Geese do not eat ducks; they are not predators. The confusion arises from frequent aggressive interactions between the two species of waterfowl. Geese are large, herbivorous birds whose intimidating behavior is often mistaken for hunting. Their highly territorial nature leads them to chase and attack other birds, including ducks, to defend their space and offspring.
The Herbivorous Diet of Geese
Geese are primarily herbivorous animals. They spend a significant portion of their day grazing on grasses and other terrestrial vegetation, using their strong bills with serrated edges to efficiently tear and consume plant material. Fresh grass is a major component of their nutrient intake.
The remainder of their diet consists of various aquatic plants, such as pondweeds, algae, and water milfoil, which they forage for near the water’s surface. During the fall and winter, their food sources shift to include grains, seeds, and berries to store energy for the colder season. While they occasionally consume small invertebrates like insects or worms to supplement protein, these items make up a minor, opportunistic fraction of their overall food consumption. The physiology and feeding strategy of geese are not adapted for hunting or eating larger prey like ducks.
Territoriality and Aggressive Waterfowl Behavior
The aggressive behavior witnessed between geese and ducks is a demonstration of territorial defense, not a search for food. Geese, particularly males, become intensely territorial during the mating and nesting seasons, which typically occur in the spring. This heightened aggression secures and protects prime nesting sites and resources from perceived threats or competitors.
A goose signaling a threat will display body language including hissing, stretching its neck low to the ground, and rapidly flapping its powerful wings. The target of this aggression can be anything from humans and dogs to other waterfowl, including ducks and gulls. These displays are intended to intimidate rivals and drive them away from the immediate area surrounding the nest or their goslings. Competition for space and resources in shared habitats is the primary driver behind these attacks.
When Geese Attack Ducklings
While geese are not predators of ducks, they sometimes exhibit extreme aggression that can result in the injury or death of ducklings. This lethal outcome is a result of hyper-territorial dominance. An adult goose, being significantly larger and stronger than a duckling, can easily subdue or kill the smaller bird through repeated pecking, biting, or drowning.
These violent interactions are distinct from regular, non-lethal territorial displays between adult birds. In these rare instances, the goose’s goal is to eliminate a perceived competitor for food or space, or to remove a potential threat to their own offspring. Even when a duckling is killed, the goose does not eat it, confirming that the motivation is aggression and dominance, not feeding behavior.