260 LETTER FROM MR. W. H. HUDSON. [Mar. 21, 



plumage as the females. Soon they become mottled with black, and 

 before leaving us have only a few dark grey speck3 to distinguish 

 them from the adults. They are quarrelsome and lively, incessantly 

 hopping and flitting about the little spot of bare earth they attach 

 themselves to. This may be the barren ground surrounding a 

 Vizcacha village, a sheep-fold, or the dry trodden place where a herd 

 of Cows is made to stand at night. They are also fond of muddy 

 low grounds, when the grass is closely cropped. Occasionally one 

 is seen to perch on a reed or thistle-bush ; but they have so great an 

 antipathy to trees that they will scarcely even alight on the ground 

 near one. This characteristic of the true pampas birds is scarcely 

 stronger in the Anthus correndera than in the present species. 



" The Cinclodes fuscus is also a lively bird, and quick in its mo- 

 tions on the ground, but when perched on trees sits motionless in 

 one posture. They are quarrelsome and sportive, and when pursuing 

 each other utter a trilling excited cry. Occasionally on a warm day 

 they attempt to sing, darting up from the ground as they utter their 

 notes ; but their voice is as destitute of melody as their plumage is 

 of brilliant hues. 



" Neither of the foregoing species is strictly gregarious ; yet 

 several individuals are usually seen near together, and the Osquitas 

 are sometimes met with on the plain or flying in small and scattered 

 flocks. 



" The Tcenioptera variegata appears on the eve of winter, and is 

 subsequently found thinly and widely distributed over the plains. 

 Their migration probably extends several degrees further north ; for 

 they are most numerous when they first appear, and at that time 

 seem, both when running on the ground and when flying, always 

 to be advancing north. 



" Two Hawks are amongst our winter visitors — the Hypotriorchis 

 femoralis and Tinnunculus sparverius. They come and go about 

 the same time, are not common, but widely distributed, and resemble 

 each other in their manner of flight, the habit of perching on a dry 

 limb or post, and the haunting some favourite hedge or orchard 

 throughout the winter. A person from Patagonia has informed me 

 that the smaller Hawk is very common in summer in the neighbour- 

 hood of the settlement of the Rio Negro, and breeds there, building 

 its nest in trees. 



" There are two Gulls amongst our winter immigrants — a large 

 black-winged Gull, and a dusky grey Gull with a black bill. These 

 birds probably breed on the shores of the Atlantic ; in winter they 

 are found pretty widely distributed over the pampas. Wherever 

 the hide is stripped from a dead Horse or Cow they appear, Vulture- 

 like, to feed on the flesh, wandering away again when it is finished. 

 These birds appear to possess no regular migration : the grey spe- 

 cies is always very rare ; and the black-winged Gull is much more 

 numerous in some seasons than in others. 



" There are also two Geese, the largest of which is the Butarda 

 (Bemicla magellanica). There is a great difference between the 



