Goosanders are part of a genus of ducks that includes the similar Merganser, fish-eating specialists known as “sawbills”. The name is apt, as the bill has a row of serrations, almost like teeth, that help it grip fish it catches when diving.
They are so highly specialised for life on and in the water that they rarely come onto land, other than to nest. Their bodies are not well suited to land, their legs are quite far back on the body and they therefore tend to overbalance.
In the water is a different matter, and they will first ‘snorkel’, swimming along with their head under the water spotting fish. When they see prey they dive, and swim powerfully, grabbing fish in their bill.
I’ve referred to them as fish specialists, but like most birds they can and will take other food sources when necessary, whether it’s invertebrates like worms, or even up to small mammals and other birds.
They will often be seen in groups, and in winter these can include substantial numbers. Winter flocks tend to see males that have bred off in one ‘bachelor’ group, while the females and that year’s young occupy another group. They then all come back together in Spring.
The two are easily distinguished, the male is larger with a shiny green head and predominantly white body. The female is greyer, and has a rusty orange head. This sort of difference is called ‘sexual dimorphism’.
Over the past decade I’ve noticed they are becoming more common in urban settings, and on the River Kent in Kendal I’ve even seen them come to the water’s edge with mallards to take food thrown by people. It’s a great chance to observe such a striking bird, and its wonderful evolutionary adaptations, up close.