Ducks are omnivorous foragers, consuming both plant and animal matter. Their diet varies significantly based on species, habitat, and seasonal food availability.
What Ducks Naturally Eat
Ducks’ diet includes aquatic vegetation like algae, duckweed, pondweeds, water lilies, wild rice, wild celery, coontail, milfoil, widgeon grass, sedges, and rushes. Dabbling ducks (e.g., mallards) feed by tipping forward for submerged plants in shallow waters. Diving ducks (e.g., canvasbacks) propel themselves underwater for roots and tubers in deeper areas.
Ducks also consume various invertebrates. Their diet includes insects like water beetles, dragonfly nymphs, mosquito larvae, grasshoppers, and ants, along with worms, snails, slugs, and crustaceans such as crayfish and freshwater shrimp. These protein sources are important for energy during breeding season. Some species also consume small vertebrates like fish, tadpoles, and frogs.
Seeds and grains from wild grasses and wetland plants, including acorns and wild rice, are significant, especially when other food sources are scarce. They may also forage in agricultural fields for spilled corn, wheat, barley, or millet. Their beaks are adapted for diverse feeding strategies; broad, flat bills with comb-like lamellae filter small food particles, while some have specialized bills for grasping fish or prying shellfish.
Foods to Avoid Feeding Ducks
Many common human foods harm ducks’ health and the environment. Processed items like bread, crackers, chips, and pastries offer minimal nutritional value, primarily carbohydrates, lacking essential proteins, vitamins, and minerals. These “junk foods” can lead to malnutrition and obesity, filling ducks’ stomachs without providing necessary nutrients.
Poor-quality foods can cause severe health issues, including “angel wing.” This condition causes a duckling’s wing joints to develop improperly, twisting feathers outwards. Often irreversible, it results from nutritional deficiencies and excessive carbohydrates, preventing flight and making the bird vulnerable. Uneaten bread and discarded foods also pollute waterways, leading to algal blooms and fostering harmful bacteria like those causing avian botulism.
Certain processed human foods contain toxins directly harmful to ducks. These include:
- Chocolate (contains toxic methylxanthines and theobromine)
- Avocado (contains persin, fatal to ducks)
- Onions and garlic (contain thiosulfates that cause digestive problems)
- Citrus fruits (interfere with calcium absorption, leading to brittle bones and thin eggshells)
- Salty junk foods (can cause salt overdose)
- Moldy or spoiled foods (can lead to bacterial and fungal infections like aspergillosis)
Improper feeding creates broader ecological problems. Ducks become dependent on human handouts, losing natural foraging skills and fear of people, increasing vulnerability to predators and accidents. Overcrowding leads to increased aggression and rapid disease spread. Uneaten food attracts pests like rats and mice, disrupting the local ecosystem.
Responsible Supplemental Feeding
For supplemental feeding, selecting appropriate options and responsible practices is important. Safe alternatives that align with a duck’s natural diet include:
- Defrosted frozen peas
- Fresh or cracked corn
- Plain rolled oats
- Unsweetened birdseed mixes designed for wild birds
- Chopped leafy greens (romaine lettuce, spinach, kale, cabbage, watercress)
- Cooked plain rice
- Commercial duck pellets
Treats should be no more than 10% of a duck’s daily intake to prevent nutritional imbalances. Scattering food in water encourages natural foraging and prevents large piles from attracting pests or polluting. Avoid hand-feeding; it can habituate ducks to humans, leading to aggressive behavior and loss of natural wariness.
Wild ducks find all the food they need in their natural habitats. Supplemental feeding is not necessary for their survival. Avoid feeding ducks during breeding seasons or when well-fed, as continuous food provision can lead to overpopulation and increased competition for resources.