January1986] ShortCommunications 227 shortcomingof the modal method is that it estimates -, & J. T. EMLEN. 1966. A technique for record- only the direction of activity and gives no indication ing migratory orientation of captive birds. Auk of the scatterof hopping, whereas the traditional 83: 361-367. method indicates the degree of concentration of a HAMILTONßW. J., III. 1966. Analysis of bird navi- bird's hopping (mean vector length, r). This is not gationexperiments. Pp. 147-178in Systemsanal- often a major problem becausemost recent studies ysis in ecology (K. E. F. Watt, Ed.). New York, have relied on second-orderanalyses of mean direc- Academic Press. tions that ignore the mean vector lengths. Indeed, at MARDIA, K. V. 1972. Statistics of directional data. this point the biological meaning of the dispersion New York, Academic Press. of a bird's hoppingactivity is not clearand is in part MOORE,F. R. 1985. Individual variability in the mi- a reflection of the idiosyncraciesof individual birds gratory orientation of the Savannah Sparrow, (Wiltschko and Wiltschko 1978, Moore 1985). Passerculussandwichensis. Z. Tierpsychol. 67: 144- 153. LITERATURE CITED RABOL,J. 1969. Orientation of autumn migrating Garden Warblers (Sylvia borin) after displace- BATSCHELET,E. 1978. Second-order statistical anal- ment from western Denmark (Blfivand) to east- ysisof directions.Pp. 3-24 in Animal migration, ern Sweden (Ottenby). A preliminary experi- navigation, and homing (K. Schmidt-Koenig and ment. Dansk Ornithol. Foren. Tids. 63: 93-104. W. T. Keeton, Eds.).Berlin, Springer-Verlag. 1970. Transformationof colour degreesto 1981. Circular statisticsin biology. New number of jumps using the Emlen orientation York, Academic Press. technique. Dansk Ornithol. Foren. Tids. 64:118- BINCMAN,V. P. 1983. Importance of earth's mag- 126. netism for the sunset orientation of migratory WILTSCHKO, R., & W. WILTSCHKO. 1978. Relative im- naive SavannahSparrows. Monit. zool. Ital. 17: portanceof starsand the magneticfield for the 395-400. accuracyof orientation in night-migrating birds. ., & K. P. ABLE. 1979. The sun as a cue in the Oikos 30: 195-206. orientation of the White-throated Sparrow, a WILTSCHKO,W., • K. H. SCHMIDT. 1974. Direcciones nocturnal migrant. Anim. Behav. 27: 621-622. preferencialesde migrantesnocturnos (Passeres) CHERRY,J.D. 1984. Migratory orientation of Tree por Almerla. Ardeola 20: 127-140. Sparrows.Unpublished M.S. thesis,Albany, State ß & R. WILTSCHICO.1972. Magnetic compass Univ. New York. of EuropeanRobins. Science 176: 62-64. EMLEN,S.T. 1969. The development of migratory orientation in young Indigo Buntings. Living Received4 February1985, accepted 26 August1985. Bird 8: 113-126. Notes on the Plumagesof the Paramo Seedeater(Catamenla homochroa) ROBERT W. DICKERMAN CornellUniversity Medical College,New York, New York 10021 USA, and AmericanMuseum of Natural History,New York,New York 10024USA Many species of nonpasserine birds, especially ually dimorphic,but that there are severalplumage among the Ciconiiformes, Falconiformes, and Cha- stages.Geographic variation could not be evaluated radriiformes, exhibit three or more successive,pre- until the plumageswere identified so that compara- definitive, full basic plumages. Comparable se- ble age classescould be compared. quencesare little known among Passeriformes;for I obtained 107 specimensof C. homochroaon loan one example,Parkes and Humphrey (1963) described (seeAcknowledgments) for comparisonwith the 65 four age classesin male Yellow-backed Tanagers specimensin the collection of the American Museum (Hemithraupisfiavicollis), and I have found four age of Natural History (AMNH). Included in the series classesin male Altamira Orioles (Icterusgularis; Dick- of C. homochroawere 5 specimensof oreophila,the erman MS). subspeciesfrom Cerro Santa Marta, Colombia. For The acquisitionof freshly collected and correctly the purposesof this study,all Andean specimensof aged specimensof the PararnoSeedeater (Catamenia C. homochroa,from Merida, Venezuelato Chuspipata, homochroa)from Cerro Neblina in extreme southern Bolivia, were combined and segregatedby sex, and Venezuela stimulated me to review the geographic thence by plumage stage,regardless of date of col- variation in the species.In preliminary studiesit was lection. Similarly, all specimensof C. h. duncani,the immediatelyobvious that the speciesis not only sex- subspeciesfrom the Pantepui region of southern 228 ShortCommunications [Auk, Vol. 103 TABLE1. Comparisonof postjuvenilebasic plumages of male Catameniahomochroa homochroa. Capitalized color nameswith numbersindicate direct comparisonwith Smithe's(1975, 1981)"Naturalists' Color Guide." First basic Second basic Definitive Crown Prout's Brown (121A) to Sepia(I 19), streakingbe- BlackishNeutral Gray (82) Sepia (219), weakly comes evident in some to black, unstreaked even streakedwith dusky worn specimens when worn Interscapular Prout's Brown (121A) to Hair Brown (119A) to Van- Vandyke Brown (121) to area Sepia (219), strongly dyke Brown (121), weakly BlackishNeutral Gray streaked streaked, more evident in (82), streakingobsolete worn specimens when worn Rump Prout's Brown (121A) to Brownish Olive (29) to Ol- Sepia (119) Dark Brownish Olive ive Brown (28) (129) Throat Buffy GrayishHorn (91) Glaucous (79) to Dark Neu- Dark Neutral Gray (83) tral Gray (83) Flanks BrusselsBrown (121B) to Dark Brownish Olive (121) Vandyke Brown (221) Verona Brown (223B), weakly streaked Belly Cinnamon (39) to Buff Cinnamon (39) to Clay Col- Glaucous(79) (124) ored (123B) Crissum KingfisherRufous (340) Kingfisher Rufous(340) to Chestnut(32) MahoganyRed (132B) Specimens AMNH 117056, 124964, AMNH 130474, 170034, AMNH134129, 820632 used 820576 180700, 180699 Venezuela,were segregatedby sexand plumagestage. within each successivestage, followed by a shift in Unfortunately,few specimensin molt are available. color or pattern in the next plumage group. Speci- Four plumageswere identified and are described menstaken year-roundare not availablefrom a sin- below for each sex of C. homochroa, based on com- gle locality,or even from adjacentranges, and be- parisonsof the changesin wear from fresh to worn causeof the obviousvariation in phenologyover the TABLE2. Comparisonof postjuvenilebasic plumages of femaleCatamenia homochroa homochroa. First basic Second basic Definitive Crown Raw Umber (223) to Fus- Hair Brown (119A) to Fus- Dusky Brown (119) to Black- cous(21), heavily cous(21), heavily ish Neutral Gray (82), streaked streaked streakingobsolete Interscapular Hair Brown(119A), heavi- Prout'sBrown (121A), Vandyke Brown (121) to area ly streaked heavily streaked BlackishNeutral Gray (82), streaking obsolete Rump Olive Brown (28) to Prout's Brown (121A) Olive Brown (28) to grayish Brownish Olive (29) Hair Brown (119A) Throat and Glaucous(80) to Light Light Drab (119C) to Glaucous(79) to brownish breast Drab (119C),streaking BrownishOlive (29) on Light Neutral Gray (85), obsolete breast,throat weakly unstreaked streaked Flanks BrusselsBrown (121B)to Clay-colored(26) to Olive SmokeyGray (44) to Dark Prout's Brown (121A) Brown (28), streakingob- Brownish Olive (129), solete grayer when worn Belly Clay-colored(132B) PaleHorn (92) to Tawny Tawny (38) to Kingfisher Olive (223D) Rufous (240) Crissum Tawny (38) to Kingfisher Tawny (38) to Kingfisher Tawny (38) to Kingfisher Rufous(240) Rufous(240) Rufous (240) Specimens AMNH 180701,180702, AMNH 134132,134133, AMNH 134134, 170036; CM a used 180703, 112727 134135 70469, 70704 ' CM = CarnegieMuseum of Natural History. January1986] ShortCommunications 229 Fig. 1. Dorsalview and ventral view Catameniahomochroa homochroa. Left to right, males:juvenile plumage AMNH 134128 Colombia; first basic AIVlNH 124967 Ecuador; second basic AMNH 180705 Ecuador; definitive AMNH 820578Peru. Females:juvenile plumageAMNH 820577,first basicUSNM 375405Colombia; second basic USNM 375410 Colombia; definitive AMNH 1314134 Colombia. extended range of the species,specimens could not and 2. However, the three age groupsare most dra- be comparedbased on dates of collection. Because matically seen among specimens in worn plumage there was no evidenceof extensive(if any) prealter- (Fig. 1). In all three speciesof the genus,there are hate molt that would be indicatedby differentialwear two general trends in the plumage succession:the of parts of the body in worn specimens, the four reductionof streakingfrom the juvenile to the defin- stagesmay be called juvenile, first and secondbasic, itive plumage,and an increasein grayness. and definitive basicplumages. There appearedto be no sexualdimorphism in the Having determined the plumage sequenceof C. heavily streaked juvenile plumage. Juvenile nomi- homochroa,I examined the specimensof C. inornata nate homochroaare paler and lessheavily, althoughnot and of C. analisin the AMNH, supplementedby 19 lessextensively, streaked than are juvenile duncani. specimensof females and males in the more confus- When specimensof C. homochroawere segregated ing striped plumages obtained on loan. Sufficient by age and sex,and when recently taken (post-1960) males of C. inornata minor were available to delimit specimenswere separatedfrom those taken earlier, four plumage stagessimilar to those in C. homochroa. there were no comparablegroups with a sufficient In male C. analisanaloides (the latter supplemented number of specimensin unworn plumage to be able with specimensof the subspeciesanalis and alpicain to determine the extent of foxing over time, or the striped plumages), I