldlbaenddiffwiicunlgt paomtphleesisoftEh.atcudpyrseeolvieunstriiss,aamnedlapnriosvtiidceenxo- lengths of the respective sexes ofthe two reasontobelievethatdyseliusrepresentsei- species differby to 3.7%. The difference ther a hybrid or a valid species. Thus, the in mean rectrix length varies from0.4% to nameEriocnemisdyseliusElliot, 1872cor- 7.5% in males and 5.1% to 20.9% in fe- rectly is placed in the synonymy ofErioc- males. Comparison of raw measurements nemiscupreoventris (Fraser, 1840). and inspection of bivariate plots of PCA variables extractedfromrectricialmeasure- Acknowledgments ments showthatdyseliusis mostsimilarin size and shape to male E. cupreoventris The critiques of Richard Banks, Tom (Table 1,Fig. 2).Thebilllengthofdyselius Schulenberg, MichaelWalters, andRichard (17.5 mm) falls outside the range ofmea- Zusisignificantlyimprovedthemanuscript. surementsforE. nigrivestis(males:n = 15; Iamgratefultothecuratorsandstaffofthe 14.4-15.8 mm, X = 15.1 ± 0.5, and fe- AmericanMuseumofNaturalHistory,New males: n = 6; 15.6-16.5 mm, X = 16.0 ± York, for permitting me to study the spec- 0.3; see measurements in Graves 1996), imen.Photographicprintswerepreparedby — 424 PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON the Smithsonian photographic services. hummingbird (Heliodoxa leadbeateri X Helian- Travel was supported by the Alexander gelusamethysticollis)fromnorthernColombia. 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ProceedingsoftheBiologicalSocietyof plumageofdyseliusisentirelyblack(withtheexception Washington 103:6-25. oftibialplumes), glossieronthecrown(bluishsheen), . 1993. Relicofalostworld: anewspeciesof withfaintgreenishreflectionsontheuppertailcovertsand sunangel(Trochilidae:Heliangelus)from"Bogo- pronounced bronzy-green reflections on the innermost ta."—Auk 110:1-8. secondaries.Sidesofthehead,lores,andauriculars,are . 1996. Diagnoses of hybrid hummingbirds aboutsamecolorasthehindneckandcrownbutlackthe (Aves:Trochilidae).2—.HybridoriginofEriocnem- bluishsheen.Dorsalbodyplumageissubtlydarkerthan issoderstromiButler. ProceedingsoftheBiolog- ventral plumage; feather bases are grayish-buff, palest icalSocietyofWashington 109:764-769. neartherachis.Thethroatlacksastructurallydemarcated . 1997a. Diagnoses of hybrid hummingbirds gorget;however,theterminaldiscsreflectafaintplum- (Aves:Troc—hilidae).3.ParentageofLesbiaortoni beous iridescence in direct light (dull black in diffuse Lawrence. ProceedingsoftheBiologicalSociety light).Thebasalmarginsofsomethroatfeathersarebuf- 110:314-319. fy-white, imparting a somewhat mottled or scaled ap- . 1997b. Diagnoses of hybrid hummingbirds pearancetothethroat.Undertailcovertsareblackwitha (Aves:Trochilidae).—4.HybridoriginofCalothor- bluishsheen.Primariesaredullblackbutpalerthanthe axdecoratusGould. ProceedingsoftheBiolog- dorsalbody plumage. Rectrices areglossybluish-black icalSociety 110:320-325. on the dorsal andventral surfaces.Thewell-developed , & R. L. Zusi. 1990. An intergeneric hybrid tibial "puffs"arewhite.