HEN HARRIER. 209 



everywhere it appears to be getting rarer. In Ireland 

 it still breeds in some of the mountain districts. 



Breeding habits : The Hen Harrier is for the 

 most part a summer visitor to our islands, arriving in 

 April and May, although a few individuals remain in 

 them throughout the winter. The haunts of this rare 

 and conspicuous bird are wild moorlands, and the heath 

 and gorse-clothed sides of mountains. It shows little 

 or no preference for marshy ground, choosing the dry 

 parts of the moors and heaths, and at much higher 

 elevations than those selected by the preceding species. 

 It is not at all social, each pair keeping to a particular 

 area and to themselves. The nest of this Harrier is 

 invariably placed upon the ground, often amongst very 

 tall heather, but sometimes in a more bare and open 

 situation in a little clearing amongst surrounding vege- 

 tation. In this country the nest is usually merely a 

 hollow lined with a little dry grass and with a few twigs 

 round the margin, but in some other instances it is a 

 much larger structure a foot or more high, yet made 

 of similar materials. As a rule the smaller nests are 

 made in the barer situations. The bird does not sit very 

 closely, and its actions at the nest are similar to those of 

 the preceding species. 



Range of egg colouration and measurement : 

 The eggs of the Hen Harrier are from four to six in 

 number, five being the usual clutch. They are bluish- 

 white, almost the colour of skimmed milk, and very 

 exceptionally have a few pale rusty markings. Average 

 measurement, i*8 inch in length, by i'4 inch in breadth. 

 Incubation, performed by the female, lasts from twenty- 

 one to twenty-four days. 



Diagnostic characters : The eggs of the Hen 

 Harrier may usually be distinguished by their size — in- 

 termediate between that of the former and the following 



p 



