156 BRITAIN'S BIRDS AND THEIR NESTS. 



sometimes a ledge on some ivy-clad crag, or on an old ruin, 

 forms the site. Irish heronries are naturally often in the 

 less usual situations. 



The nest is usually a large saucer-like platform of boughs, 

 and so on, lined with twigs or herbage. It is often added to 

 year after year, and may in the end measure many feet in 

 diameter. Naturally, however, the nest varies considerably 

 in type with the nature of its situation and the available 

 materials. 



The Heron is an early nester, and may usually be found 

 about the heronry before January is out. In fact, the eggs 

 are frequently laid in the first half of Febiuaiy. Four is 

 the most frequent number, but there may be three or five. 

 They are of a delicate, unspotted, greenish blue. Rather 

 less than four weeks' incubation is required before the young 

 are hatched. These are nidicolous, being at first blind, 

 featherless, and utterly helpless. In May they leave the 

 nest, and their parents very frequently rear a second brood 

 the same summer. 



The Heron, although itself a predaceous species, is liable 

 to much persecution by other birds. This occiu's chiefly 

 when it is on the wing, when its slowness in manoeuvring 

 makes it almost defenceless. Thus it is often mobbed by 

 Terns or other birds over whose colonies it unwarily passes 

 — this perhaps from knowledge of its fondness for young 

 birds ; and when it appears in the open it is persistently 

 chivied by the Rooks, side by side with which it often 

 nests ! A pair of raiding ravens are said to be able to 

 put a whole colony to flight. Of even the smallest Birds- 

 of-Prey, speaking now in the strict sense, the Heron is 

 always in great dread, and it attempts to rise in circles 

 above its aggressor if it be too far from a wood to make 

 a dash for shelter. This helped to make it a favourite 

 quarry of the old falconers, as indeed it still remains of 



