444 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ISO 



the breeding plumage begins in late February and continues through 

 the middle of March. By the end of March birds that display the 

 black head of the summer dress are common. Flocks in full plumage 

 evidently are in northward flight by early April. Though there is 

 great reduction in their number at this time, scores remain in 

 Panama through the months of northern summer. Scattered birds, 

 all in nonbreeding plumage, may be found in their usual haunts 

 through this period, with flocks congregated in favorable localities 

 where food is attractive. As an example, on May 11, 1953, I ob- 

 served 50 or more widely scattered high in air over Albrook Field, 

 evidently hawking for flying insects, probably termites. 



The greatest concentrations during the winter months are in the 

 Gulf of Panama, where they range down to Punta Mala and shift 

 about with changes in wind and tide. Many join the pelicans, 

 cormorants, and frigatebirds as they feed on the great schools of 

 sardinelike fishes. When these appear gulls may be observed in 

 flight toward them from considerable distances. After feeding small 

 groups may raft in fairly close formation, but it is more common to 

 find them spread singly, or 2 or 3 together, over wide spaces of the 

 sea. As passing launches disturb them, or as the waves increase, they 

 rise and straggle off, flying into the wind. Such groups fly regularly 

 and easily if disturbed on the darkest nights, seemingly without being 

 troubled by the lack of light. Flocks that may number 1500 to 2000 

 birds appear regularly in the Bay of Panama from the entrance of 

 the Canal around to Panama Vie jo. 



Laughing gulls cross the Isthmus through Gatun Lake and also 

 appear at times on such smaller bodies as the Miraflores lakes and 

 water impoundments in the old banana farms near Changuinola. 

 They come also with regularity over the wide reaches of the Chagres 

 above Gamboa toward Madden Dam, but the lake above does not 

 seem attractive, probably through its lack of easily accessible food. 

 Once in early January I saw 4 walking over short cut grass opposite 

 the old Balboa railroad station, but this appears to be unusual. 



In launch travel during March, when anchored in some protected 

 bay, at sunrise I have seen flocks of up to 200 or more swing in 

 suddenly from the sea, turn and gyrate wildly for several minutes in 

 wind currents high in air, and then disappear. On one trip in the 

 little steamer Pirre, while crossing the Gulf of San Miguel toward 

 the mouth of the Tuira, an immature gull with a band on one leg 

 appeared among the following flock and came repeatedly close at 

 hand. The numerous records in Panama of birds banded between 



