A duck is a bird that spends a lot of time in the water or near habitats where there is a lot of water. There are other birds that also exhibit the same nature such as swans, geese, coots and many more. All these birds, including ducks are collectively known as waterfowl.  

Speaking of ducks one cannot but mention that it is a very large group among waterfowl. This group has two subcategories known as Dabbling Ducks and Diving Ducks. Of the two, the dabbling ducks get their name because they feed by dabbling in shallow muddy water. The other type, the diving ducks find their food by swimming and diving in the water.  

Dabbling and diving duck groups include 15 and 20 different types, respectively.  They are popular game birds. This is one reason why identification of ducks is necessary. Another reason is their study. Ornithologists may want them identified for serious scientific study while bird watchers may want them to be identified for pleasure and for knowledge.  But, the large number of different types of ducks makes their identification difficult. The problem becomes more difficult because ducks are usually seen in mixed groups and there is a tendency among them to mix breed or hybridize.

How to identify ducks? Ducks can be identified by their physical features, habits and habitats. It is necessary to have a good pair of binoculars and a camera with zooming capabilities. It is also useful to take down notes on the ducks' physical characteristics by examining their size, bill, head, neck, plumage, legs and tail. Similarly, noting down their habits such as the feeding and flocking behavior. The sounds they make are also important. Observing the features of their range and habitats is also a must. The next important thing to do is taking pictures.

Pictures of ducks are a very useful tool in identifying ducks. There are quite a number of online resources that contain pictures of various types of ducks with identification facts. These can be used to compare with the pictures that were taken in the field. The identification facts that are supplied with the pictures can be compared with the notes that were made during field observations. With such comparative studies of duck identification pictures and notes one can safely come to a conclusion about the identity of a duck. 

For further confirmation, the identification pictures can be sent to an authority on the subject. These resources are also available on line.