Jan 24 - 30: Ducks, Geese and relatives (Anseriformes)
This week on the Critter Calendar we moved from soaring raptors to the aquatic birds of the order Anseriformes - ducks, geese, swans and screamers.
Counting some of the most familiar and iconic birds in the world as members, the Anseriformes are well adapted to living life at the water’s surface. They all have webbed feet for powerful swimming, most have special oils which protect their feathers from water, and their bills have special filters, called lamellae, which help them feed on the plants that make up most of their adult diets
Nearly all Anseriformes belong to the family Anatidae, which includes the ducks, geese and swans. Dabbling ducks, like the ubiquitous Mallard, tend to feed in shallower waters where they can upend themselves to feed on shallow aquatic vegetation, their hindquarters sticking above the water’s surface. Diving ducks such as Ring-necked duck tend to submerge their entire bodies when searching for food, and have larger feet than dabblers. Many ducks are sexually dimorphous - males often have bold colors and patterns, while females are usually drab in plumage. The Paradise Shelduck is a notable exception to this pattern.
Geese and swans of the subfamily Anserinae are bigger than ducks and have longer necks. Large Mute Swans are known to have wingspans reaching 3 m (9.8 ft) and may weigh 15 kg (33 lbs). Geese and ducks can often be found feeding on terrestrial vegetation.
The family Anhimidae, or “screamers,” consists of three species who live in South America. More terrestrial than the Anatidae, their feet are only partially webbed and their bills are more pointed than flattened. Bizarrely, they have air bubbles in their skin which supposedly make crackling noises when pressed!
Guinea and Northern Australia are home to the lone species of this family, the Magpie Goose. Their bill shows they belong in the Anseriformes but are considered an early offshoot within the order. Magpie geese have black and white plumage, yellow legs, and can congregate in large groups during breeding season.
If you think you see any of these this week, share your observations with us. We’ll be keeping track here. Happy Anseriforme hunting!
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