MANY-COLOURED TYRANT 175 
yards, when it again drops down. Yet it is strictly 
migratory. Darwin met with it at Maldonado in the 
month of June, and therefore concluded that it does 
not migrate ; but he mentions that it was very rare. 
I have also occasionally seen one in winter on the 
pampas, but many migratory species leave a few 
stragglers behind in the same way. At the end of 
September they suddenly appear all over the pampas, 
in every swamp and stream where there are beds of 
rushes; for in such situations only is the bird 
found: and this migration extends far into Pata- 
gonia. They are always seen in pairs amongst the 
dense rushes, where they perch on the smooth stems, 
not near the summit, but close down to the surface 
of the water, and perpetually hop from stem to stem, 
deftly picking up small insects from the surface of 
the water. They also occasionally leave the rushes 
and search for insects in the grass and herbage along 
the border. They are very inquisitive, and if a person 
approach the rush-bed, they immediately come out 
of their concealment, both birds uttering their 
singular notes—a silvery, modulated sound, not 
meant for a song apparently, and yet I do not know 
any sweeter, purer sound in nature than this. All 
through the close-growing dark rushes the pretty 
little melodists may be heard calling to each other 
in their delicate gurgling notes. 
The nest is a marvel of skill and beauty. Asa rule 
it is attached to a single polished rush, two or three 
feet above the water and about the middle of the 
stem. It is cup-shaped inside, and about four inches 
