FAMILY LARIDAE 457 



to my surprise as we came nearer these proved to be the sooty, 

 instead of the bridled tern that I had expected, an identification easily 

 evident since a number of the dark-plumaged immature individuals 

 were on the wing flying among the adults. The birds circled swiftly 

 in the strong wind, ranging out for some distance. On watching 

 we noted that occasionally a group came to the lee of the rocky 

 islets where the sea was a bit quieter, so that Captain Edgington cir- 

 cled in this area. Shooting was difficult because of the bucking of 

 the launch in the rough water, while the force of the wind made 

 the birds fly so wildly that only occasionally one came within 60 

 meters when a successful shot was due more to chance than to skill 

 in marksmanship. I secured 3 adults and 1 juvenile in due course 

 before the birds would no longer come near, so that we turned away 

 to head through the rough sea for a sheltered anchorage at Playa 

 Venado on the southern end of the Azuero Peninsula. It was my 

 estimate that there were approximately 100 pairs of the terns around 

 the larger of the two islets of the Frailes del Sur. Young birds, so 

 far as I could tell, were all on the wing, and the 3 adults taken, two 

 males and a female, were all past breeding. On the return journey 

 from the Veraguas coast 12 days later we passed the Frailes before 

 dawn so that I had no other opportunity for observations. 



This is the only specimen record to date for this race of the 

 sooty tern in Panamanian waters. Their breeding on Los Frailes 

 apparently is not based on the 12-month cycle of the calendar year, 

 since none were present when I visited these rocks at the end of 

 February 1957. 



Dennis R. Paulson, traveling on the yacht Argosy, A. Glassell 

 owner, recorded one seen resting on a bit of driftwood off Isla Pedro 

 Gonzalez, September 7, 1961. 



STERNA ALBIFRONS Pallas: Least Tern; Charrancito 



Sterna albifrons Pallas, in Vroeg, Cat. Adumbr., 1764, p. 6. (Maasland, Nether- 

 lands.) 



Smallest of the terns. 



Description. — Length 210 to 230 mm. Adult, breeding dress, fore- 

 head, sides of crown back to level of eyes, and entire under surface 

 white ; a narrow line from lores around eye, crown, and upper hind- 

 neck black; rest of upper surface, including tail, light neutral gray; 

 outer webs of outermost primaries slate black, with inner webs 

 white. 



