Flooding can have a significant impact on waterfowl like mute swans and mallards in several ways:
1. Loss of habitat
Flooding can submerge nesting areas and feeding grounds, making it difficult for waterfowl to find suitable places to nest, feed, and rest. This is especially crucial during breeding season when nests can be destroyed by rising waters, causing the loss of eggs or chicks.
2. Displacement
Waterfowl may be forced to relocate to areas with less flooding, often moving to unsuitable or overcrowded locations. This can lead to increased competition for food and territory, as well as stress on the birds. Swans, being territorial, may find it challenging to maintain their usual space.
3. Food shortage
Floodwaters can alter the availability of food sources. For instance, submerged vegetation may become inaccessible to grazing swans, and floodwaters may also wash away aquatic plants and small invertebrates that ducks like mallards rely on. Turbid waters may also disrupt the ability of waterfowl to see and catch food.
4. Health issues
Flooding can increase the spread of waterborne diseases like botulism, which waterfowl can contract through contaminated water or food sources. Floodwaters can also carry pollutants, sewage, or chemicals into habitats, further increasing health risks.
5. Increased predation
Flooding can make waterfowl more vulnerable to predators. With less cover for protection, birds like mallards may struggle to hide from land-based predators or even birds of prey. Additionally, flood-displaced birds may become more exposed in unfamiliar areas.
6. Disruption of breeding cycles
For species like mute swans, whose nesting season is highly dependent on stable, shallow waters, flooding can disrupt breeding by washing away nests or flooding low-lying areas where they would usually raise their young.
7. Exhaustion and injury
Swans and ducks displaced by floods may have to travel greater distances in search of safe ground. This can lead to exhaustion or even injury, particularly in areas where access to safe, unpolluted water is limited.
In short, while waterfowl are naturally adapted to living in wet environments, severe and prolonged flooding can put immense pressure on them, affecting their survival and well-being.