158 BIRDS OF LA PLATA 
More than that, the male, while unfriendly towards 
all other species, appears to cherish a special anti- 
pathy against the red bird; and when one comes 
near him never fails to pursue it with the greatest 
violence from the neighbourhood. He is also 
strictly solitary, but the red birds frequently unite 
in small parties, especially in autumn, when I have 
often seen as many as a dozen together. Evidently 
they have a more social temper than their black mates. 
The native boys have discovered a strange weak- 
ness in the Silverbill, When the bird is running 
about seeking food on the ground, the boy approaches 
it and hurls a stick or clod and at the same time 
rushes at it, whereupon the bird as if paralysed 
remains motionless, and may be taken by the hand. 
Altogether the Silverbill has been a puzzle in 
the past, and it would appear, from some obser- 
vations made by Mr. Barrows, that we have not 
yet got to the end of all the curious points in its 
habits. Without doubt it is migratory. Its range 
extends from Paraguay to Patagonia, where it is not 
common. In Paraguay and the hotter parts of the 
Argentine country it is probably stationary; in 
Buenos Ayres, where it is most abundant, many 
individuals remain all the year in sheltered places, 
and the migration appears to become more definite 
the further south we get. Mr. Barrows travelled 
south across the pampas in the autumn, and says: 
“ The species was met with at all points visited, but 
south of the Azul not a single male in the black 
plumage was seen, though the brown birds (pre- 
