a web page by Don Roberson
  • 158 species worldwide
  • DR personal total: 114 species (72%), 83 photos
The Anatidae — a huge family that includes ducks, geese, and swans — are strongly associated with water habitats around the world. The family has great diversity in size, shape, color, and behavior. Black Swan (above; adult with young) frequents open lakes in Australia. Hooded Merganser (male, left) prefers quiet, wooded ponds in North America; it rather rarely raises its impressive crest. Huge flocks of Snow Goose and Ross's Goose migrate from the northern tundra to winter together in places like California's Central Valley. The noise of flock like this taking off (below) can be deafening. Many of these refuges were created by hunting interests, but now attract birders to enjoy the spectacle.
Ducks have a wide variety of strategies for survival. Some species are mostly sedentary, like African Pygmy-Goose of the African tropics (above). Others are comparatively short distance migrants, such as Blue-winged Teal within interior North America (right). Yet others are spectacular long-distance migrants. Smew, a small merganser that breeds in the high Palearctic, is an example. Species with long migratory routes will spin off vagrants to delight the birding world. This male Smew (below) appeared briefly in mid-winter in the foothills of California's Sierra Nevada range for two winters running. In my shot the Smew was just crossing a patch of water with impressive reflections of the far shore.
Waterfowl as a family is a noncontroversial concept, but there has been a lot of debate about the arrangement of the subfamilies and tribes within the family, and about the relationship of the Anatidae to other families. The Handbook of the Birds of the World (Carboneras 1992) sets up 3 subfamilies and 12 tribes, but one of those subfamilies is Magpie-Goose, which many recent authorities (e.g., Dickinson 2003) and I treat as a separate family [Anserantidae].

Dickinson (2003) divides the Anatidae into 5 subfamilies:

  • Dendrocygninae [whistling-ducks; represented by Spotted Whistling-Duck, above left]
  • Anserinae [swans & most geese, Brant, above right]
  • Stictonettinae [Freckled Duck Stictonetta naevosa of inland south Australia; no photo]
  • Tadornine [shelducks, torrent ducks, aberrant geese, like Spur-winged Goose (right)]
  • Anatinae [puddle & diving ducks, eiders, scoters, stifftails & mergansers (Common Merganser with brood, below)

There are other arrangements, and the final word is likely not yet in on this topic.

In many ducks there is strong sexual dimorphism, with males sporting conspicuous and classic patterns most of the year (except for a brief "eclipse" plumage during wing-molt) and females often dressed in camouflage patterns. In many species males are promiscuous and do not share any of the duties of raising young. "Rape" is a common behavior in many of the "puddle ducks" (like Mallard Anas platyrhychos).

Here in North America we tend to divide our standard freshwater species into the 'puddle ducks,' such as Northern Shoveler (above) and the 'diving ducks,' like Ring-necked Duck (below). These two groups forage in different ways, which makes 'puddle ducks' common in shallow, weedy ponds with 'diving ducks' typically restricted to deep-water venues. The Wood Duck (right) is neither; it is a distinctive species on its own, breeding in old woodpecker holes in dead trees in riparian areas, or in nest-boxes now put up widely for its protection.

To this point the photos have been mostly of freshwater ducks, but there is an impressive selection of salt-water species. The scoters, represented by Surf Scoter (above), are primarily mullusk-eaters. This young male has a large clam.

Harlequin Duck (male & female, left) migrate substantial distances between breeding and wintering grounds. Some nest along rushing mountain streams, but they winter on salt water. Long-tailed Duck (imm. male, below) breeds even farther north in the Arctic tundra and may have the longest migration route of any duck.

Some of all the most impressive waterfowl are the cascade specialists — those ducks that spent their lives in and by rushing streams in the Andes or Australasian mountains. Incredible swimmers with elongated bodies and long maneuverable tails, somehow they are at home in the swiftest of currents. I've been fortunate to observe all of them in habitat. The Torrent Duck (left) is silhouetted against the turbulent Urubamba River in the Peruvian Andes; a close-up of the same shot (inset left) proves it to be a white-headed male.

The other cascade specialists are Blue Duck Hymenolaimus malacorhynchus of New Zealand and Salvadori's Teal Salvadorina waigiuensis of New Guinea. I've had the good fortune to watch both working the rapids of roaring rivers in the mountains of those islands.

Because many species of waterfowl are long distance migrants, there is the possibility for vagrants. Usually one must go to the far north to see Steller's Eider, for example. This pair (above left) were flying past St. Lawrence Island in the Bering Sea. That is a very special duck, but it is even more dramatic when one appears far south, just as this imm. male (above right) that appeared in the Crescent City harbor between Jan-May 1983 (this photo taken in pouring rain).

Vagrant waterfowl present a variety of problems. First, one must evaluate whether the bird is a wild vagrant or an escape for captivity; this Trumpeter Swan in Texas (right) presented exactly that problem. Second, identification of vagrants requires caution. Issues in identifying white swans in North America have caused many problems; see Banko (1980), Bailey (1991), and Patten & Heindel (1994). Other local California problems have been addressed by such papers as Wallace & Ogilvie (1985), Tobish (1986), Jackson (1992, 1993), or Martin & DiLabio (1994). All these papers are much better resources that 'standard' family tomes (e.g., Palmer 1976 or Madge & Burn 1988) for identifying vagrants.

Finally, issues of hybridization are legion. Gillham et al. (1966) & Gillham (1987) cover some of the many problems.

There are a set of waterfowl, usually placed right at the end of the family chronology, called stifftails. Ruddy Duck (male with a brood behind; below left) can be brilliant in summer and does impressive chin-bobbing displays in courtship. This species cruises out into open water and is easy to view. In contrast, Masked Duck of the Neotropics (below right) is a skulker, hiding in the reeds, and can be difficult to locate (Lockwood 1997). This particular one, though, was a vagrant to Florida at a locale where hiding spots were limited.

Photos: The Black Swan Cygnus atratus with brood was on Lake Ballarat, Victoria, Australia, in Nov 1983. The male Hooded Merganser Lophodytes cucullatus was in Carmel Valley, California, on 7 Dec 2004. The flock of Snow Goose Chen caerulescens & Ross's Goose C. rossii was at Merced NWR, California, in 26 Dec 1999. The African Pygmy-Goose Nettapus auritus was on Lake Bisini, Uganda, on 30 July 2004. The pair of Blue-winged Teal Anas discors were at Vierra, Florida, on 21 Dec 2006. The vagrant male Smew Mergellus albellus was in Tuolumne Co., California, 28 Jan 2007. The Spotted Whistling-Ducks Dendrocygna guttata were at Port Moresby, Papua New Guinea, on 14 Oct 1983. The "Black" Brant Branta bernicla nigricans was at Monterey, California, on 17 Feb 2007. The Spur-winged Goose Plectropterus gambensis was at Lake Jipe, Kenya, on 26 Nov 1981. The female Common Merganser Mergus merganser with brood was on the Big Sur River, California, on 7 June 2008. The flock of Northern Shoveler Anas clypeata was at the south end, Salton Sea, California, on 14 Apr 2006. The male Wood Duck Aix sponsa was at Santee Lakes, near San Diego, California, on 10 Apr 2008. The male Ring-necked Duck Aythya collaris was in Tuolumne Co., California, on 27 Jan 2007. The imm. male Surf Scoter Melanitta perspicillata and Long-tailed Duck Clangula hyemalis were at Moss Landing, California, on 5 Mar 2008. The pair of Harlequin Duck Histrionicus histrionicus were in the Monterey harbor, California, in Jan 2007. The Torrent Duck Merganetta armata was seen from the train down the Urubamba River to Machupicchu, Peru, in July 1987. The pair of Steller's Eider Polysticta stelleri were at Gambell, St. Lawrence I., Alaska, on 4 June 1980; the vagrant imm. male was at Crescent City, California, on 9 Feb 2003. Greg W. Lasley photographed the adult Trumpeter Swan Cygnus buccinator, which may or may not be a wild vagrant, at Kerr Co., Texas, in Feb 1999. The male Ruddy Duck Oxyura jamaicensis was in Sierra Valley, California, on 22 June 2006. The female Masked Duck Oxyura dominica was at Vierra, Florida, on 21 Dec 2006. All photos © D. Roberson, except the Trumpeter Swan © Greg W. Lasley, and used with permission; all rights reserved.

Bibliographic essay:

Family Book:
Madge, Steve & Hilary Burn. 1988. Waterfowl: An identification guide to the Ducks, Geese and Swans of the World. Houghton Mifflin, Boston.

This was one of the first "compact" family books which would set a pattern to be followed by all too many of those that followed: sets of color paintings together in the front with facing pages of brief text and map, and then detailed species accounts forming the back half of the book. The plates here are fairly nice and not so rigidly "field-guide art" and some later examples, but still one gets little sense of the habitat of each species in the artwork. The text is aimed primarily at identification topics with sections on habitat, distribution, and movements. This book — indeed, this type of book — is okay for an introduction to the topics covered, but it is too small to be thorough. I will still turn to the Birds of Western Palearctic series, or the relevant volumes of the unfinished Palmer's Handbook of North American Birds, for detailed plumage descriptions and molt schedules [and, since this review was written back in 1999, I would not turn to the relevant fascicle in the Birds of North America series]. Detailed and well-illustrated identification articles (hopefully with photos) are still required to identify vagrants. It is thus quite difficult to decide exactly what the Madge & Burn book is good for, except for a quick & comparatively accurate summary of the world's waterfowl.

Family Book:
Todd, Frank S. 1979. Ducks, Geese, and Swans of the World. Seaworld, San Diego.

A different sort of book than Madge & Burn, this is meant to be a "coffee table" book of lovely photos and an introduction to the variety in the family. It serves these purposes well. The photos are very nice and an effort has been made to cover every species (even a few specimens when that was all there was). There is an especially useful appendix for birders which summarizes the status of each species in captivity in North America. This helps immensely in getting a feel of whether the wayward duck you've just discovered could be a wild vagrant or is just an escape from a captive collection.

Literature cited:

Bailey, S.F. 1991. Bill characters separating Trumpeter and Tundra swans: a cautionary note. Birding 23: 89-91.

Carboneras, C. 1992. Family Anatidae (Ducks, Geese & Swans), pp. 536 –630 in Handbook of the Birds of the World (del Hoyo, J., A. Elliott & J. Sargatal, eds). Vol. 1. Lynx Edicions, Barcelona, Spain.

Banko, W.E. 1980. The Trumpeter Swan. Univ. of Nebraska Press, Lincoln.

Gillham, E.H. 1987. Tufted Ducks in a Royal Park. E. Gillham, Romney Marsh, Kent, England. [An absolutely great bird on plumage variation, hybridization, molt schedules, and biology of Tufted Duck. Because it was published privately, it has been overlooked much too often.]

Gillham, E.H., Harrison, J.M., and Harrison, J.G. 1966. A study of certain Aythya hybrids. Wildfowl Trust Annual Report 17: 49-65. [The absolutely classic work on this topic.]

Jackson, G.D. 1991. Field identification of teal in North America, female-like plumages. Part I: Blue-winged, Cinnamon, and Green-winged Teal. Birding 24: 214-223.

Jackson, G.D. 1992. Field identification of teal in North America, female-like plumages. Part II: Garganey and Baikal Teal. Birding 24: 214-223.

Lockwood, M. W. 1997. A closer look: Masked Duck. Birding 29: 386-390.

Martin, P. R., and B. M. DiLabio. 1994. Identification of Common X Barrow's Goldeneye hybrids in the field. Birding 26: 104-105.

Palmer, R.S., ed. 1976. Handbook of North American Birds. Vols. 2 & 3. Yale Univ. Press, New Haven, CT.

Patten, M.A., and M.T. Heindel. 1994. Identifying Trumpeter and Tundra Swans. Birding 26: 306-318.

Tobish, T. 1986. Separation of Barrow's and Common goldeneyes in all plumages. Birding 18: 17-27.

Wallace, D.I.M., and M.A. Ogilvie. 1985. Distinguishing Blue-winged and Cinnamon teals, pp. 267-271 in Sharrock, J.T.R., ed. The Frontiers of Bird Identification. British Birds, Ltd., Biggleswade, U.K.




  page created 21 Feb 1999, revised 30 June–4 July 2008  
all text & photos © Don Roberson, except as otherwise indicated; all rights reserved