BEHAVIOR, MIMETIC SONGS AND SONG DIALECTS, AND RELATIONSHIPS OF THE PARASITIC INDIGOBIRDS (VIDUA) OF AFRICA ROBERT B. PAYNE ORNITHOLOGICAL MONOGRAPHS NO. 11 PUBLISHED BY THE AMERICAN ORNITHOLOGISTS' UNION 1973 BEHAVIOR, MIMETIC SONGS AND SONG DIALECTS, AND RELATIONSHIPS OF THE PARASITIC INDIGOBIRDS ('?IDU..4,) OF AFRICA ORNITHOLOGICAL MONOGRAPHS This series,published by the American Ornithologists'Union, has been establishedfor major paperstoo long for inclusionin the Union's journal, The Auk. Publicationhas been made possiblethrough the generosityof Mrs. Carll Tucker and the Marcia Brady Tucker Foundation, Inc. Correspondenceconcerning manuscripts for publicationin the series shouldbe addressedto the incomingEditor, Dr. John W. Hardy, Moore Laboratoryof Zoology,Occidental College, Los Angeles,California 90041. Copiesof OrnithologicalMorrographs may be orderedfrom the Treasurer of the AOU, Burt L. Monroe, Jr., Box 23447, Anchorage,Kentucky 40223. (See price list on inside back cover.) OrnithologicalMonographs, No. 11, vi + 333 pp. Editor, Robert M. Mengel Editorial Assistant, James W. Parker IssuedJanuary 31, 1973 Price $8.00 prepaid($6.40 to AOU Members) Library of CongressCatalogue Card Number 73-75355 Printedby the Allen Press,Inc., Lawrence,Kansas 66044 Erratum. For a time it was hoped that publicationof OrnithologicalMonographs No. 11 would occur in 1972, the year that appearson the running headsthroughout. Publica- tion in 1972 was not realized, however,and through one of thosenoxious oversights that plague the publication processthe entire work had been printed before the failure to change the running heads was detected.--Ed. G ' I H J Breeding plumages of the males of ten kinds of indigobirds. A, Vidua chalybeata chalybeata, form "aenea" (FMNH 278472, Richard-To!l, Senegal); B, V. c. amaurop- teryx ( RBP 4469, Sabi Valley, Rhodesia); C, V. c. ultramarina (FMN H 204118, Mojjio, Ethiopia): D. l/. ]unerea codringtoni (RBP 4437. Penhalonga-Umtali. Rhodesia): E, l/. 1. !usitensisssp. nov. (RBP 4575, Lusitu River, Rhodesia); F. V. 1. [unerea (RBP 4424, 6 mi. E. Tzaneen, Transvaal); G, V. wilsoni, form "nigeriae" (RBP 4937, Panshanu Pass, Nigeria); H, l/. wilsonL form "camerunensis" (RBP 4855, Zaria, Nigeria); I, l/. wilsoni, form "wilsoni" (RBP 4960, Zaria, Nigeria); J, V. purpurascens (RBP 4419, Merensky Reserve, Transvaal). BEHAVIOR, MIMETIC SONGS AND SONG DIALECTS, AND RELATIONSHIPS OF THE PARASITIC INDIGOBIRDS (VIDUA) OF AFRICA ROBERT B. PAYNE ORNITHOLOGICAL MONOGRAPHS NO. 11 PUBLISHED BY THE AMERICAN ORNITHOLOGISTS' UNION 1973 TABLE OF CONTENTS INTRODUCTION .................................................................................................................... ACKNOWLEDGMENTS ....................................................................................................... 4 ITINERARY................................................ z........................................................................ 7 BREEDING BEHAVIOR OF INDmOBIm)S ................................................................................ 9 Social Behavior and Mating Systems...................................................................... 10 Courtship Behavior ................................................................................................ 29 BROOD PARASITISM AND THE INTERACTIONS OF INDIGOBIRDS AND FIREFINCHES ............ 39 Evidenceof Parasitismand Host Specificityin Indigobirds ................................ 39 Ecology of Indigobird Parasitism ........................................................................... 42 Behavioral Interactions Between Indigobirds and Firefinches ........................... 44 Mimicry of Eggs and Young .................................................................................... 52 VOCALIZATIONS OF FIREFINCHES AND THEIR MIMICRY BY THE INDIGOBIRDS ................ 61 Firefinch Vocalizations ............................................................................................. 62 Vocal Mimicry in Indigobird Song .......................................................................... 94 Discussion ................................................................................................................. 101 NONMIMETIC VOCALIZATIONS AND SoNG DIALECTS ........................................................ 111 Chatters ..................................................................................................................... 129 Complex Nonmimetic Songs ................................................................................... 131 Repertoire Size, Mating Systems,and Individual Recognition .............................. 146 Origin of Nonmimetic Songs and Song Dialects ................................................... 147 SoNG DIALECTS AND POPULATION STRUCTURE ................................................................. 155 Estimatesof Population Structure from Song Dialects in the Indigobirds .......... 156 Significanceof Population Structure ....................................................................... 158 BEHAVIORALCONTEXT OF INDmOmRD VOCALIZATIONS AND Tm• RESPONSESOF BIRDS TO SoNGS ...................................................................................................................... 160 Analysis of Song Recordings ............................................................................... 160 Behavioral Context of Songs ............................................................................. 161 Responsesof Wild Males to Recorded Songs ..................................................... 164 Responsesof Captive Female Indigobirdsto Species-and Population-specific Songs ................................................................................................................. 165 ASSORTATIVEMATING AND ISOLATING MECHANISMS ....................................................... 173 Assortative Mating ............................................................................................. 173 Breeding Biology and Potential Isolating Mechanisms ....................................... 175 DISTRIBUTION OF FIREFINCHES AND INDIGOBIRDs ................................................... 186 Southern Africa .................................................................................................... 186 East Africa ................................................................................................................ 194 North and West Africa ............................................................................................ 198 Central Africa .......................................................................................................... 205 Discussion ............................................................................................................... 207 VARIATION AND RELATIONSHIPS IN THE INDIGOBIRDS ................................................... 209 Basis of Identification and Taxonomic Allocation of Specimens ........................ 209 Analysis of Variation ....................................................................................... 211 Vidua chalybeata ........................................................................................... 218 Vidua purpurascens .................................................................................. 235 Vidua /unerea ................................................................................................. 240 Vidua wilsoni .................................................................................................. 250 The V. [unerea--V. purpurascensComplex .................................................... 263 Intergradation of V. chalybeata and Other Species ....................................... 273 Discussion ................................................................................................................ 277 THE IMPORTANCE OF SONG BEHAVIOR AND GEOGRAPHIC ISOLATION IN DIFFEREN- TIATION AND SPECIATION OF THE INDIGOBIRDS .......................................................... 280 Determination of Mating Groups by Imprinting to Host Songs ........................ 280 GeographicVariation in Behaviorand the Breakdownof ReproductiveIsolation Between Indigobirds ...................................................................................... 282 Two Models of Speciation.................................................................................... 284 Discussion .............................................................................................................. 292 SUMMARY .......................................................................................................................... 298 LITE•a•JRE CITED ........................................................................................................... 302 AP2ENDIXA (Locality and Other Data for Audiospectrographs) ......................... 313 APPENDIXB (Distribution of Firefinches and Indigobirds) .................................. 322 vi INTRODUCTION Studiesof behaviorhave advancedour understandingof the relationships of birds of the world, both amonggenera and familiesand amongclosely related species.While comparativestudies of the behaviorof closelyrelated birds have generallyconfirmed the ideasof speciesrelationships based on the appearanceof birds, in a few instancesbehavior study has been importantin revealingspecies whose existence was previouslyunsuspected. The eminent pioneerBritish naturalistGilbert White recognizedthe Chiffchaff