SPECIES RELATIONSHIPS IN THE AVIAN GENUS dIAdOPI-llLd BY LARRY L. WOLF Museumof VertebrateZoology Universityof California ORNITHOLOGICAL MONOGRAPHS NO. 23 PUBLISHED BY THE AMERICAN ORNITHOLOGISTS' UNION 1977 SPECIES RELATIONSHIPS IN THE AVIAN GENUS •IZA4tOPZ--ZZL•I ORNITHOLOGICAL MONOGRAPHS This series,published by the American Ornithologists'Union, has been establishedfor major papers too 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 seriesshould be addressedto the Editor, Dr. John William Hardy, Departmentof Natural Science,The Florida StateMuseum, University of Florida, Gainesville,Florida 32611. Copiesof OrnithologicalMonographs may be orderedfrom the Assistant to the Treasurerof the AOU, Glen E. Woolfender•Department of Biology, Universityof SouthFlorida, Tampa, Florida 33620. (See price list on back and inside back cover.) OrnithologicalMonographs No. 23, viii + 220 pp. Editor of A.O.U. Monographs,John William Hardy SpecialAssociate Editors of this issue,John P. Hubbard, Dela- ware Museum of Natural History, Greenville,Delaware 19807, and Ralph J. Raitt, Departmentof Biology,New Mexico State University,Las Cruces,New Mexico 88001 AssistantEditor, June B. Gabaldon Author, Larry L. Wolf, Departmentof Biology, SyracuseUni- versity, Syracuse,New York 13210 First received, 24 January 1974; accepted,2 February 1976; final revisioncompleted, 9 January 1976 Issued February 23, 1977 Price (includeslong-play phono-discalbum) $12.00 prepaid ($10.50 to AOU Members) Library of CongressCatalogue Card Number 77-73658 Primedby the Allen Press,Inc., Lawrence,Kansas 66044 Copyright ¸ by American Ornithologists'Union, 1977 ii SPECIES RELATIONSHIPS IN THE AVIAN GENUS •1IMOPHIL•I BY LARRY L. WOLF Museum of Vertebrate Zoology Universityof California ORNITHOLOGICAL MONOGRAPHS NO. 23 PUBLISHED BY THE AMERICAN ORNITHOLOGISTS' UNION 1977 TABLE OF CONTENTS INTRODUCTION .................................................................................. 1 ACKNOWLEDGMENTS ......................................................................... 2 METHODS AND MATERIALS ............................................................ 3 lqELI• WOR•C .................................................................................... 3 MEASUREMENTS .............................................................................. 4 NOMENCLATURAL BACKGROUND ................................................ 5 DISTRIBUTION .................................................................................... 7 SPECIES ACCOUNTS .......................................................................... DISCUSSION ................................................................................ 32 PLUMAGES AND MOLTS ................................................................... 37 PLUtOAGES ...................................................................................... 37 SPECIES ACCOUNTS .................................................................. 37 DISCUSSION ............................................................................. 44 MOLT ....................................................................................... 52 POST JUVENAL MOLT ............................................................. 52 PRENUPTIAL MOLT .............................................................. 60 POSTNUPTIAL MOLT ................................................................ 67 DISCUSSION ................................................................................ 73 GENERAL BIOLOGY .......................................................................... 80 VOCALIZATIONS ................................................................................. 95 SPECIES ACCOUNTS ......................................................................... 95 DISCUSSION ..................................................................................... 123 BREEDING SEASONS ......................................................................... 127 SPECIES ACCOUNTS ............................................................................ 127 DISCUSSION ................................................................................... 133 NEST STRUCTURE ............................................................................ 134 SPECIES ACCOUNTS .......................................................................... 135 Discussion .................................................................................... 140 v EGG COLOR ......................................................................................... 141 EXTERNAL MORPHOLOGY .............................................................. 146 WING LENGTH .................................................................................. 147 TAIL LENGTH .................................................................................... 155 TARSUS LENGTH ................................................................................ 157 TOE LENGTH .................................................................................... 160 BILL PROPORTIONS .......................................................................... 160 DISCUSSION OF APPENDAGES ............................................................ 162 ANALYSIS OF VARIATION .................................................................. 165 INTERNAL MORPHOLOGY .............................................................. 168 APPENDICULAR SKELETON .............................................................. 170 SQUAMOSALREGION ........................................................................ 181 TRANSPALATINE PROCESS ................................................................ 184 MUSCLE SCAR IN TEMPORAL FOSSA ................................................ 185 SKULL OSSIFICATION ........................................................................ 187 DISCUSSION .......................................................................................... 192 CLASSIFICATION AND EVOLUTION .............................................. 199 GENERIC CLASSIFICATION .............................................................. 203 SUMMARY ............................................................................................ 207 LITERATURE CITED .......................................................................... 209 PLATES (1-10) ................ 36, 38, 97, 99, 103, 105, 110, 112, 117, 122 LONG-PLAY PHONO DISC ALBUM ................................................ Suppl. vi LIST OF FIGURES Figure 1. Geographic distribution of A. ruficauda and A. quinquestriata ............ 8 2. Geographic distribution of A. sumichrasti,A. humeralis, A. mystacalis, and A. carpalis .............................................................................................. 12 3. Geographicdistribution of A. ruficeps ........................................................ 15 4. Geographic distribution of A. rufescens and A. notosticta .................... 20 5. Geographic distribution of the botterii complex ...................................... 23 6. Molt cycles in four speciesof Aimophila .................................................. 74 7. Breeding seasonsof 12 speciesof Aimophila ........................................... 133 8. Relationship between mean body weight and equated wing length for 12 speciesof Aimophila ............................................................................. 152 9. Relationship between mean body weight and equated tail length for 12 species of Aimophila ................................................................................. 154 10. Relationshipbetween mean body weight and equated tarsal length for 12 speciesof Aimophila .............................................................................. 158 11. Relationship between equated wing length and equated tarsal length for 12 species of Aimophila ...................................................................... 163 12. Relationships between carpus, wing length, and body weight ................ 169 13. Relationshipsbetween tarsus, leg length, and body weight .................... 171 14. Two types of squamosal region .............................................................. 182 15. Three shape categories of posterior border of transpalatine .................. 184 16. Development of fully ossified skull .......................................................... 188 17. Hypothetical phylogeny for 11 speciesof Aimophila .............................. 200 LIST OF TABLES Table 1. Occurrence of Some Juvenal and First Winter Plumage Characteristics among the Species of Aimophila .................................................................. 44 2. Occurrence of Certain Adult Plumage Characteristics among the Species of Aimophila .................................................................................................. 45 3. Postjuvenal Body Molt of A. cassinii ......................................................... 53 4. Numerical Scoring for Prenuptial Molt in Aimophila ................................ 60 5. Average Numerical Values of Prenuptial Molt ......................................... 61 6. Percent Distribution of Individuals of Haemophila Group in Categories of Prenuptial Molt ....................................................................................... 62 7. Stages of Postnuptial