Frequently encountered in regions abounding in lakes and rivers is the common or grey heron, Ardea cinerea, a bird the size of a small stork. It is grey above, with a white neck dotted with dark longitudinal spots in front and with elongated plumes on the neck. Running above the eye to the back of the head is a wide, black band. Adults have a small crest on the nape. The great blue heron, Ardea herodias, a widespread American species ranging from Canada to Argentina, is virtually identical in appearance and habits.

Common herons generally nest in colonies, often together with other species. The nests are often located close to the surface of the water, though they may also be found in the top branches of tall trees or among reeds and on cliffs by the sea. The nesting site is selected by the male, who then starts his courting. After he has found a mate, the two build the nest together. The courting, building of the nest and alternating of the two on the nest is accompanied by various ceremonial displays in which stance, ornamental feathers and voice play the chief roles.

The clutch comprises 3-5 blue-green eggs which are incubated by both the male and female, in 4-6 hour shifts for 25-28 days; after hatching they continue to shelter the young from inclement weather. Strong downpours and cold take the greatest toll of the young. At first, the parents feed their offspring by placing regurgitated food directly into their beaks, later they regurgitate on the edge of the nest only slightly macerated food which the chicks pick up for themselves. The young birds remain in the nest for seven or eight weeks, while acquiring a coat of feathers closely resembling but rather browner than that of the adults.

Central European herons generally spend the winter on the Mediterranean but have also been found in west and east Africa. During mild winters they may not even leave their nesting grounds. After the breeding season is over they can be seen standing completely motionless in shallow waters singly or in groups, waiting for their prey to come near, or they may sit hunched near the water, resting. In the autumn, they can be seen in the fields waiting beside the holes of field mice. The common heron is a native of Europe, ranging through central and southern Asia, and is found also in Africa including Madagascar.