AVES — FALCONID.E. 577 



ing. The M. albogularis is remarkable from the confined locality which 

 it appears to frequent. A few pair were seen during the ascent of the 

 river Santa Cruz (Lat. 50° S.) to the Cordillera; but not one individual 

 was observed in any other part of Patagonia. They appeared to me to 

 resemble, in their gait and manner of flight, the P. Brasilieusis ; but they 

 were rather wilder. They lived in pairs, and generally were near the 

 river. One day I observed a couple standing with the Carranchas and 

 M. pezoponts, at a short distance from the carcass of a guanaco, on which 

 the condors had commenced an attack. These peculiarities of habit are 

 described by M. D'Orbigny in almost the same words, as occurring with 

 P. montanus ; both birds frequent desert countries; the P. montaints, 

 however, haunts the great mountains of Bolivia, and this species, the 

 open plains of Patagonia. 



"In the valleys north of 30° in Chile, I saw several pair, either of this 

 species or of the P. moutaims of D'Orbigny (if, as is probable, they are 

 different) or of some third kind. From the circumstance of its not ex- 

 tending (as I believe) so far south even as the valley of Coquimbo, it is 

 extremely improbable that it should be the M. albogularis — an inhabitant 

 of a plain country twenty degrees further south. On the other hand, the 

 P. nionfanns lives at a great elevation on the mountains of Upper Peru ; 

 and therefore it is probable that it might be found in a higher latitude, 

 but at a less elevation. M. D'Orbigny says, 'Elle aime les terrains sees 

 et depourvus de grands vegetaux, qui lui seraient inutiles; car il nous est 

 prouve qu'elle ne se perche pas sur les branches.' In another part he adds, 

 'Elle descend cependent quelquefois jusque pres de la mer, sur la c6te 

 du Peru, mais ce n'est que pour peu de temps, et peut-etre afin d'y chercher 

 momentanement une nourriture qui lui manque dans son sejour habituel ; 

 peut-Stre aussi la nature du sol I'y attire-t-elle ; car elle y trouve les ter- 

 rains arides qui lui sont propres.'^ This is so entirely the character of 

 the northern part of Chile, that it appears to me extremely probable, that 

 the P. montanus, which inhabit the great mountains of Bolivia, descend 

 in northern Chile, to near the shores of the Pacific ; but that further south, 

 and on the opposite side of the Cordillera, it is replaced by an allied 

 species — the M. albogularis of Santa Cruz." (Darwin, Voy. Beagle, 

 Birds, pp. 19-21. 1 84 1.) 



'Voyage dans rAmerique Meridionale, Partie, Oiseaux, p. 52. 



