19 1 8.] Caue San Antonio, Buenos Ay res, 381 



27. Progne tapera (Liuu.). Tree-Martiu. 



Again, I have few further notes to add to my former 

 observations on this species, beyond coafinningMr. Hudson's 

 remarks regarding its autumnal departure. I have occa- 

 sionally, but not often, seen it congregated on a tree or 

 trees in the wood, to the number of fifteen or twenty, and 

 even iu one instance some thirty, adults and young, in the 

 month between 13 February and 10 March. But this, 

 undoubtedly, is unusual. 



One characteristic of P. tapera which has been overlooked 

 by Hudson, Grant, and, hitherto, myself, is its untiring 

 pugnacity. How often have I seen the victim — perhaps 

 even the Tree Teal {Querquedula fiavirostris) — winding 

 silently and desperately through the trees, whilst the 

 equally mute Tree-Martin sped closely after it, curving 

 with every swerve of the other like a baleful shadow. 

 My carpenter, alluding to this habit, told me how it 

 bullied his Pigeons, getting behind and below them and 

 striking up at the root of the tail, sometimes knocking 

 feathers out. His birds ^vere much afraid of these attacks, 

 and would promptly drop down into his yard when struck. 



28. Petrochelidon pyrrhonota (Vieill.). Red-backed Rock- 

 Mariiii. 



Mr. Grant first chronicled this bird as a passing migrant 

 on 2 March, 1909, and again on 23 February, 1910. Another 

 correspondent further wrote me on 29 March, 1910 : — 

 " P, pyrrhonota is going across now. I saw a flock of from 

 twenty to thirty this morning." It would seem not to make 

 any stay in our district. 



29. Tachycineta leucorrhoa (Vieill.). White - rumped 

 Swallow. 



Mr. Hudson has written so fully on this species that he 

 has left little for me to add. For a migrant, it is difficult 

 to specify its arrival and departure. As he says, there is an 

 invariable re-appearance throughout the winter on sunny 

 days, however cold. For example, June 1875 happened to 



