0 the gadwall (anas strepera) is one of the most common and widespread dabbling ducks in the family anatidae .
1  it usually frequents wetlands and dabbles for food .
2 the gadwall is 4656 cm (1822 in) long with a 7890 cm (3135 in) wingspan .
3  the male is slightly larger than the female , weighing on average 990 g (35 oz) against her 850 g (30 oz) .
4  the breeding male is  patterned grey , with a black rear end , light chestnut wings , and a brilliant white speculum , obvious in flight or at rest .
5  in non-breeding (eclipse) plumage , the drake looks more like the female , but retains the male wing pattern , and is usually greyer above and has less orange on the bill .
6 the female is light brown , with plumage much like a female mallard .
7  it can be distinguished from that species by the dark orange-edged bill , smaller size , the white speculum , and white belly .
8  both sexes go through two moults annually , following a juvenile moult .
9 the gadwall is a quieter duck , except during its courtship display .
10  females give a call similar to the quack of a female mallard but higher-pitched , transcribed as gag-ag-ag-ag .
11  males give a grunt , transcribed as nheck , and a whistle .
12 the gadwall breeds in the northern areas of europe and asia , and central north america .
13  in north america , its breeding range lies along the saint lawrence river , through the great lakes , alberta , saskatchewan , the dakotas , south to kansas , west to california , and along coastal pacific canada and southern coastal alaska .
14  the range of this bird appears to be expanding into eastern north america .
15  this dabbling duck is strongly migratory , and winters farther south than its breeding range , from coastal alaska , south into central america , and east into idaho , kansas , ohio , virginia , and then south all the way into central america .
16  its conservation status is least concern .
17 in great britain , the gadwall is a scarce-breeding bird and winter visitor , though its population has increased in recent years .
18  it is likely that its expansion was partly through introduction , mainly to england , and partly through colonization to great britain , with continental birds staying to breed in scotland .
19   it has been reported in the river avon in hampshire .
20  in ireland a small breeding population has recently become established , centred on wexford in the south and lough neagh in the north .
21 the gadwall is a bird of open wetlands , such as prairie or steppe lakes , wet grassland or marshes with dense fringing vegetation , and usually feeds by dabbling for plant food with head submerged .
22  it nests on the ground , often some distance from water .
23  it is not as gregarious as some dabbling ducks outside  the breeding season and tends to form only small flocks .
24  this is a fairly quiet species; the male has a hoarse whistling call , and the female has a mallard-like quack .
25  the young birds are fed insects at first; adults also eat some molluscs and insects during the nesting season .
26  the gadwall is one of the species to which the agreement on the conservation of african-eurasian migratory waterbirds (aewa) applies .
27 this species was first described by linnaeus in his systema naturae in 1758 under its current scientific name .
28 the gadwall's closest relative within the genus anas is the falcated duck , followed by the wigeons .
