318 STERCOEAEIIDJ.. 



2. Megalestris chilensis. 



Stercorarius antarcticus, Gay, Hist. Chile, Zool. i. p. 481 (1847). 

 Catarracta catarractes, Licht. Nomencl. Av. p. 99 (1854: Chile). 

 Lestris antarcticus, var. b. chilensis, Bp. Cvnsp. Av. ii. p. 207 (18-'37) 



{Mus. Berol.*, ex Am. Merid. " Rostro vix breviore quam iu 



Europseo, potius "raciliore quam robustiore "). 

 Lestris antarctica, Scl. i^ Salv. Ibis, 1869, p. 284 (Sta. Magdalena, 



Magellan Strs.). 

 Stercorarius cliilensis, Saunders, P. Z. S. 1876, p. .323, pi. xxiv. 



(revision Stercorariinae) ; id. op. cit. 1877, p. 800 (Magellan Strs.) ; 



id. Journ. Linn. Soc. xiv. p. 393 (1878: distribution); id. Voy. 



'Challenger,' ii. {Birds) p. 140 (1880: Magellan Strs): Sharpe, 



P. Z. S. 1881, p. 17 (Magellan Strs., 'Alert') ; Saunders, op. cit. 



1882, p. 627 (Callao IJay) ; Milne-Edw. Faune des Regions 



australes, ii. cliap. iv. p. 21, carte no. 1 (1882) ; Taczan. Orn. 



Perou, in. p. 458 ; J. R. H. 3IacFarl. Ibis, 1887, p. 206 (Callao 



Bay); Oiistalet, Miss. So. Cap Horn, vi. (Ois.) p. 172 (1891 J ; 



Berlepsch ^ Stolzm. P. Z. S. 1892, p. 400 (Peru). 



Adult in fresh plumage. Similar to the preceding species, but 

 much brighter in coloration. Forehead, crown, and occiput dark 

 brown ; hind neck brown, with narrow whitish streaks, and mottled 

 with chestnut; feathers of the mantle brown, with bright chestnut 

 central streaks ; upper tail-coverts chiefly chestnut, with brown 

 mottlings ; rectrices dark brown ; wings dark brown, with white 

 visible at the bases of the four outer pairs of quills, and more con- 

 spicuous on the underside ; chin, throat, under neck, breast, and 

 abdomen warm chestnut ; under wing, axillaries, and under tail- 

 coverts chiefly chestnut, mottled with brown : bill reddish black ; 

 tarsi black, often mottled with yellowish ; toes black. Total length 

 21 inches, culmen 2"3, wing 15-5, tail 6'5, tarsus 2-75, middle toe 

 with claw 2'8. 



The sexes appear to be alike in size, as well as in plumage. 



In less mature birds the chestnut colour is neither so pronounced 

 nor so extensive, but is always a strong characteristic of the species. 

 Just before the moult, however, the rufous colour becomes dull 

 and faded. 



Immature. Like the above, but with less ruddy colour on the 

 mantle. 



Young. Similar, but the feathers of the mantle are merely edged 

 with rufous and have no chestnut central streaks : " bill slate-colour ; 

 iris black ; tarsi aud toes slate, with a few lavender streaks " (*S'. F. 

 Rowland). 



Hah. Coasts of South America, from Rio de Janeiro down to the 

 Straits of Magellan aud up the Pacific side to Callao, Peru. Not 

 known to occur in the Falkland Islands, where the representative 

 species is M. antarctica ; but I think it possible that in the region 

 of that group and Eastern Patagonia a fusion may sometimes take 

 place. 



* Type examined. 



