There are certain species which just fit into each category and without them there would be a gap.  How could there be a coast section without Puffin, or a mountain section without Ptarmigan.  Likewise one of the species which is recognisable as a water bird is the Heron.  Worldwide there are 64 different species of Heron and the one we have in Britain is the Grey Heron which is a big bird growing up to one metre in height.  Not popular with garden pond owners, it has the ability to stand motionless for long periods of time fishing and can over the period of a few days empty a pond of its contents. 

As well as in gardens, it can be seen in parks, and a wide cross section of water habitats, it is one of the largest and most recognisable water birds.  The Grey Heron is found over a wide geographic area across Europe, and fairly large parts of both Africa and Asia.  It is a migratory bird and numbers increase during the Autumn and winter months, it is thought about 15,000 birds breed in Britain but 60,000 birds spend the winter here.