NON-INDIGENOUS BRITISH BIRDS. 203 



during April and May. The favourite breeding grounds 

 of this Heron in Europe are swamps and the submerged 

 willow and alder forests on the banks of rivers which are 

 flooded every spring. This bird breeds abundantly in 

 various parts of the valley of the Danube in company 

 with other birds of the same family. It is gregarious 

 during the breeding season, also social. In most parts of 

 the world the Night Heron habitually nests in trees, 

 but in America it is said occasionally to breed on the 

 ground in marshes and amongst rice swamps. In 

 Europe low willow and alder trees are occupied, but in 

 India taller trees are selected, and Swinhoe mentions a 

 colony of this Heron which was established in some old 

 banyan trees in the courtyard of the great Honam 

 Temple at Canton. Bushes are however used in China 

 as well as in Europe, the same naturalist describing an 

 enormous colony of this bird in such places near another 

 temple, the nests being placed on every available branch, 

 sometimes only a few feet from the ground. The nest 

 is somewhat small, flat and shallow, and made of sticks. 

 The nests observed by Mr. Seebohm in the valley of the 

 Danube are described by him as having the sticks 

 arranged like radii from the centre, not in arcs round it. 

 When in swamps it would appear that reeds and stalks 

 of other aquatic vegetation are used instead of sticks. 

 When disturbed at their colony the birds become very 

 anxious, fluttering off their nests, and flying to and fro in 

 noisy alarm. 



Range of egg colouration and measurement : 

 The eggs of the Night Heron are from three to five in 

 number. They are chalky in texture, without polish, 

 and bluish-green in colour. Average measurement, 20 

 inches in length, by 1*4 inch in breadth. Incubation is 

 apparently performed by the female alone, but the 

 duration of the period is unknown. According to 



