Harteman Wildfowl Aviaries
Feeding ducks, geese and swans
Above, top photo: ducks feeding on duck weed.
Above, bottom photos: three types of food to provide to waterfowl.
Introduction to feeding waterfowl
This page introduces the basics of feeding wild waterfowl in aviculture: ducks, geese and swans (Anseriformes) kept in a protected environment.
The advice on this page however also applies to wild waterfowl in an urban environment, such as city parks. City ducks, geese and swans sometimes rely on the food provided by people. Please read the warning lower on this page**.
The diversity of waterfowl requires a diversity of food types and methods of providing it to them.
The type of food depends not only on the type of waterfowl, its biological needs and its natural foraging behaviour, but also on factors such as the life stage of the birds, season of the year, and of course the availability of (commercial) food products in your region.
On this page you can find some basic principles of feeding waterfowl and the choices that can be made.
Text, photos and footage by Jan Harteman
How do waterfowl feed?
How waterfowl feed is called foraging behaviour or feeding behaviour. There are as many types of foraging behaviour as there are types of waterfowl. We can roughly divide them into four groups:
Dabbling
Grazing
Filter-feeding
Diving
Feeding behaviour: Dabbling
Dabbling is a common feeding behaviour of many ducks, where they tip their heads underwater in shallow water to feed on aquatic plants, seeds, and small invertebrates, while their tails and legs remain in the air. This method is used by so called "dabbling ducks" which are also known as "puddle ducks", which contrast with typical "diving ducks" that submerge completely.
Typical dabbling ducks are those classified in the genus Anas (such as Mallard, pintails, black ducks, many teal) and genus Mareca (wigeons, gadwall, falcated duck). But this feeding behaviour is also seen in many other ducks (Mandarin, wood duck, shovelers).
This behaviour is not restricted to the above dabbling ducks only. Diving ducks (genus Aythya and Netta) often show this way of feeding and even real divers (like eiders) show this behaviour when their food source is available in shallow water.
Also, for swans the main feeding method is dabbling in the water to eat aquatic vegetation, although they also graze on land, especially in winter. To feed underwater, they submerge their long necks and heads, with their tail end in the air, to reach roots, stems, and leaves of aquatic plants. On land, they eat grasses and crops, and their diet is almost entirely herbivorous.
Above: The dabbling behaviour above is shown by Sunda teal (Anas gibberifrons) and Laysan teal (Anas laysanensis) which are typical dabbling ducks. But also Baer's pochards (Aythya baeri), which are included into the diving duck group, show their dabbling skills in this footage.
Feeding behaviour: Filter-feeding
Filter-feeding or shoveling in ducks refers to the unique surface feeding method used by shovelers to filter food from the water using their large, flat, shovel- or spatula-like bills. They sweep their heads from side to side on the water's surface, straining out tiny aquatic invertebrates, seeds, and plants through comb-like structures called lamellae inside their bills. They also often feed in pairs or large groups, circling (vortexing) to stir up food from deeper water.
Shovelers (species in the genus Spatula) are omnivores with a diet that is about 65% animal matter and 35% plant matter. Their diet includes small crustaceans, mollusks, aquatic insects, larvae, seeds, and aquatic plants.
Pink-eared ducks (Malacorhynchus membranaceus) are not shovelers, but use their spatulate like bill the same way. It is a real ecological specialist, exploiting temporary ponds and lakes of shallow saline or brackish waters of inland Australia. They eat tiny organisms from water, such as plankton, crustaceans, mollusks, and insects, which they filter through their specialized bills. They often feed in pairs by "vortexing," where they swim in a circle with one duck's head pointing to the other's tail to concentrate food. Filter feeders in the wild, these ducks are best fed using floating food trays or on the water's edge and pelleted food, crumbs, grain (wheat, millet) and green food may be fed.
Above: Pink-eared ducks, filter-feeding at Sylvan Heights Bird Park, Scotland Neck, North Carolina, USA (2016).
Feeding behaviour: Diving
Diving ducks comprise highly aquatic ducks. It includes species in several groups, with the typical diving ducks being:
- Aythya (canvasbacks, scaup, pochards)
- Netta (pochards)
But also ducks in the following genera are highly adapted for diving to find food in (deep) water:
- Bucephala (goldeneyes, bufflehead)
- Somateria (eiders)
- Oxyura (stiff-tailed ducks, ruddy ducks)
- Mergus (mergansers)
- Dendrocygna (whistling ducks or tree ducks)
- Thalassornis (white-backed duck)
- Tachyeres (steamer ducks)
- Merganetta (torrent ducks)
All of the above forage by diving deep underwater to find food like insects (Merganetta), aquatic plants (Aythya, Netta, Oxyura), mollusks (eiders, scoters, steamer ducks), and fish (mergansers, smew). They use their strong webbed feet to propel themselves underwater, sometimes aided by their wings, and may rest briefly on the surface before resurfacing.
If food sources are available in shallow water, these birds will also dabble and sometimes even shovel on the water surface.
Above: Fulvous whistling duck (Dendrocygna bicolor) diving for food, at Cologne Zoo, Germany (Photo: Jan Harteman, 2017).
Feeding behaviour: Grazing
Geese are the most typical grazers among waterfowl, with species highly adapted to graze on grasses, leaves, and shoots.
Several dabbling ducks, such as the American wigeon (Mareca americana), Eurasian wigeon (Mareca penelope) and Chiloé wigeon (Mareca sibilatrix), also graze on land, while others, like the mallard (Anas platyrhynchos) and northern pintail (Anas acuta), are opportunistic grazers when not feeding in the water.
Some geese are more specialised feeders than others. The main food source for the three species of brent geese (Branta bernicla, Branta nigricans, Branta hrota) is eelgrass and other marine algae, which they forage for in coastal areas like estuaries and saltmarshes. They also eat grasses and cereals, especially on agricultural land or amenity grasslands, a behavior that has become more common over the last few decades. In winter and during migration, their diet consists heavily of eelgrass (Zosteraca spp.) and marine algae such as sea lettuce (Ulvacap spp.). They feed on this either by grazing on exposed flats at low tide or by dabbling in shallow water.
When swans forage on land, they graze as well.
Above: A pair of blue-winged geese feeding on the grass.
What food products can I feed to waterfowl?
**CAUTION: bread is produced for people, NOT for ducks or other waterfowl; it does not meet their requirements!
Regularly feeding bread to waterfowl affects their health (malnutrition), pollutes their habitat and attracts pests.
Please provide bread only very rarely and very limited to waterfowl - or better: not at all!
Above: a bowl filled with two types of food for waterfowl. In this picture, a mixture for many types of ducks and geese: ca. 80% of this mixture contains (pressed) maintenance pellets. Ca. 20% of this mixture contains whole grains.
Complete (commercial) food products
As for captive birds, natural food sources are limited or absence, the keeper should provide complete food to their birds. Complete (processed) food for poultry is widely available in most regions of the globe, but availability of specialised (wild) waterfowl food may depend on your region.
Complete and commercial (processed) food types are divided into two categories:
- pressed pellets (in short: pellets), for distribution on land, which are suitable for most common species of ducks, geese and swans.
- extruded pellets or floating pellets (in short: floating) for distribution both in water and on land. The floating pellets are specially developed for highly aquatic species (sea ducks, eiders, mergansers, diving ducks).
Both types are widely available as a maintenance food, but also for the breeding season, or for ducklings and juveniles - it all depends on the nutrient composition.
In addition to the above, you may provide a maximum of 25% whole grain mixture to stimulate the natural feeding behavior of the birds - or even train your birds as most waterfowl find this really tasteful. Be aware grains are never a complete food source, they are an addition to their main (complete) food source.
Above: Ducklings of blue-billed teal, formerly known as Hottentot teal (Spatula hottentota), feeding on two types of food; micro floating pellets in the black bowl and duckling crumbs in the white bowl (2015).
Floating (extruded) pellets
Floating pellets are highly suited for waterfowl which mainly live and forage on water. These feeds contain fish meal and fish oil and therefore are suitable for omnivore ducks (or better: insectivores and piscivores).
There are several types of of floating pellets (extruded pellets); first there is floating pellets for mature birds and second there is starter floating pellets for juveniles/ ducklings. These types differ in size and nutrient composition.
Starter floating is highly suited for ducklings. The pellet are very small (2 mm), contain fish meal and about 22% protein.
Floating for adult birds is also appropriate fully grown (mature) ducks, geese and swans which like to feed on water. With a protein content of approx 20% and containing fish meal it is highly suited for fish and insect eating species. Sea duck floating is developed for species that need a high fish protein content, like sea ducks and eiders. This feed contains a high content of fish meal, the protein content is about 30%.
Above: If waterfowl can choose between wet and dry grains, most ducks and geese will choose for grains provided in a bowl of water - or just on the bank of the pond. The above picture shows magpie geese (Anseranas semipalmata) that prefer wet grains above dry grains (2021).
Above: Meller's ducks (Anas melleri) feeding on grains in a bowl of water.
Whole grains
Whole grains are a pure grain mix of whole wheat, sorghum (milocorn), millet, hulled oats, kardi (safflower seed) and mung beans. It is recommended for many species of (omnivorous) ducks, geese and swans to provide this as an extra (limited!) source of food, additional to their daily menu of pellets. Provide in addition to a complete feed, up to 25% of the daily menu.
This cereal mixture stimulates the function of the gizzard. Best is the mixture contains only whole grains and seeds (not ground corn or ground grains), it reduces the risk of fungal growth when dispensed in and around the water.
A good way to provide grains to your ducks, is in a bowl of water. First, it stimulates natural feeding behaviour. Second it discourages some other animals (mice, sparrows) to eat from it. You also prevent the food from spilling over a larger surface and mixing with feces, so it is more hygienic.
The major disadvantage is that, especially in warm weather, the grains deteriorate in water. So you should always offer grains in limited quantities so they are eaten quickly.
Another way to provide grain in water, is on the edge of the pond, in a shallow area. The downside is that you can never accurately measure out the amount of feed the birds completely eat, and you can't see if any food remains, which could mold or rot. The latter will also negatively affect the water quality.
What natural food sources can I feed to my waterfowl?
Above: Silver teal, also known as Versicolor teal (Spatula versicolor), filter feeding (shoveling) on duck weed (Lemna minor).
Duck weed
Duck weed (Lemna sp.) might be the best food enrichment for many ducks species, to add to the daily menu of (omnivorous) species. This includes dabbling ducks, filter-feeders (shovelers) and many diving ducks.
Duck weed is rich in protein, essential amino acids, and various minerals like calcium, phosphorus, potassium, iron, manganese, zinc, and copper. It also contains crude fiber and can be a source of omega-3 fatty acids.
An important warning that must be made is that you can only harvest duckweed in places with clean water. Because if the water is contaminated or polluted, there is a risk of poisoning your ducks!
You can grow your own duckweed to harvest and supply to your ducklings.
Some species, in addition, may thrive better on duckweed than on other sources of (processed) food. This might be the case in pygmy geese (Nettapus sp.).
An alternative for duck weed is water fern (Azolla filiculoides).
Other types of fresh green food include lettuce or chicory, but grazing waterfowl like geese and swans of course love a field of grass to feed on.
Insects and fish
Additional food types of animal matter, for omnivores or specialised carnivores (insectivores, piscivores, molluscivores) may include mealworms, small fish or shrimps.
Above: African pygmy geese (Nettapus auritus) thrive on duck weed, but only as a part of their complete menu that also contains seeds (millet) and micro floating pellets.
Above: A family of white-winged ducks (Asarcornis scutulata) feeding on water fern (Azolla filiculoides) and duckweed (Lemna minor).
Overview of different waterfowl groups and advised types of food
| Group of waterfowl | Diet categories | Feeding method | Basic commercial food type | Additional food | Food enrichment |
| Most ducks | Omnivorous (generalist) | Dabbling | Pressed pellets | Grains (max 25% of diet) | Duck weed |
| Shovelers | Omnivorous (generalist) | Filter-feeding | Pressed pellets | Floating pellets | Duck weed |
| Pink-eared duck | Omnivorous (generalist) | Filter-feeding | Millet (seeds), micro floating | Duck weed | |
| Diving ducks (Aythya, Netta) | Omnivorous (generalist) | Diving | Pellets + floating 20% protein | Grains in water | Duck weed |
| Stiff-tailed ducks (Oxyura) | Omnivorous (generalist) | Diving | Floating 20% protein | Grains in water | Duck weed |
| Pygmy geese (Nettapus) | Omnivorous (generalist) | Dabbling, plucking | Millet (seeds), micro floating | Duck weed, lettuce | |
| Mergansers, smew | Piscivore (fish), insectivore (insects) | Diving | Floating 30% protein | Mealworms, small fish | |
| Torrent ducks | Insectivore (insects) | Diving | Floating 30% protein | Mealworms | |
| Eiders, scoters, long-tailed duck | Molluscivore (molluscs, crustaceans) | Diving | Floating 30% protein | Mealworms, small fish | |
| Wigeons (Mareca) | Herbivore (grass, herbs, seeds) | Grazing | Pressed pellets | Grains (max 25% of diet) | Duck weed, green (grass) |
| Steamer ducks (Tachyeres) | Molluscivore (molluscs + crustaceans) | Diving | Floating 30% protein | Mealworms, small fish | |
| Most geese | Herbivore ( grass, herbs, seeds) | Grazing | Pressed pellets | Grains (max 25% of diet) | Green (grass, chicory, lettuce) |
| Kelp goose | Algivore (kelp, seewead), grass | Grazing | Floating pellets | + extra spirulina | Green (grass, chicory, lettuce) |
| All swans (Cygnus, Coscoroba) | Herbivore (aquatic plants, grass) | Dabbling/ grazing | Pressed pellets | Grains (max 25% of diet) | Green (grass, chicory, lettuce) |
CAUTION: bread is produced for people, NOT for ducks or other waterfowl; it does not meet their requirements!
Regularly feeding bread to waterfowl affects their health (malnutrition), pollutes their habitat and attracts pests.
Please provide bread only very rarely and very limited to waterfowl - or better: not at all!
So, how does this all effect our daily routine of feeding our waterfowl?
On a daily basis, we feed our adult waterfowl twice a day, in the morning and at the end of the afternoon. The main food we provide to most adult waterfowl (most time of the year) is a maintenance pellet (Kasper Faunafood Anseres 3).
In preparation of our ducks' breeding season, we start feeding a breeder pellet (Kasper Faunafood Anseres 4) in March, which will be their main food source in spring and summer. It is provided dry in a bowl or dispenser.
We add a small amount of whole grains to their menu, which is provided in shallow water to stimulate dabbling behaviour.
The ducklings are fed even three times a day, if necessary even more often. We provide micro floating pellets (Kasper Faunafood Anseres micro floating) or duckling crumbs, depending on the species and stage in the first weeks.
Our ducks' favourite food resource in summer is duck weed (Lemna sp.). But when duck weed is not available in winter and early spring, we provide some floating pellets on the water surface.
When the breeding season is over and the autumn starts, we change the breeder pellet again into maintenance pellete (Kasper Faunafood Anseres 3).
Above, from left to right: extruded pellets (floating), whole grains, pressed pellets.
Above: In the winter, when it snows, we should In winter, we need to be aware that food (whether offered in bowls or not) will disappear under a layer of snow. We can then offer additional food several times a day. Because of the cold, the birds generally need more energy from food, but it also gives us the opportunity to replenish any snow-covered food.
Above: In the situation above, food is provided at several spots in one aviary (on both sides of the pond). To do so, several birds can feed at more than one place at a time, which is good if there are species (or pairs) that chase each other away from the food. The feeding place in the back is covered, which keeps the food dry when it rains. This in particular is important when feeding pressed pellets. Photo taken at WWT Slimbridge (Jan Harteman, 2016).
Above: In this picture, the food we provide to our ducklings, in the first stage of rearing: waterfowl micro floating pellets.
Above: Floating food can be offered in small bowls, but can also be sprinkled loosely in the water. Be careful not to overfeed, as floating food can sink after a few hours and rot on the pond floor.
Above: White-winged ducks (Asarcornis scutulata) are not officially classified as dabbling ducks, but a great deal of their their feeding behaviour actually comprises dabbling (2023).
Above: Feeding Canvasbacks (Aythya valisineria) and Chiloé wigeons (Mareca sibilatrix).
Floating food is not only a favourite for typical divers (such as the canvasbacks), but even typical grazers (the Chiloé wigeons above) love to forage in the water now and then.
Above: Laysan teal (Anas laysanensis) and New Zealand brown teal (Anas chlorotis) filter feeding in shallow water, seeking for small food particles in the mud (2023).
Above: Feeding eiders (Somateria mollissima) at the Slimbridge Wetlands Center (Wildfowl and Wetlands Trust, 2016).
In aviculture eiders feed on floating pellets, which are provided in the water. Keeping these eiders in open (not covered) spaces, there is a chance that wild birds will feast on the (expensive) food. At the facilities of WWT Slimbridge, the floating is provided in a covered cage on the water surface, with entrance under the surface. This way the eiders will dive to their food source, but gulls and dabbling ducks are not able to reach the food.
