University of Nebraska - LincolnDigitalCommons@University of Nebraska - LincolnDucks, Geese, and Swans of the World by Paul A.Johnsgard Papers in the Biological Sciences

2010

Ducks, Geese, and Swans of the World: Contents,Preface, & IntroductionPaul A. JohnsgardUniversity of Nebraska-Lincoln, pajohnsgard@gmail.com

Follow this and additional works at: http://digitalcommons.unl.edu/biosciducksgeeseswans

Part of the Ornithology Commons

This Article is brought to you for free and open access by the Papers in the Biological Sciences at DigitalCommons@University of Nebraska - Lincoln.It has been accepted for inclusion in Ducks, Geese, and Swans of the World by Paul A. Johnsgard by an authorized administrator ofDigitalCommons@University of Nebraska - Lincoln.

Johnsgard, Paul A., "Ducks, Geese, and Swans of the World: Contents, Preface, & Introduction" (2010). Ducks, Geese, and Swans of theWorld by Paul A. Johnsgard. 2.http://digitalcommons.unl.edu/biosciducksgeeseswans/2

DUCKS, GEESE, and SWANS of the World

Paul A. JohnsgardRevised Edition

Ducks, Geese, and Swans of the World

By Paul A. Johnsgard

The only one-volume comprehensive survey of the family Anatidae available in English, this book combines lavish illustration with the most recent information on the natural history, current distribution and status, and identification of all the species.

After an introductory discussion of the ten tribes of Anatidae, separate accounts follow for each of the nearly 150 recognized species. These include scientific and vernacular names (in French, German, and Spanish as well as English), descrip-tions of the distribution of all recognized subspecies, selected weights and mea-surements, and identification criteria for both sexes and various age classes. The “Natural History” section of each species account considers habitats, foods, so-cial behavior, and reproductive biology. Finally, a short discussion of the species’ present population status and current evidence about its evolutionary relation-ships are presented. A glossary of technical terms and derivations of vernacular names and a reference list of more than three hundred sources supplement the text.

A large number of illustrations—more than 170 line drawings and 132 distribu-tion maps—were prepared especially for this volume, which also includes 59 color plates. Each species is illustrated in either line drawing or photograph or both.

One of the world’s foremost authorities on waterfowl behavior, Paul A. Johns-gard is emeritus professor of biological sciences at the University of Nebraska–Lincoln. He is the author of more than 40 books, including Handbook of Waterfowl Behavior, Waterfowl: Their Biology and Natural History, Cranes of the World, Grouse and Quails of North America, North American Game Birds of Upland and Shoreline, Waterfowl of North America, Birds of the Great Plains, Birds of the Rocky Mountains, North American Owls, Trogons and Quetzals of the World, Hawks, Eagles, and Falcons of North America, The Pheasants of the World, The Avian Brood Parasites: Deception at the Nest, The Hummingbirds of North America, Arena Birds: Sexual Selection and Be-havior, and dozens more.

Cover photograph of whooper swans by Paul A. Johnsgard

Ducks, Geese, and Swans of the World

First published and copyright © 1978 by the University of Nebraska Press.

Electronic edition published 2010 by the University of Nebraska–Lincoln Libraries. Copyright 2010 by Paul A. Johnsgard. All rights reserved

Library of Congress Cataloging in Publication Data

Johnsgard, Paul A.Ducks, geese, and swans of the world.

Bibliography: p. 387.Includes index.1. Anatidae. I. Title.

QL696.A52J62 598.4’ 1

Dedicated to The Wildfowl Trust Whose efforts have helped us to understand

and preserve these magnificent birds

Contents

Page Page List of Illustrations xi Hawaiian Goose 74

Preface Canada Goose 76 xv Barnacle Goose 80

Introduction to the Family Anatidae xvii Brant 83

Tribe Anseranatini (Magpie Goose) Red-breasted Goose 86

Magpie Goose 3 Tribe Cereopsini (Cape Barren Goose)

Tribe Dendrocygnini (Whistling or Tree Ducks) Cape Barren Goose 93

Spotted Whistling Duck 7 Tribe Stictonettini (Freckled Duck) Plumed Whistling Duck 8 Freckled Duck 99 Fulvous Whistling Duck 10 Wandering Whistling Duck 12

Tribe Tadornini (Sheldgeese and Shelducks)

Lesser Whistling Duck 15 Blue-winged Goose 103

White-faced Whistling Duck 17 Andean Goose 104

Cuban Whistling Duck 20 Magellan Goose 105

Black-bellied Whistling Duck 21 Kelp Goose 108

White-backed Duck 24 Ashy-headed Sheldgoose 109 Ruddy-headed Sheldgoose 111

Tribe Anserini (Swans and True Geese) Orinoco Goose 113 Mute Swan 29 Egyptian Goose 115 Black Swan 31 Ruddy Shelduck 116 Black-necked Swan 34 Cape Shelduck 118 Trumpeter Swan 36 Australian Shelduck 120 Whooper Swan 39 New Zealand Shelduck 122 Whistling Swan 42 Crested Shelduck 124 Bewick Swan 44 Northern (Common) Shelduck 126 Coscoroba Swan 47 Radjah Shelduck 129 Swan Goose 49 Bean Goose 52 Tribe Tachyerini (Steamer Ducks)

White-fronted Goose 55 Flying Steamer Duck 135

Lesser White-fronted Goose 58 Magellanic Flightless Steamer Duck 136

Graylag Goose 60 Falkland Flightless Steamer Duck 138

Bar-headed Goose 63 Tribe Cairinini (Perching Ducks)

Snow Goose 66 Spur-winged Goose 143 Ross Goose 69 Muscovy Duck 144 Emperor Goose 72 White-winged Wood Duck 146

••• vii

Page Page

Comb Duck 148 Hottentot Teal 245 Hartlaub Duck 151 Garganey 247 Green Pygmy Goose 152 Blue-winged Teal 250 Cotton Pygmy Goose 154 Cinnamon Teal 253 African Pygmy Goose 156 Red Shoveler 256 Ringed Teal 158 Cape Shoveler 257 North American Wood Duck 160 Australasian Shoveler 260 Mandarin Duck 163 Northern Shoveler 262 Australian Wood Duck 165 Pink-eared Duck 265 Brazilian Teal 167 Marbled Teal 268

Tribe Merganettini (Torrent Duck) Tribe Aythyini (Pochards)

Torrent Duck 173 Pink-headed Duck 273 Red-crested Pochard 274

Tribe Anatini Southern Pochard 277 (Dabbling or Surface-feeding Ducks)

Rosybill 279 Blue Duck 179 Salvadori Duck 180

Canvasback 281

African Black Duck 182 Eurasian Pochard 284

Eurasian Wigeon 184 Redhead 287

American Wigeon 187 Ring-necked Duck 290

Chiloe Wigeon 190 Australasian White-eye 292

Falcated Duck 192 Siberian White-eye (Baer Pochard) 295

Gadwall 195 Ferruginous White-eye 297

Baikal Teal 198 Madagascan White-eye 299

Green-winged Teal 200 Tufted Duck 300

Speckled Teal 204 New Zealand Scaup 303

Cape Teal 206 Greater Scaup 305

Madagascan Teal 208 Lesser Scaup 307

Gray Teal 209 Tribe Mergini (Sea Ducks)

Chestnut Teal 211 Eider (Common Eider) 313 Brown Teal 214 King Eider 315 Mallard 216 Spectacled Eider 318 North American Black Duck 219 Steller Eider 321 Meller Duck 222 Labrador Duck 324 Yellow-billed Duck 223 Harlequin Duck 325 Gray Duck 224 Long-tailed Duck (Oldsquaw) 328 Philippine Duck 227 Black Scoter 330 Bronze-winged Duck 228 Surf Scoter 333 Crested Duck 231 White-winged Scoter 335 Pintail 233 Bufflehead 338 Brown Pintail 236 Barrow Goldeneye 340 White-cheeked Pintail 238 Common Goldeneye 343 Red-billed Pintail 241 Hooded Merganser 346 Silver Teal 243 Smew 348

viii •••

Brazilian Merganser Red-breasted Merganser Chinese Merganser Goosander (Common Merganser) Auckland Island Merganser

Tribe Oxyurini (Stiff-tailed Ducks) Black-headed Duck Masked Duck Ruddy Duck

Page

351 352 356 357 361

White-headed Duck Maccoa Duck Argentine Blue-billed Duck Australian Blue-billed Duck Musk Duck

Sources Cited

Glossary and Vernacular Name Derivations

Index

Page

373 376 378 380 382

Illustrations

Figures

Page Page

1. Diagram of Evolutionary Relationships 2. Diagram of External Features and of the Tribes and Genera of Anatidae xviii Feather Areas of Waterfowl 396

Maps

1. Distribution of the Magpie Goose 2 22. Distribution of the Graylag Goose 62 2. Distribution of the Spotted Whistling 23. Distribution of the Bar-headed Goose 65

Duck 6 24. Distribution of the Snow Goose 68 3. Distribution of the Plumed Whistling 25. Distribution of the Ross Goose 71

Duck 9 26. Distribution of the Emperor Goose 73 4. Distribution of the Fulvous Whistling 27. Distribution of the Canada Goose 78

Duck 11 28. Distribution of the Barnacle Goose

Distribution of the Wandering Whistling 82

5. 29. Distribution of the Brant

Duck 14 85

6. Distribution of the Lesser Whistling 30. Distribution of the Red-breasted Goose 88

Duck 16 31. Distribution of the Cape Barren Goose 92

7. Distribution of the White-faced 32. Distribution of the Freckled Duck 98

Whistling Duck 19 33. Distribution of the Blue-winged Goose 103

8. Distribution of the Black-bellied and 34. Distribution of the Andean Goose 105 Cuban Whistling Ducks 23 35. Distribution of the Magellan Goose 107

9. Distribution of the White-backed Duck 25 36. Distribution of the Kelp Goose 109 10. Distribution of the Mute Swan 28 37. Distribution of the Ashy-headed 11. Distribution of the Black Swan 32 Sheldgoose 111

12. Distribution of the Black-necked Swan 34 38. Distribution of the Ruddy-headed

13. Distribution of the Trumpeter Swan 37 Sheldgoose 112

14. Distribution of the Whooper Swan 41 39. Distribution of the Orinoco Goose 114

15. Distribution of the Whistling Duck 43 40. Distribution of the Egyptian Goose 116

16. Distribution of the Bewick Swan 46 41. Distribution of the Ruddy Shelduck 117

17. Distribution of the Coscoroba Swan 49 42. Distribution of the Cape Shelduck 120

18. Distribution of the Swan Goose 51 43. Distribution of the Australian and New

19. Distribution of the Bean Goose 54 Zealand Shelducks 123

20. Distribution of the White-fronted Goose 57 44. Distribution of the Northern Shelduck 128

21. Distribution of the Lesser White-fronted 45. Distribution of the Radjah Shelduck 130 Goose 59 46. Distribution of the Flying Steamer Duck 134

••• xi

Page Page 47. Distribution of the Magellanic and 82. Distribution of the White-cheeked

Falkland Flightless Steamer Ducks 137 Pintail 240 48. Distribution of the Spur-winged Goose 143 83. Distribution of the Red-billed Pintail 242 49. Distribution of the Muscovy Duck 145 84. Distribution of the Silver Teal 245 50. Distribution of the White-winged Wood 85. Distribution of the Hottentot Teal 247

Duck 147 86. Distribution of the Blue-winged Teal and 5l. Distribution of the Comb Duck 150 Garganey 249 52. Distribution of the Hartlaub Duck 152 87. Distribution of the Cinnamon Teal 255 53. Distribution of the Green Pygmy Goose 153 88. Distribution of the Red Shoveler 256 54. Distribution of the Cotton Pygmy Goose 156 89. Distribution of the Cape Shoveler 258 55. Distribution of the African Pygmy 90. Distribution of the Australasian

Goose 157 Shoveler 261 56. Distribution of the Ringed Teal 159 91. Distribution of the Northern Shoveler 264 57. Distribution of the North American 92. Distribution of the Pink-eared Duck 267

Wood Duck 162 93. Distribution of the Marbled Teal 269 58. Distribution of the Mandarin Duck 164 94. Distribution of the Red-crested Pochard 276 59. Distribution of the Australian Wood 95. Distribution of the Southern Pochard 278

Duck 166 96. Distribution of the Rosybill 280 60. Distribution of the Brazilian Teal 168 97. Distribution of the Canvasback 283 6l. Distribution of the Torrent Duck 172 98. Distribution of the Eurasian Pochard 285 62. Distribution of the Salvadori Duck and 99. Distribution of the Redhead 289

Blue Duck 178 100. Distribution of the Ring-necked Duck 291 63. Distribution of the African Black Duck 183 10l. Distribution of the Australasian 64. Distribution of the Eurasian Wigeon 186 White-eye 293 65. Distribution of the American Wigeon 189 102. Distribution of the Siberian White-eye 296 66. Distribution of the Chiloe Wigeon 191 103. Distribution of the Ferruginous 67. Distribution of the Falcated Duck 194 White-eye 298

68. Distribution of the Gadwall 196 104. Distribution of the Tufted Duck 302

69. Distribution of the Baikal Teal 199 105. Distribution of the Greater Scaup,

70. Distribution of the Green-winged Teal 202 New Zealand Scaup, and Madagascan

71. Distribution of the Speckled Teal 205 White-eye 306

72. Distribution of the Cape Teal and 106. Distribution of the Lesser Scaup 309

Madagascan Teal 207 107. Distribution of the Eider 312

73. Distribution of the Gray Teal 210 108. Distribution of the King Eider 317

74. Distribution of the Chestnut Teal and 109. Distribution of the Spectacled Eider 320

Brown Teal 213 110. Distribution of the Steller Eider 323

75. Distribution of the Mallard 218 111. Distribution of the Harlequin Duck 327

76. Distribution of the North American 112. Distribution of the Long-tailed Duck 329 Black Duck 221 113. Distribution of the Black Scoter 332

77. Distribution of the Gray, Philippine, 114. Distribution of the Surf Scoter 335 Yellow-billed, and Meller Ducks 226 115. Distribution of the White-winged Scoter 337

78. Distribution of the Bronze-winged Duck 230 116. Distribution of the Bufflehead 340 79. Distribution of the Crested Duck 232 117. Distribution of the Barrow Goldeneye 342 80. Distribution of the Pintail 235 118. Distribution of the Common Goldeneye 344 81. Distribution of the Brown Pintail 238 119. Distribution of the Hooded Merganser 347

xii ......

Page Page

120. Distribution of the Smew 349 127. Distribution of the Ruddy Duck 371

12l. Distribution of the Brazilian Merganser 352 128. Distribution of the White-headed Duck 375

122. Distribution of the Red-breasted 129. Distribution of the Maccoa Duck 377 Merganser 354 130. Distribution of the Argentine Blue-billed

123. Distribution of the Chinese Merganser 356 Duck 379

124. Distribution of the Goosander 359 13l. Distribution of the Australian Blue-billed

125. Distribution of the Black-headed Duck 366 Duck 381

126. Distribution of the Masked Duck 368 132. Distribution of the Musk Duck 384

Color Plates

following page 96 following page 176 l. White-faced Whistling Duck 29. Comb Duck 2. Magpie Goose 30. Spur-winged Goose

3. Spotted Whistling Duck 3l. Muscovy Duck 4. Plumed Whistling Duck 32. Hartlaub Duck 5. Lesser Whistling Duck 33. African Pygmy Goose 6. Black-bellied Whistling Duck 34. Ringed Teal 7. African White-backed Duck 35. Mandarin Duck 8. Mute Swan 36. Torrent Duck 9. Black Swan 37. American Wigeon

10. Black-necked Swan 38. Chiloe Wigeon 1I. Trumpeter Swan 39. Falcated Duck 12. Whooper Swan 40. Baikal Teal 13. Bewick Swan 4I. Cape Teal 14. Coscoroba Swan 42. Crested Duck 15. Lesser White-fronted Goose 43. Bronze-winged Duck 16. Graylag Goose 44. White-cheeked Pintail 17. Snow Goose 45. Garganey 18. Barnacle Goose 46. Red-crested Pochard 19. Brant 47. Eurasian Pochard 20. Hawaiian Goose 48. Redhead 21. Red-breasted Goose 49. Greater Scaup 22. Cereopsis Goose 50. American Eider 23. Andean Goose 5l. King Eider 24. Magellan Goose 52. Spectacled Eider 25. Ashy-headed Sheldgoose 53. Steller Eider 26. Egyptian Goose 54. Long-tailed Duck 27. Cape Shelduck 55. Harlequin Duck 28. Magellanic Flightless Steamer Duck 56. Bufflehead

57. Barrow Goldeneye

58. Hooded Merganser

59. White-headed Duck

• •• xiii

Of all the books that I have seen and wished that one day I could personally own, perhaps the ones that have most set me to daydreaming are the four-vol­ume set A Natural History of the Ducks, by John C. Phillips. My first contact with this magnificent monograph was at Cornell University, where it could be seen in the rare book collection. I spent countless hours there during the late 1950s savoring the text and plates. At about that same time, the first vol­umes of Jean Delacour's The Waterfowl of the World were appearing, and these too gave me a chance to dream about such entrancing birds as torrent ducks, steamer ducks, musk ducks, and magpie geese. Since then it has been my good fortune to see all of these marvelous birds in life, and they have enriched my own life enormously. The waterfowl family is so rich in ecological diversity, in evolutionary lessons, and in behavioral complexities that I have never tired of either reading or writing about it.

Only two of my previous books, Waterfowl: Their Biology and Natural History and the earlier Hand­book of Waterfowl Behavior, have dealt with the en­tire waterfowl family in a comprehensive fashion, and neither attempted to provide a systematic review of the biology of every species. Indeed, I have re­peatedly thought about undertaking such an effort but each time have shrunk back at the thought of the huge number of species to be considered and of the vast literature that has accumulated on the group. Even in the 1920s it required four volumes for John C. Phillips to review the biology of the waterfowl family exclusive of the swans and geese, and Jean Delacour found that the same number of volumes was needed for his treatment of the entire family.

I decided that, in spite of the concessions that would need to be made, a shorter approach to the family Anatidae was possible, provided that a maxi­mum condensation of text be attained, primarily through avoiding repetitous material such as separate accounts for each subspecies. I also decided to ex­clude taxonomic synonymies, extensive mensural data, and most avicultural information, all of which

Preface

can be found in Delacour's monograph, and likewise to reduce descriptive behavioral information to a minimum whenever it had already been summarized in my Handbook of Waterfowl Behavior. After con­siderable deliberation, it was decided to include plumage descriptions as an aid to identification but not to attempt to describe all molts and plumages. The "Natural History" section of each species ac­count was considered to be the nuclear element, and an effort was made to include newer or at least dif­ferent information from that summarized by Dela­cour. The "Status" and "Relationships" sections were added after the text was well underway, the former because of the increasing incidence of rare and en­dangered forms among the waterfowl, and the latter because more information on phyletic relationships is available now than in 1965, when I last dealt com­prehensively with this problem in the Handbook of Waterfowl Behavior.

Except in a few instances, I have followed the taxo­nomic treatment used in the Handbook, both as to major taxonomic categories and sequences of species within such categories. The two exceptions constitute the recognition of special monotypic tribes for the Cape Barren goose and the torrent duck, since recent studies on both species have cast doubt on their pre­sumed phyletic affinities and thus tribal recognition seemed to provide the best interim solution. The only other major change from the taxonomy used in the Handbook is the transfer of the genus Thalassornis from the stiff tails to the whistling duck tribe. This ac­tion was based on my own studies after the publica­tion of the Handbook and has received independent support from other investigators. A few changes have also been made in species limits and in sub­species recognized, and a moderate number of sug­gested changes in English vernacular names have been adopted. In part these have been to avoid the use of "common" for vernacular names, but also to allow for the consistent formation of distinctive ver­nacular names for each subspecies by simply adding an appropriate adjectival prefix. The group of four

••• xv

swans known as the "northern swans" has proven refractory to such treatment, partly because of their questionable taxonomic status and their still uncer­tain ancestral history. Thus, they have been given separate accounts and treated as if they are "good" species, in spite of the obvious fact that they are not. There are thus 148 separate species accounts in the text.

The writing of the text was begun in the spring of 1976 and continued through most of 1977, so that later literature was included only if it was regarded as of critical importance. Further, the number of litera­ture citations was held to an absolute minimum, but one or more "Suggested Readings" for each species was included to provide additional access to the near­ly endless literature on the waterfowl family. I would like to express my sincere appreciation to the School of Life Sciences for supporting this work and for al­lowing me the time needed to complete it.

In addition, I must again thank a number of in­dividuals for their invaluable aid. These include vir­tually all of the staff of the Wildfowl Trust, but especially Sir Peter Scott, Dr. Geoffrey Matthews, and Dr. Janet Kear. I would also like to thank Jean

xvi ......

Delacour for encouraging me to undertake the book in spite of its potential competition with his own monograph. Not only have I relied extensively on the volumes by Delacour and Phillips but also on the regional volumes by H. J. Frith (Australia), G. Dementiev and N. Gladkov (U.S.S.R.), P. A. Clan­cey (South Africa), S. Ali and D. Ripley (India), and C. Tso-hsin (China) for various mensural and descriptive information, sometimes without citations to these sources. I also wish to thank David Skead for providing unpublished data on South African species.

The distribution maps have been based on a va­riety of sources, including the volumes just men­tioned. The photographs are mostly of captive birds, taken at the Wildfowl Trust. All the photographs and line drawings are my own, although several of the drawings are based on published photographs taken by a variety of other photographers. In cases of rare or extinct species I have sometimes used photographs of live birds representing close relatives for propor­tions and postures, but virtually none of the draw­ings lack a documentary base.

Introduction to the Family Anatidae

Inasmuch as the primary purpose of this book is to provide information on each of the species of the waterfowl family in a standardized format and easily accessible manner, it is important that the reader have some knowledge of the basis for my sequential organization of these species. A variety of attempts to provide a "natural" classification, or one that best reflects actual evolutionary relationships, of the family Anatidae have been made in recent years, with most of them being minor variations on a scheme first proposed by Jean Delacour and Ernst Mayr in 1945. In this landmark classification, em­phasis was given to the association of species at the tribal level, rather than to the fragmentation of the family into a large number of subfamilies, as in earlier classifications.

My own behavioral studies of the family resulted in a proposed classification for the group in 1961, which was utilized in my subsequent books (1965a, 1968a) and has been subject to only minor modifica­tion since that time based on new information from my own and other studies. In brief, the family Anatidae is here regarded to be composed of 3 sub­families, 13 tribes, 43 genera, and 148 recent species as follows:

Family Anatidae (ducks, geese, and swans) Subfamily Anseranatinae

Tribe Anseranatini: Magpie goose (1 genus and species)

Subfamily Anserinae Tribe Dendrocygnini: Whistling or tree ducks (2 genera, 9 species) Tribe Anserini: Swans and true geese (4 genera, 21 species) Tribe Cereopsini: Cape Barren goose (1 genus and species) Tribe Stictonettini: Freckled duck (1 genus and species)

Subfamily Anatinae Tribe Tadornini: Sheldgeese and Shelducks (5 genera, 15 species)

Tribe Tachyerini: Steamer ducks (1 genus, 3 species) Tribe Cairinini: Perching ducks (9 genera, 13 species) Tribe Merganettini: Torrent duck (1 genus and species) Tribe Anatini: Dabbling or surface-feeding ducks (4 genera, 39 species) Tribe Aythyini: Pochards (3 genera, 16 species) Tribe Mergini: Sea ducks (8 genera, 20 species) Tribe Oxyurini: Stiff-tailed ducks (3 genera, 8 species)

These groups are believed to be related to one another in the manner shown in figure 1, which in­dicates the probable relationships of the 13 tribes and 43 genera recognized in this book. Similar diagrams showing species relationships for each of the major tribes have been published earlier Oohnsgard, 1961a), and with relatively few more recent modifi­cations still provide the basis for the sequence in which individual species are considered in this book. Behavioral and anatomical characteristics that pro­vide the basis for the association of these species into tribes and subfamilies are those which are regarded as particularly significant, and thus it is worth review­ing such "emergent" characteristics before the spe­cies-by-species consideration of the entire family.

SUBFAMILY ANSERANATINAE

Tribe Anseranatini (Magpie Goose)

This subfamily is composed of a single or mono typic tribe, genus, and species, the magpie goose, which differs so much from the remainder of the family that some persons have argued that it might best be plac­ed in a separate family. However, it also provides such important transitional characteristics between the more typical waterfowl and the South American screamers of the family Anhimidae that it is perhaps most useful to retain it in the Anatidae as a "land-

...... xvii

Pl£CTJWTmJS CAIRI/l<\ PTOO£TTA ~IDI~IS ~Pru) CAl.lJJ£TTA AIX Gflft£JTA I\Wcr£TTA

SlflIXlESE ;1NO SHELIDJ<S CTJlJXJRN IN D

BRJWfA

(

crn:CPSIS , "-

f'[J{MTIA

I I

IiT71IDAIMJS ~ ~ ~A AYTlNA

\ I , , \ I \ I I I , / I I

I /. SU~ACE-FEEDI~ IU:K) VWllTIND

OXYlJPA BlZIUPA

I1ff PAm (:m3E (crn:CPSIND

STICTcr£TTA ..... ,

\

\ STIFF-TAIlED IU:K) (QX't1JRIND

\ FIHKl.ED rm< (STICTcr£TTIND \

\

~~IS

mJPIE (:m3E ~TIND

mark" form, against which the other species can use­fully be measured.

Foremost among the magpie goose's peculiarities are its feet, which are only slightly webbed, and its unusually long hind toes, which are associated with

xviii +++

~-LIKE ftUSTCR

the species' semiterrestrial adaptations and its perch­ing behavior. Like the other Anatidae, the magpie goose molts its major flight feathers (primaries and secondaries) only once a year; but unlike virtually all of these other species, the magpie goose molts very

gradually, with only a few feathers being absent at anyone time, and thus the birds are continuously able to fly. There is no flightless period of increased vulnerability to predation, and the greatly prolonged period of molting is not a major disadvantage to this tropically adapted and nearly sedentary species.

A second unique anatomical feature of this species is the greatly elongated trachea in adults of both sexes, which in adult males may reach 150 centi­meters. The magpie goose is unlike some swans in which the trachea is convoluted inside the sternum. Rather, in this species it penetrates the area between the breast muscles and the skin, in a manner com­parable to that in certain species of Cracidae Oohns­gard, 1961b). As in the latter species, the resulting call is unusually low-pitched, and the elongated trachea probably functions as an effective resonator of low-frequency sounds. Other than this specializa­tion, however, the anatomy of the sound-producing syrinx is relatively simple and gooselike.

A third remarkable feature of the magpie goose is related to its breeding behavior. The birds often forrr, a trio consisting of a male and two females that drop their eggs in a single nest, with all three birds sharing the incubation responsibilities. This behavior, first observed in captive birds Oohnsgard, 1961c), was subsequently found to be typical also of wild in­dividuals, and appears to be unique in the family. In addition, magpie geese are the only waterfowl that feed their young directly, the adults pickip..g up edible materials in their bills and dropping them in front of their downy young. This behavior has its counter­part in the "tidbitting" behavior of many gal­linaceous birds, but has not yet been reported from other Anatidae.

SUBFAMILY ANSERINAE

The subfamily Anserinae includes the whistling duck, swans, true geese, and two "aberrant" species. Like the magpie goose, these species undergo only a single molt per year, which occurs after the breeding season and during which all feathers are replaced. However, the flight feathers are shed almost simul­taneously, so that the birds are unable to fly for a period of from about three to six weeks. In all of the included species the unfeathered part of the lower leg, or tarsus-like that of the magpie goose-has an irregular network, or reticulated pattern, of scales throughout. Except in two semi terrestrial geese, how­ever, the front toes are fully webbed. In all species

the sexes are essentially identical in plumage but often differ somewhat in body weight and, occa­sionally, in voice. Although the whistling ducks have relatively long hind toes, not even they perch as well as does the magpie goose, and the other species do not perch at all. All of the species lack iridescent coloration, even on the wings.

Tribe Dendrocygnini (Whistling Ducks)

The whistling ducks are a group of nine species, eight of which are readily placed in the single genus Den­drocygna, or "tree ducks." However, they are not primarily perching birds, and thus "whistling ducks" is a better vernacular designation than the frequently used "tree ducks." In nearly all species both sexes ut­ter a clear, often multisyllabic whistle that readily identifies the bird as to its species and apparently provides important communication signals in these rather gregarious birds. Most of the species are tropi­cal in distribution, and in all of them the pair bond seems to be permanent and potentially lifelong. Both sexes share equally in brood-rearing responsibilities, and in some species the male is known to participate in incubation as well. Unlike those of geese and swans, the downy young are distinctively patterned. Although the downy young of the white-backed duck differ somewhat from those of Dendrocygna, the species shares a sufficiently large number of behavioral and anatomical traits to be tentatively included in this tribe.

Tribe Anserini (Swans and True Geese)

The swans and true geese are moderately to extreme­ly large waterfowl, which in common with the whis­tling ducks have plumage patterns that are alike in both sexes and lack iridescent coloration, and they also possess reticulated scale patterns on the tarsal surfaces. Most of the 20 species are found in the cooler parts of the Northern Hemisphere, the excep­tions being 3 species of Southern Hemisphere swans. All are vegetarians, obtaining much of their food from terrestrial surface vegetation in the case of geese, and from subsurface aquatic vegetation in the case of swans. The patterns of the downy young tend to be pale and simple, without strong head or back patterning, and in most species the adult plumages are also fairly simple, with whites and blacks often predominating. The white plumage of most adult swans appears to be related to visibility needs associ­ated with their high degree of territorial spacing. The

......... xix

most highly territorial swans are also the most strongly vocal ones, for the same reason. However, vocalizations of the sexes are very similar, and usu­ally differ only in minor pitch characteristics. Most of the swans and geese are quite strongly migratory, but the insular Hawaiian goose not only has become nonmigratory but also has become semiterrestrial and has evolved reduced toe webbing as it has adapted to a mountainous existence on old lava fields.

Tribe Cereopsini (Cape Barren Goose)

Several recent studies have suggested that this un­usual Australian gooselike bird is not very closely related to either the true geese or the sheldgeese, although it shares some traits with both groups. It has some unique traits, such as its unusually swollen bill, its adaptations to a terrestrial existence on the coastline and islands of the Bass Strait, and its very simple syringeal structure. Like the freckled duck, it is perhaps best considered as a survivor of a group transitional between the two major subfamilies of waterfowl that exist at the present time.

Tribe Stictonettini (Freckled Duck)

Even more than the Cape Barren goose, the freckled duck exhibits an assortment of anatomical traits that suggest affinities with the geese and swans, in spite of a fairly typical ducklike appearance and foraging behavior. Its unpatterned downy young, its remark­ably primitive syringeal structure, and its reticulated tarsus all strongly argue for the position that this species is the sole survivor of a very ancient water­fowl lineage, with no near living relatives. A detailed study of its social behavior is greatly to be desired, for like the magpie goose, it provides an unequaled opportunity to gain insight into the evolutionary his­tory of the waterfowl group through observation of a unique contemporary form.

SUBFAMILY ANATINAE

The third and largest subfamily, Anatinae, includes the sheldgeese, shelducks, and all of the typical ducks. It is subdivided into a varying number of tribes by different authorities; nine are recognized here. In most if not all of the species included in this subfamily there are two molts of the body feathers per year, and consequently there are usually two

xx +++

distinct plumages, breeding (nuptial) and non­breeding (winter, or eclipse). In some species the breeding plumage of the male closely resembles that of the females, but more often the sexes have quite different breeding plumages, in conjunction with more frequently disrupted and renewed pair bonds. Likewise, the adult voices of the two sexes are nor­mally very different in these species as the result of sexual differences in the structure of the syrinx and sometimes also the trachea. Unlike that in the pre­vious subfamilies, the front surface of the lower tar­sus has a linearly arranged (scutellated) scale pattern. Iridescent coloration is frequently present in the plumage, particularly among males, although on fe­males it is usually restricted to the region of the secondaries of the wings. Such colorful patterns are called speculums and are usually species-specific.

In those species in which the sexes are quite dif­ferent, or dimorphic, in size and appearance, the male is typically larger, more brilliantly patterned, and more aggressive. The plumages of juveniles and the nonbreeding plumages of males generally re­semble that of the adult female, and lack both irides­cent coloration on the body and the finely barred, or vermiculated, markings on the back, sides, and flanks that are typical of many of the species of this subfamily. The patterns of the downy young are often quite contrasting and distinctive, and usually include spotting and striping on the head and back. In no cases are males known to assist in incubation, but male participation in brood rearing is often variable within and between tribes, and is related primarily to such ecological factors as length and regularity of the breeding seasons.

Tribe Tadornini (Sheldgeese and Shelducks)

The most gooselike species of the subfamily Anatinae are the sheldgeese, which together with the closely related shelducks constitute the tribe Tadornini. This group of 14 species has a worldwide distribution ex­cept for North America. The typical sheldgeese are grazing birds, the ecological counterparts of the true geese, while the shelducks are mostly wading and dabbling birds, frequently feeding to a large extent on aquatic invertebrates. In all of the species the adult male has an enlarged bony bulla in the syrinx, which is evidently responsible for the whistling or whistlelike sounds that are important in sexual and aggressive displays. The females of all species have more reedy and typically gooselike or ducklike notes. In all species the males are larger than the females,

and often differ appreciably from them in plumage. Although pair bonds are sometimes said to be perma­nent in the group, in some species at least they may be ruptured through interactions with outside males, and a premium is placed on male aggressiveness dur­ing sexual competition for mates. The wings are used in fighting and in most species they are strongly pat­terned, with white coverts and iridescent coloration on the secondaries or their greater coverts. The downy young are also typically patterned contrast­ingly in the shelducks and sheldgeese, a characteristic shared with various other cavity-nesting waterfowl.

Tribe Tachyerini (Steamer Ducks)

The South American steamer ducks have at times been included with the shelducks, but differ enough from them in structure and behavior to be regarded as a separate but closely related tribe. There are three species very similar in appearance; two are essentially flightless. All are found off the coasts of southern South America and the Falkland Islands, where they feed on mollusks and other marine in­vertebrates. The males differ slightly from females in their plumage and vocalizations, but in both sexes iridescent coloration is totally lacking and on­ly a simple white speculum is present on the wings. Like the shelducks, however, they are highly ag­gressive during social display activities. The downy young to some extent resemble those of shelducks, but have less spotting and less contrasting colora­tion.

Tribe Caidnini (Perching Ducks)

This group of 13 species of primarily perching waterfowl is a rather heterogeneous assemblage of birds that are not easily characterized. In addition to being generally perching and cavity-nesting, they also have fairly wide, rounded wings, elongated tails, and sometimes also relatively long legs. Many of the species exhibit a great deal of iridescent col­oration in their plumage, even among females, and in a few species nearly the entire body plumage is iridescent. In some of these brilliantly colored forms, such as the comb duck, muscovy duck, and the spur-winged goose, there is a great difference in the sizes of the sexes even though they may be very similar in plumage patterning. In spite of their brilliant plumages, males of only a few of the species exhibit definite eclipse plumages, probably in part because most of the forms are tropical, with

long or irregular breeding seasons. Pair bonding is generally seasonally established in the species that breed in temperate climates, while in the more tropical and seemingly more primitive species the pair bonds are weak and in a few cases apparently even nonexistent. The patterns of the downy young are typically well marked and characterized by white or yellow spots and stripes on a darker background; in many species they are not readily separable from the downy young of dabbling ducks. The two tribes are obviously closely related, and taxonomists are not agreed on which group some species such as the ringed teal, pink-eared duck, and Brazilian teal should be included in. However, to merge the tribes would make a com­paratively large tribe and tend to obscure the well­defined differences in the behavior patterns and breeding biologies of these two groups.

Tribe Merganettini (Torrent Duck)

This remarkable stream-dwelling duck of the An­dean mountains is certainly one of the most specialized of all waterfowl, and in part its anatomical and behavioral specializations have obscured its basic relationships, which appear to be with either the perching ducks or the dabbling ducks. In the absence of definitive evidence, it seems reasonable to maintain a separate tribe for this species, which exists as a series of relatively isolated populations between Venezuela and Tierra del Fuego that vary greatly in male plumage char­acteristics. Torrent ducks are essentially cavity- or ledge-nesting forms, although only a few nests have been found, and much still remains to be learned of their breeding biology.

Tribe Anatini (Dabbling Ducks)

The dabbling, or surface-feeding, ducks are, to judge from the number and abundance of the in­cluded species, the most successful of all waterfowl. This tribe includes all of the "puddle ducks" that constitute most of the important game species throughout the world. Of the 39 species making up the tribe, all but 3 can readily be placed in the single genus Anas. The tribe has a worldwide distribution, with some of the species occurring on several continents and having extensive transcon­tinental migration patterns. However, most of the species are temperate-breeding forms and are generally adapted to shallow, marshy habitats

••• xxi

where food can be obtained from near the surface by dabbling or tipping-up. In most species the males have fairly elaborate and colorful breeding plumages, whereas the ground-nesting females are mostly cryptically patterned with buff and brown. In nearly all species both sexes have iridescent wing speculum markings, and in all species the trachea has an enlarged bulla at the syrinx. Pair bonds are generally reformed each year during the non­breeding season, but in some species with long breeding seasons the pair bonds are relatively per­manent and the males remain with their offspring and help to protect them.

Tribe Aythyini (Pochards)

This tribe of primarily fresh-water diving ducks contains 16 species that collectively may be called pochards. The tribe has a nearly worldwide distri­bution, but only a few of its species have ranges that extend beyond a single continent. In addition to 15 species that are very similar in body propor­tions and diving adaptations, the apparently ex­tinct pink-headed duck has anatomical character­istics that approach those of the pochards and it clearly should be included in this tribe. All of the typical pochards are adept at diving and possess large feet, with long outer toes and strongly lobed hind toes. Their legs are placed quite far apart and are situated farther back on the body than in other ducks, making the birds relatively awkward on land but improving their diving efficiency. They also have a heavier body size to wing-surface ratio, forcing them to run for some distance over the water when taking flight, in contrast to the "spring­ing" takeoff of dabbling ducks. Although sexual dimorphism occurs to some extent in all species, male plumage patterns are generally not especially complex, and the wing speculum patterns are either lacking or limited to gray or white stripes. The females of pochards are usually rather uniformly brownish, and lack the very distinct patterning of female dabbling ducks. Nesting is usually done on land near water or, more commonly, in beds of emergent vegetation. The downy young tend to be weakly or obscurely patterned with shades of yellow and dark brown.

Tribe Mergini (Sea Ducks)

The sea duck tribe, which here includes the eiders, consists of 20 species that are all superb diving

xxii •••

birds. They are found in fresh-water as well as marine habitats, and primarily have Northern Hemisphere distribution patterns. Except for the two isolated Southern Hemisphere species, all of the sea ducks have considerable sexual dimorphism in plumage. Males in breeding plumage are usually elaborately patterned, often with predominantly black and white markings, which probably serve very well to localize and identify these birds at considerable distances in their marine environ­ments. However, iridescent coloration is generally limited to the head, and the wing speculum pat­terns, instead of being iridescent, are generally white and black. Nesting is usually done on fairly open shoreline or in grassy tundra, as in the eiders and long-tailed duck, or in cavities, under heavy brush, or in similar well-concealed locations, as in the goldeneyes, mergansers, and harlequin duck. Females of the ground-nesting forms approach the patterns found among female dabbling ducks in their cryptic coloration, and the downy young of these species are also rather brownish and obscure­ly patterned. Females of the hole-nesting species are more uniformly brownish and their ducklings are frequently contrastingly spotted with white and dark markings.

Tribe Oxyurini (Stiff-tailed Ducks)

The stiff-tailed ducks are characterized by several unusual features in addition to their long, stiffened tail feathers that serve as underwater rudders. Among other adaptations are their very large feet, which are placed so far back on the body that it is difficult for these birds to walk on land. The body feathers are small, numerous, and have a grebelike sheen, and the wings are so short that takeoff and flight is attained with difficulty. All of the species have relatively short and thick necks, which in males can be enlarged by the inflation of various internal structures during sexual display. Although all of the species exhibit some dimorphism of size or coloration, the plumage patterns are mostly shades of gray, ruddy brown, and black, with con­trasting white markings largely limited to the head. Only one species, the masked duck, exhibits a dis­tinct speculum, and this species is furthermore the only one that is able to attain flight easily. The downy plumage patterns are usually very similar to those of the adult females, which tend to be incon­spicuously patterned with grays and browns. Non­breeding plumages of males also closely resemble

those of the females, and during this period the ruddy coloration of the typical forms is largely lost, as is the unusual blue color of the male's bill. Two species that do not fit this general pattern are the Australian musk duck and the South American black-headed duck. The musk duck may readily be considered a typical stiff tail that, under evolu­tionary pressures associated with a highly com­petitive mating system favoring strength and aggressiveness, has become remarkably large and has evolved bizarre male displays. However, the black-headed duck lacks many of the traits of the stiff-tailed ducks, and in many anatomical features

more closely approaches the dabbling ducks. In ad­dition to providing an apparent evolutionary link with that group, the black-headed duck is also the only species of Anatidae that seems to have be­come a total social parasite, abandoning its nest­building tendencies in favor of dropping its eggs in the nests of a variety of host species. In this sense it is one of the most specialized of all waterfowl species, although its parasitic adaptations are relatively primitive by comparison with those of some of the better-known species of social para­sites.

+++ xxiii