Table Of ContentThe North American
Whistling-Ducks, Pochards,
and Stifftails
Paul A. Johnsgard
Although the 12 species representing three waterfowl tribes described in this volume are not closely
related, they fortuitously provide an instructive example of adaptive evolutionary radiation within the
much larger waterfowl lineage (the family Anatidae), especially as to their divergent morphologies, life
histories, and social behaviors.
The whistling-ducks (Dendrocygna), with three known North American species, are notable for their
permanent pair-bonds, extended biparental family care, and strong social cohesion. In contrast, males
of the five typical pochards of North American diving ducks (Aythya) establish monogamous pair-bonds
that are maintained only long enough to assure that the female’s eggs are fertilized. The endpoint of this
behavioral gradient, promiscuity or polygyny, exists among at least some of the typical stifftails (Oxyura).
Such diverse reproductive strategies have exerted powerful evolutionary influences on interspecies
variations in sexual dimorphism, sexual behavior, anatomy, ecology, and other traits.
This volume includes more than 63,000 words, plus some 200 maps, photos, drawings, and sketches,
and nearly 650 literature citations. It is the last of five volumes that describe all 55 waterfowl species
that have been historically documented in North America; collectively, the volumes total over 300,000
words, with nearly 3,000 literature citations, and more than 600 maps, photos, drawings, and sketches.
ISBN: 978-1-60962-110-0
doi: 10.13014/K28913SK
Zea Books
Lincoln, Nebraska
- , ,
the north american whistling ducks pochards
and stifftails
The North American
Whistling-Ducks,
Pochards, and
Stifftails
Paul A. Johnsgard
School of Biological Sciences
University of Nebraska–Lincoln
Zea Books, Lincoln, Nebraska 2017
My five volumes (Johnsgard, 2016–17) on North American waterfowl
are dedicated to the memory of Hans Albert (“Al”) Hochbaum (1911–1988),
who proved that waterfowl monographs can be written by one with the eyes of a naturalist,
the pen of an artist, and the heart of a poet.
Text, photos, and illustrations copyright © 2017 Paul A. Johnsgard
ISBN: 978-1-60962-110-0
https://doi.org/10.13014/K28913SK
Composed in Adobe Garamond and Imprint MT Shadow types.
Spot illustrations: p. 1, Lesser scaup, male; p. 2, Redhead, pair; p. 6, Ring-necked duck, pair;
p. 20, Black-bellied whistling-duck, pair; p. 22, Black-bellied whistling-duck, adult;
p. 52, Canvasback, pair; p. 115, Greater scaup, male;
p. 129, Ruddy duck, male-tail-cocking in front of female;
p. 183, Ruddy duck, courting group
Zea Books are published by the University of Nebraska–Lincoln Libraries
Electronic (pdf) edition available online at http://digitalcommons.unl.edu/zeabook/
Print edition available from http://www.lulu.com/spotlight/unllib
UNL does not discriminate based upon any protected status.
Please go to unl.edu/nondiscrimination
Abstract
Although the 12 species representing three waterfowl tribes described in this volume are not
closely related, they fortuitously provide an instructive example of adaptive evolutionary radia-
tion within the much larger waterfowl lineage (the family Anatidae), especially as to their diver-
gent morphologies, life histories, and social behaviors.
The whistling-ducks (Dendrocygna), with three known North American species, are notable
for their permanent pair-bonds, extended biparental family care, and strong social cohesion. In
contrast, males of the five typical pochards of North American diving ducks (Aythya) establish
monogamous pair-bonds that are maintained only long enough to assure that the female’s eggs
are fertilized. The endpoint of this behavioral gradient, promiscuity or polygyny, exists among
at least some of the typical stifftails (Oxyura). Such diverse reproductive strategies have exerted
powerful evolutionary influences on interspecies variations in sexual dimorphism, sexual behav-
ior, anatomy, ecology, and other traits.
For example, the locomotory anatomies and swimming abilities of the three groups vary
greatly. The whistling-ducks are all long-legged species that are well adapted to both walking and
swimming but are poor at diving. All five North American pochards swim and dive superbly but
walk awkwardly on land. They usually nest above water in emergent vegetation or very close to
water. The two North American stiff-tailed ducks are among the most accomplished swimmers
and divers of all waterfowl. They construct easily accessible, semifloating reed nests among emer-
gent vegetation, but their hind-set legs and large feet have become so specialized for aquatic lo-
comotion that they can barely walk on land.
The flying abilities of the three groups also diverge greatly. The pochards are all remarkably
swift fliers: the canvasback has been clocked in excess of 70 mph, and radio-tagged lesser scaups
have flown more than 2,000 miles from North Dakota to Cuba in as few as three days. In con-
trast, the whistling-ducks are among the slowest flyers of all North American ducks. Their tropi-
cal populations are mostly nonmigratory, although fulvous whistling-ducks have been known to
cross the 90-mile ocean gap between Florida and Cuba. Lastly, stiff-tailed ducks have such small
wing areas and correspondingly high wing-loading that they typically dive, rather than fly, to es-
cape danger. Ruddy ducks can take flight only after a running start, reaching air speeds of only
about 45 miles per hour. Their seasonal migrations are relatively prolonged, so they are among
the last waterfowl to arrive on their northernmost breeding areas. Such long migrations are prob-
ably undertaken by spreading them out over many shorter segments.
This volume includes more than 63,000 words, plus some 200 maps, photos, drawings, and
sketches, and nearly 650 literature citations. It is the last of five volumes that describe all 55 wa-
terfowl species that have been historically documented in North America; collectively, the vol-
umes total over 300,000 words, with nearly 3,000 literature citations, and more than 600 maps,
photos, drawings, and sketches.
5
Contents
List of Distribution Maps . . . . . . . . . . . . . . . . . . . . . 9
List of Figures. . . . . . . . . . . . . . . . . . . . . . . . . 9
List of Photographs . . . . . . . . . . . . . . . . . . . . . . . 10
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
I. Introduction . . . . . . . . . . . . . . . . . . . . 13
II. Species Accounts . . . . . . . . . . . . . . . . . . . 20
Tribe Dendrocygnini (Whistling-Ducks) . . . . . . . . . . . . . . . 21
Fulvous Whistling-Duck . . . . . . . . . . . . . . . . . . . 23
West Indian Whistling-Duck. . . . . . . . . . . . . . . . . . 35
Black-bellied Whistling-Duck . . . . . . . . . . . . . . . . . 38
Tribe Aythyini (Pochards) . . . . . . . . . . . . . . . . . . . . 50
Canvasback . . . . . . . . . . . . . . . . . . . . . . . 53
Eurasian (Common) Pochard . . . . . . . . . . . . . . . . . 67
Redhead . . . . . . . . . . . . . . . . . . . . . . . . 71
Ring-necked Duck. . . . . . . . . . . . . . . . . . . . . 85
Tufted Duck. . . . . . . . . . . . . . . . . . . . . . . 98
Greater Scaup . . . . . . . . . . . . . . . . . . . . . . 103
Lesser Scaup. . . . . . . . . . . . . . . . . . . . . . . 116
Tribe Oxyurini (Stiff-tailed Ducks) . . . . . . . . . . . . . . . . . 128
Masked Duck . . . . . . . . . . . . . . . . . . . . . . 130
Ruddy Duck . . . . . . . . . . . . . . . . . . . . . . 141
III. References . . . . . . . . . . . . . . . . . . . .159
The Birds of North America Monographs . . . . . . . . . . . . . . 159
Taxonomic Works and General Studies . . . . . . . . . . . . . . 159
National, Regional, and Local Surveys . . . . . . . . . . . . . . .162
7
8 Contents
Whistling-Ducks: Multiple Taxa. . . . . . . . . . . . . . . . . 166
Fulvous Whistling-Duck. . . . . . . . . . . . . . . . . . 166
West Indian Whistling-Duck . . . . . . . . . . . . . . . . 167
Black-bellied Whistling-Duck . . . . . . . . . . . . . . . . 168
Pochards: Multiple Taxa . . . . . . . . . . . . . . . . . . . 169
Canvasback. . . . . . . . . . . . . . . . . . . . . . 171
Eurasian (Common) Pochard . . . . . . . . . . . . . . . . 174
Redhead. . . . . . . . . . . . . . . . . . . . . . . 174
Ring-necked Duck . . . . . . . . . . . . . . . . . . . 176
Tufted Duck . . . . . . . . . . . . . . . . . . . . . 177
Greater Scaup . . . . . . . . . . . . . . . . . . . . . 177
Lesser Scaup . . . . . . . . . . . . . . . . . . . . . 178
Stiff-tailed Ducks: Multiple and World Taxa . . . . . . . . . . . . . 180
Masked Duck . . . . . . . . . . . . . . . . . . . . . 181
Ruddy Duck . . . . . . . . . . . . . . . . . . . . . 181
