THE WORLD BIRDS - An Online Bird Book
WATERFOWL - Diving Ducks
The term waterfowl is used to describe any member of the order Anseriformes. A series of articles describes all the waterfowl. This specific article describes the
"diving ducks " which belong to family Anatidae, subfamily Aythyinae.
Anseriformes
Most species of the order Anseriformes spend a considerable amount of time in water. In fact, they are called waterfowls. Their webbed feet make for efficient swimming. A few species spend little time in water and thus their feet are only partially webbed. Most waterfowl are also good flyers, many migrating long distances to escape the cold and others migrating shorter distances for optimizing their food supply. All species, except the screamers, have a wide and relatively flat bill. The shape of a species bill and also their tongue is a function of their diet. Considering the entire order, they eat aquatic plants, grasses, sedges, algae, plankton, insects, insect larvae, mollusks, crustaceans, fish, fruits, grains, rice. Most species are monogamous and if they lose a partner seem to mourn. Males are larger and heavier than females. The chicks are well developed when they hatch and can walk almost immediately.
The order
Anseriformes has 3 familes: Anatidae, Anhimidae, Anseranatidae. Family Anatidae is comprised of the ducks, swans, and geese which amounts to about 160 species. Family
Anhimidae is made up of 3 screamer species while family
Anseranatidae has only one species, the magpie goose. Since these latter two families contain so few species, it seems appropriate to consider the entire order in this series of articles.
Anatidae
The Anatidae family has the following subfamiles:
Anatinae: dabbling ducks and
teals
Anserinae: geese, swans
Aythyinae: diving ducks
Dendrocygninae: whistling ducks
Merginae: sea-ducks
Oxyurinae: stiff-tailed ducks
Plectropterinae: spur-winged goose
Stictonettinae: freckled duck
Tadorninae: shelducks, shelgeese
Diving Ducks
The diving ducks, commonly called pochards or scaups, are a category of duck which feed by diving beneath the surface of the water. They are mainly found in the northern hemisphere. To aid in their swimming under water for food, diving ducks tend to be denser than dabbling ducks, have large heads, and their legs placed further back on their body. Must are shallow divers, but the greater scaup will dive up to 6 meters (20 ft). They are ungainly walking on ground and their takeoff for flying is labored. The diving ducks are placed in 4 genera, with the majority of the 17 species place in either Aythya or Netta. Those in Netta tend to "dabble" more often then dive, but are still referred to as diving ducks.
All diving ducks live near water and do most of their foraging at waterbodies. Shallow wetlands are preferred, but most important is that there is abundant vegetation, both submerged and emergent. During the breeding season, freshwater is almost exclusively visited. During the winter season, brackish and saline wetlands are added to the sites of many of the diving species.
Some diving ducks are mainly vegetarians eating roots, tubers, green mateiral seeds. Others eat more animal material than vegetable. These diets includes aquatic insects and their larvae, mollusks, small fish, snails, crustaceans. The tendency to be non-vegetarian is greater in the breeding season because a higher protein diet can be required by juveniles and also mothers.
All diving ducks are strong flyers and those that live in the northern hemisphere are migratory; breeding in more northern climates and wintering where it is warmer and the vegetations still growing. The few that live in the southern hemisphere are generally non-migratory. The white-eyed duck of Australia will travel to avoids droughts. The New Zealand scaup will move if the ponds freeze. The rosy-billed pochard of South America is partially migratory, those birds in the southern part of the continent do migrate to warmer climates in the winter. The southern pochards of both South America and Africa are mainly sedentary, but move some during droughts.
The males of these species average larger than the females. The also exhibit dimorphism - the sexes look very different. During breeding season their looks differ the greatest. that way a female has no trouble telling the difference between a mature male and a juvenile. The diving ducks have two exceptions: the teal duck and the white-winged duck are not dimorphic.
Pair of Tufted Ducks Image by Dick Daniels
Genus Aythya
Canvasback Aythya valisineria
Image by: 1)
Judy_Gallagher - Maryland
2, 3, 4) Dick Daniels -
Sylvan Heights
1, 2) Female 3, 4) Breeding male
Duck,_Ferruginous Aythya nyroca
Image by: 1)
GrahamC57 - England 2,
3) Dick Daniels -
Sylvan Heights 4)
Imran_Shah - Pakistan
1, 2) Female 3, 4) Male
Duck, Ring-necked Aythya collaris
Image by:
1, 2) Alan D Wilson - Near San Diego, California 3)
Hilary Chambers - United Kingdom 4)
Chad King
1 - 3) Female 4 - 6) male
Duck, Tufted Aythya fuligula
Image by: 1) Namisao 2, 3) Dick Daniels -
Sylvan
Heights 4)
Imran_Shah - Pakistan
1) Female 2) Eclipse maile 3, 4) Male
Duck, White-eyed Aythya australis
Image by: 1)
JJ_Harrison 2 ) Oystercatcher 3
) Dick Daniels -
Sylvan
Heights
4)
Dick Daniels - Featherdale Wildlife Park, Australia
1, 2) Female 3, 4) Male
Pochard, Baer's Aythya baeri
Image by:
1, 2)
Dick Daniels -
Sylvan Heights
1, 2) Male
Pochard,_Common Aythya ferina
Image by: 1)
sebastien_bertru - France 2)
Imran_Shah - Pakistan
3) Jan_Svetlik 4)
Richard Barrett-Small
1, 2) Female 3, 4) Male
Pochard,_Madagascar Aythya innotata
Image by: 1)
Amy AcAndrews 2, 3) Frank Vassen
1) Female in front
2, 3) Male
Redhead Aythya americana
Image by:
1, 2,
3) Dick -
Sylvan
Heights 4) Dick Daniels -
Flamingo Gardens, Flroida
1, 2) Female 3, 4) Breeding males
Scaup, Greater Aythya marila
Image by:
1, 3) Len Blumin - California 2)
Shanthanu Bhardwaj - Illinois 4)
Calibas - California
1) Pair 2) Female 3) Male in eclipse 4) Male
Scaup, Lesser Aythya affinis
Image by: 1)
Dick Daniels -
Sylvan Heights 2)
New Jersey Birds - California 3)
Len Blumin - California 4)
Rich Leche
1, 2) Female 3,4) Male
Scaup,_New_Zealand Aythya novaeseelandiae
Image by: 1)
Arthur_Chapman 2)
Dick Daniels - Sylvan Heights
3) Dick Daniels-
Sylvan Heights 4 Dick - New Zealand
1, 2) Female 3, 4) Male
Genus Netta
Netta is a genus of diving ducks. Unlike other diving ducks, the Netta species are reluctant to dive, and feed more like dabbling ducks.
Netta ducks do not walk on land as well as dabbling ducks because their legs are placed further back for efficient swimming.These are gregarious ducks, mainly found on fresh water. They are strong fliers, but their broad, blunt-tipped wings require faster wing-beats than those of many ducks and they take off with some difficulty.
Pochard,_Red-crested Netta rufina
Image by: 1)
4028mdk09 2, 3)
Dick Daniels -
Sylvan Heights 4)
Ken_Billington
1, 2) Female 3, 4) Male
Pochard,_Rosy-billed Netta peposaca
Image by: 1) )Nick Athanas - Argentina 2)
Rachid_H 3)
Sandy Cole -
Sylvan Heights 4)
Dick Daniels -
Sylvan Heights
1, 2) Female 3, 4) Male
Pochard,_Southern Netta erythrophthalma
Image by: 1)
Regani 2, 3)
Dick Daniels -
Sylvan Heights 4)
Leo_za1
1, 2) Female 3, 4) Male
Genus Marmaronetta - 1 species
Duck, Teal Marmaronetta angustirostris
Image by:
1, 2)
Dick Daniels -
Sylvan Heights 3)
Sandy Cole -
Sylvan Heights 4) Cristiano Crolle - Racconigi, Italy
Genus Asarcornis - 1 species
The white-winged duck was formerly include with the muscovy duck in genus
Cairina. However it now thought to be closer to diving ducks. It is a very large duck, slightly bigger than the muscovy.
Duck, White-winged Asarcornis scutulata
Image by:
1, 2, 3, 4) Dick -
Sylvan Heights