EGRETS, HERONS, ETC. 171 



of space to spare for their accommodation. Not 

 many years before I left India, a wooded islet in 

 the Zoological Garden at Alipur was invaded by a 

 colony as a roosting and nesting site, and, although 

 the event was at first welcomed as adding a new 

 and attractive feature to the place, there can be no 

 question that it was in the end most destructive 

 to the beauty and amenity of its immediate sur- 

 roundings. During the first season only a limited 

 number of birds established themselves, but year 

 by year more and more made their appearance, 

 and within a short time all the trees were thickly 

 tenanted. The aspect presented by the island 

 towards the end of each breeding season, with all 

 the trees bending beneath the weight of the nests 

 and thronged with birds drowsing away the sunlit 

 hours, was most remarkable. Even more curious was 

 the sight that presented itself in the evening as the 

 colony gradually roused up for the night (Plate XI.). 

 As the sun went down drowsy voices began to be 

 heard, at first at wide intervals, and then more and 

 more frequently, until the air was full of the sound. 

 At the same time signs of unrest began to appear; 

 birds began to shift about from place to place or 

 make short flights out over the water ; and as the 

 dusk deepened they set out, at first in pairs and 

 small companies and then in a ceaseless stream that 

 lasted until it was hardly distinguishable in the 

 growing gloom save by the multitudinous cries of 



