BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 137 



subsequent to that date. As Dr. L. Stejneger has pointed out in 

 a dissenting opinion accompanying this action of the International 

 Committee the names given in the edition for 1762 fulfill all of 

 the conditions imposed by the code to make them eligible. 



STERNA TRUDEAUI Audubon 



Sterna trudeaui Audubon, J. J., Birds of America (folio), vol. 4, 1S38, 

 no. 82, pi. 409, fig. 2. (Great Egg Harbor, N. J.) 



Trudeau's tern was locally common in eastern and southern Buenos 

 Aires and near the coast in eastern Uruguay, but was not recorded 

 elsewhere. It was first noted on October 21, 1920, near Dolores in 

 eastern Buenos Aires, where I recorded a dozen or more in pairs 

 that flew back and forth along a drainage canal cut through a 

 marsh. As two passed near at hand I killed the female with a 

 shot from my collecting pistol. Near Lavalle the species was fairly 

 common from October 25 to November 15, and a second female was 

 secured on November 4. One shot October 31 was preserved as a 

 skeleton. Near Carrasco, east of Montevideo, Uruguay, one was 

 seen January 9, 1921, and on January 16 the birds were common. 

 The skull of a dead bird that had washed ashore was secured on 

 the latter date. One was observed on the coast at La Paloma below 

 Eocha, Uruguay, on January 23, and about 20 were recorded Janu- 

 ary 31 at the Laguna Castillos below San Vicente. One was se- 

 cured there in a helpless condition from alkali poisoning. Near 

 Guamini, Buenos Aires, from March 3 to 8 the species was fairly 

 common on the borders of the large lagoons. It was not unusual 

 to find 100 or more gathered in company with gulls. This point 

 was the farthest inland at which I noted the species, as elsewhere 

 it was foimd only along the coast or in level marshy areas near tide 

 water. 



Trudeau's tern in flight and general actions is similar to other 

 smooth-headed terns. As the birds beat back and forth with zigzag 

 flight along shallow channels they darted down at intervals to secure 

 small fish that appeared in the water within striking distance. 

 When they were not feeding they gathered in close flocks to rest 

 on some sandy beach or point near water. Below Cape San Antonio 

 parasitic and long-tailed jaegers harried them and made them 

 disgorge. Once or twice I noted hooded gulls in similar attempts, 

 but in each case the tern with seeming ease eluded its less agile 

 pursuer. 



The call notes of Trudeau's tern are sharp and explosive and 

 suggest in many ways the sounds emitted by Forster's tern, a species 

 that the present one suggests strongly in life. A usual call was a 

 sharp tik tik tik, changed when birds became angry or excited to 

 a drawn out keh-h-h. As birds in full plumage approach across 



