1 920. J Cape San Anlonio, Buenos Ayres. 81 



417. Lams maculipennis Liclit. Spot-winged Gull. 



Iris brown or dark brown, as distinguished from the 

 yellow or pale straw-colour of Larus cirrhocephalus. 



Mr. Hudson has given such a full and detailed account 

 of the habits of this dark-hooded Gull as to leave me little 

 to add. Sometimes the species is found alone, but more 

 generally it is associated with the Grey-capped Gull (L. 

 cirrhocephalus Vieill.). From tlie nnmerous entries in my 

 journal I can deduct no general principle which would seem 

 to explain these circumstances. 



Once I saw an individual seize and carry off from its nest 

 a young waterhen, a procedure which struck me as out of 

 place and liighly reprehensible, as I supposed the species to 

 be non-predatory. The other extreme is conveyed in the 

 following curious note, dated 9th November, 1899: — 

 ''Observed a flock of about fifty Gulls (all of which were 

 L. maculipennis) assemhled in the open camp around an 

 ants'-nest (of the large black kind), the denizens of which 

 were in the winged state. The Gulls either alighted on the 

 ground in their pursuit, or hawked them in the air." 



The Spot-wiugcd Gull nests with us between the end of 

 October and the beginning of. January, in company with 

 Trudeau^s Tern. As mentioned when writing of the latter 

 species, eighteen years had passed before I discovered my 

 first colony of Terns (in 1890), and consequently that of the 

 Gulls. Since then only some four or five others have come 

 under my notice, and these at long intervals. I have never 

 known the birds revert to a former site. The situation has 

 been described in the notice of the Tern ; not necessarily in 

 an out-of-the-way place or fastness, bat often in a noticeable 

 locality. Open, and comparatively shallow, water is pre- 

 ferred, sometimes on the verge of a rush-bed. None of the 

 colonies exceeded a hundred pairs, some being only half 

 that number. The nests might be closely placed or widely 

 scattered, according to the nature of the site. As a rule 

 they are mere floating piles of wet water-weeds, in beds of 

 the same ; but I liave known them built of dry junco-stems, 

 slight and shallow, and lined with a little dry water-grass. 



SER. XI. VOL. II. q. 



