536 MR. W. H. HUDSON ON PATAGONIAN BIRDS. [Apr. 1G, 



The plumage of the young birds is of a dusky grey, without any 

 white or black feathers or spots. When a year old they moult, and 

 acquire the spotted plumage of the adults, but do not attain the full 

 size till the third year. 



1. The Falcon*. 



This bird is met with in the thorny thickets on the high-terraced 

 tablelands on either side of the Rio Negro. It is a solitary bird, 

 and almost invariably found perched on the summit of one of the 

 little bushes or trees ; and amidst the uniform dull grey hue of the 

 vegetation, its broad, pure white bosom renders it conspicuous at a 

 great distance. It is a handsome bird, with an easy graceful flight, 

 and when looking out for prey sails far higher than Hawks usually 

 do. It preys much on the Tuco-tuco (i. e. Ctenomys brasiliensis), and 

 seems to find abundance of food ; for all the specimens I shot were 

 exceedingly fat. It builds its nest in the centre of a large bush, 

 and lays three white eggs. 



While looking out for specimens of this Hawk I met with 

 another species so remarkable in its structure and habits that 

 I cannot refrain from giving a short notice of it, though, to my 

 intense disappointment, I did not succeed in getting any speci- 

 mens of it. It is apparently smaller than Falco sparverius ; the 

 upper plumage grey, the wings and under plumage white ; the 

 tail is long ; the wings very blunt, and so short that when on the 

 wing the bird rushes through the air with great violence. They 

 are seen in pairs, sitting on the top of a bush, and at long intervals 

 through the day suddenly burst into a loud excited chorus of notes, 

 which resembles more the language of a Passerine bird than of a 

 Hawk. Whenever I approached one, it would utter a loud, long 

 cry of alarm, and go on repeating it till, before I was within shot, 

 it would fly off, and take up its position on a distant tree. I saw 

 about a dozen individuals, and followed them about several days, 

 but in vain. 



There is in the woods, on the margin of the Plata, a diminutive 

 Hawk very rarely seen, and called by the natives Rey de los Pajaros, 

 closely allied in size and form to the Patagonian bird, but differing 

 in colour and possessing a far easier flight. 



There are four Eagles found on the Rio Negro, but all doubtless 

 well known. I send you two Owlsf ; the Burrowing Owl is also 

 found along the Rio Negro. There are two Vultures, the Black and 

 the Red-headed Vulture. The Condor is also met with occasionally 



* The diurnal Accipitres of which specimens are sent by Mr. Hudson are 

 of nine species, namely : — 



1. Cathartes atratus (Bartr.). | 6. Harpyhaliaetus coronatus (Vieill.). 



2. Polyborus thanes (Mol.). | 7. Geranoaetusmelanoleucus (Vieill.). 



3. Milvago chimango (Vieill.). I 8. Buteo erythronotus (King). 



4. Hypotriorchis femoralis (Temm.). 9. Circus cinereus (Yieul.). 



5. Tinnuncidus sparverius (Linn.). I 



Unfortunately none of these are numbered 1 ; so that I am not able to say to 

 which, if any, of these species Mr. Hudson refers as " The Falcon.'' — P. L. IS. 

 t Bubo virginianus (Chn.) and Glaticidium nanum. — P. L. S. 



