116 TYRANNID^E. 



p. 603 (Buenos Ayres) ; Doring, Exp. al Rio Negro, Zool p. 42 (11. Colo- 

 rado) ; Barrows, Bull. Nutt. Orn. CL vol. viii. p. 138 (Eutrerios). Xolmis 

 variegata, Darw. Zool Voy. Beagle, iii. p. 54 (Sauta Fe). 



Description. Above cinereous ; rounded summit of head black, broad front 

 and band encircling the black of the head white ; wings blackish, upper coverts 

 cinereous, edgings of middle and greater coverts and of outer secondaries 

 whitish ; tail blackish, margins of outer webs of external tail-feathers white : 

 beneath white ; under wing-coverts and a large portion of the inner webs of the 

 remiges, except of the two outer primaries, white ; bill and feet black : whole 

 length 7-8 inches, wing 4-6, tail 3-1. Female similar. 



Hob. Argentine Republic, Uruguay, and Paraguay. 



In this species the sexes are alike. The crown is black and com- 

 posed of loose feathers ; the forehead, and a broad line over the eye 

 which extends nearly round the head, also all the under plumage, pure 

 white ; neck and back clear grey ; quills black. 



This Tyrant is a solitary bird, though often many individuals are found 

 within call of each other, and they sometimes even unite in a loose flock. 

 It is found throughout the Argentine country, ranging south to the 

 Rio Negro, in Patagonia, but abounds most on the Buenos-Ayrean 

 pampas, where it performs a partial migration. Most of the Tanwptera 

 seek their food by preference on the bare level ground, or where the 

 vegetation is most scanty. This species varies somewhat in habits, and 

 seldom runs on the ground, and chiefly inhabits the desert plains, 

 where the large grasses flourish. On one occasion when I was with 

 an expedition on the pampas for several weeks, every day a number of 

 these birds would gather and follow us ; perched here and there on 

 the tall grasses with their bosoms toward us, they often looked at a 

 distance like large white flowers. Old gauchos have told me that fifty 

 years ago they were abundant all over the pampas, but have disap- 

 peared wherever the giant grasses have been eaten down, and have given 

 place to a different vegetation. 



Their note is a long, low whistle, the usual language of the Tanio- 

 ptera ; but in this species it is very like a human whistle, on account of 

 which the bird is named Boyero (ox-driver) on tbe pampas. One 

 severe winter great numbers of them appeared in the neighbourhood of 

 Buenos Ayres, and it was amusing to see the dogs thrown into a great 

 state of excitement by the low whistling notes heard perpetually from 

 all sides. Every few moments they would start up and stare about 

 them to ascertain where tbe deceptive call came from, and in spite of 

 many disappointments they would occasionally all rush away, loudly 

 barking, into the plantation, convinced that some person there was 

 whistling to call them. 



The Black-Crown makes a somewhat shallow nest in a bush or large 



