Music and Dancing in Nature. 273 
bird, the first bird, on the appearance of its mate 
flying to join it, begins to emit loud, measured 
notes, and sometimes a continuous trill, somewhat 
metallic in sound; but immediately on the other 
bird striking in this introductory passage is changed 
to triplets, strongly accented on the first note, in a 
tempo vivace; while the second bird utters loud 
single notes in the same time. While thus singing 
they stand facing each other, necks outstretched 
and tails expanded, the wings of the first bird 
vibrating rapidly to the rapid utterance, while those 
of the second bird beat measured time. The finale 
consists of three or four notes, uttered by the 
second bird alone, strong and clear, in an ascending 
scale, the last very piercing. 
In the melodists proper the displays, in a majority 
of cases, are exclusively vocal, the singer sitting still 
on his perch. In the Troupials, a family of starling- 
hike birds numbering about one hundred and forty 
species, there are many that accompany singing 
with pretty or grotesque antics. The male scream- 
ing cow-bird of La Plata, when perched, emits a 
hollow-sounding internal note that swells at the end 
into a sharp metallic ring, almost bell-like: this is 
uttered with wings and tail spread and depressed, 
the whole plumage being puffed out as in a strutting 
turkey-cock, while the bird hops briskly up and 
down on its perch as if dancing. The bell-like note 
of the male is followed by an impetuous scream 
from the female, and the dance ends. Another 
species, the common Argentine cow-bird of La 
Plata, when courting puffs out his glossy rich violet 
plumage, and, with wings vibrating, emits a succes- 
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