When swimming, a duck is only a sixth as efficient as an average ship at utilising energy.
There is a statue of a duck at Freiburg in Germany, erected in memory of its alerting the population to an imminent air raid in 1944.
The effectiveness of this warning may be judged from the result of a later noise abatement court case in Germany, at which experts testified that 10 quacking ducks make as much noise as three motor lorries with trailers.
No research seems to have been done into the question of whether German ducks are noisier than Canadian ducks, but, when Milutin Velkjovic set a new world record in 1970 by being buried for 463 days, he spent his time underground accompanied by two Canadian ducks.
In a storm in Arkansas in 1974, people were pelted by frozen ducks, killed by a sudden blast of cold air across their flight path.
The total number of ducks in the world has been estimated as 580 million, which is less than one duck for every 10 people.
Around 27 per cent of them are in Vietnam, which is more than in any other country except China.
There are 13.3 ducks per rood on the campus of York University, by far the highest density of ducks at and English university.
The first duck to receive a protection order in New York State's Suffolk County was a pet named Circles.
The order was made by a court after the duck was shot with a pellet gun by a neighbour.
Donald Duck's middle name is Fauntleroy.