Tundra Swan - Ecology

Ecology

In summer, their diet consists mainly of aquatic vegetation – e.g. mannagrass (Glyceria), Potamogeton pondweeds and marine eelgrass (Zostera), acquired by sticking the head underwater or upending while swimming; they also eat some grass growing on dry land. At other times of year, leftover grains and other crops such as potatoes, picked up in open fields after harvest, make up much of their diet. Tundra Swans forage mainly by day. In the breeding season, they tend to be territorial and are aggressive to many animals who pass by; outside the breeding season they are rather gregarious birds.

Healthy adult birds have few natural predators. Arctic Foxes (Vulpes lagopus) may threaten breeding females and particular the eggs and hatchlings; they can be quite hard to scare away. Raccoons (Procyon lotor), very common in Canada, East Asia and Europe, eat eggs and young on occasion. About 15% of the adults die each year from various causes, and thus the average lifespan in the wild is about 10 years. The oldest recorded Tundra Swan was over 24 years old.