BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 131 



tarsus itself was black. One specimen taken had lost the distal por- 

 tion of one foot in some ancient injury. 



From November 4 to 7 long-tailed jaegers, acompanied by a few 

 parasitic jaegers, were in migration southward along the broad sand 

 beach extending southward from Cape San Antonio. On the after- 

 noon of November 4 three came drifting slowly down to leave two 

 of their number lying on the sand, while the third, more wary, kept 

 out of range and continued southward. 



During the two days following a tremendous gale of wind and 

 rain made field work useless, so that I was confined to short excur- 

 sions about camp. Occasional jaegers passed, keeping low down 

 behind the shelter of the dunes, sweeping by at high speed, driven 

 by the high velocity of a quartering wind. With fairer weather on 

 November 7 the birds increased and were in sight constantly, all in 

 silent passage toward some winter range in the south. The number 

 that I actually saw during the period of my observations must have 

 ranged between 1,200 and 1,500, while the total number of indi- 

 viduals that passed was far in excess of this. 



The birds traveled alone or in little groups of three or four, some 

 wary and others very tame. They drifted along, frequently scaling 

 for long distances or occasionally flapping their wings, never more 

 than 50 feet in the air, often only a few feet above the sand. At 

 intervals one dropped lightly to the beach near the water mark to 

 pick up a few beetles that had drifted ashore after the storm and 

 then remained to rest for a few minutes. Others more energetic 

 harried the Trudeau's terns with agile wing strokes until they dis- 

 gorged their prey of fish on the sand, when the jaeger stooped easily 

 to pick it up and then continued its flight. Their steady southward 

 movement without pause to circle about or return was most 

 impressive. 



Family LARIDAE 



LARUS DOMINICANUS Lichtenstein 



Larus dominicanus Lichtenstein, Verz. Doubl. Zool. Mus. Berlin, 1823, 

 p. 82. (Coast of Brazil.) 



In a recent paper Fleming" has named a form of this gull from 

 the South Shetland Islands on basis of lighter color. Mathews and 

 Iredale ^^ list the black-backed gull of New Zealand as Larus domint 

 amus antipodus (Bruch) without comment as to the differences con- 

 sidered as a basis for' this subspecific designation. After study of 

 an insufficient series of dominicanus that includes specimens from 

 both Atlantic and Pacific coasts of South America, New Zealand, 



15 Larus dominicanus austrinus Fleming, Proc. Biol. Soc. Washington, vol. 37, Dec. 

 29, 1924, p. 139. (Deception Island, South Shetland Islands.) 

 " Ibis, 1913, p. 248. 



