HERONS AND EGRETS 239 



River near Waterval North in the Pretoria District, where 

 it roosted nightly in flocks on the drooping branches of 

 some trees growing on the bank ; at sunset the birds could 

 be seen flying in long lines from the veld, where they had 

 been freeing the cattle of their ticks (often the birds' main 

 article of food). 



Harold Fry discovered this Egret nesting on the Vaal 

 River, near Parys, Orange Free State, in November, and 

 Roberts, near Balmoral, in December. The eggs are pale 

 blue in colour. 



The Green-Backed Heron (Butorides atrica'pilla) has the 

 top of the head, back and tail glossy dark green ; below 

 ashy grey except for a streak of rufous down the centre of 

 the breast ; chin, centre of throat and front of neck white. 

 Length, about 16 inches. 



It is found in the east of the Cape Province, the lower- 

 lying portions of Natal, ranging northwards. There was 

 a pair of these pretty little Herons in the National Zoo- 

 logical Gardens caught when in immature plumage at 

 Six-mile Spruit, near Pretoria. 



The Night Heron (Nycticorax nycticorax) has the crown 

 and back greenish-black ; neck and the best part of the 

 wing dove-grejr ; rest of plumage snowy white, including 

 two long plumes springing from the back of the head. 

 Length, 22 inches. 



It is widely distributed throughout South Africa. We 

 found it common on the Valsch River at Kroonstad in 

 April, 1906 ; there was quite a large proportion in the 

 immature grey dress. 



It is somewhat nocturnal in habits, spending the greater 

 part of the day amongst the thick trees and reed beds 

 bordering the river. The nest is a saucer-like platform of 

 sticks, and the eggs are pale greeny-blue. 



