COMMON HERON. 249 



tations, and groves of trees on islands, but in localities 

 where suitable trees cannot be found, a ledge of a cliff, a 

 ruin, or even the ground is chosen. The presence of 

 water is not essential to a heronry. This bird breeds in 

 societies like Rooks, and as it probably pairs for life, 

 yearly returns to one favourite spot to breed. Some of 

 our British heronries have been in use from time imme- 

 morial. The nest of this species is built in a great 

 variety of situations, on trees of all kinds, especially firs 

 and larches, on ivy-clad ruins, on the ledges of crags and 

 cliffs, and amongst heather on the hill-sides. In some 

 cases a heronry will be established in or near a rookery. 

 The nest is usually a bulky flat platform of sticks, 

 generally at some distance from the trunk on a broad 

 horizontal branch, less frequently on the top of a tree, or 

 in a wide fork close to the stem. The finer sticks are used 

 for the interior, which is sometimes further embellished 

 with turf and moss. The nests vary a good deal in size, 

 some of them being very large, and evidently the accu- 

 mulation of years, and all are more or less whitewashed 

 Avith droppings. Some trees contain but one nest, others 

 two or three, according to the amount of accommodation 

 offered, or the caprice of the birds. When the colony is 

 invaded the big gray birds flutter from their nests, their 

 wings crashing against the branches, and all is soon in 

 silent commotion. As long as the intrusion lasts the 

 birds continue to soar above their nests, now high, now 

 low ; every now and then a bird dropping on to its 

 home as soon as the intruder is a safe distance away. 



Range of egg colouration and measurement: 

 The eggs of the Heron are from three to five in number. 

 They are greenish-blue in colour, more or less elliptical 

 in shape, without polish, chalky, and rough in texture. 

 They also vary a good deal in tint, some being much 

 brighter and bluer than others. Averagfe measurement, 



