Larus occidentalls . Western gull. Seen 

 wealth-ward from San Diego to a distance 

 of 90 miles off the Gulf of Tehuantepec. 

 Along the shores of Baja California this 

 species appeared in alternate with bands 

 of the California gull. 



Larus calif ornicus . California gull. 

 Encountered only along the coast of Baja 

 California. Off the broad entrance to the 

 Gulf of California, Dec. 10-12, we met 

 many immature examples which behaved like 

 veteran pensioners of ships and were 

 content to wait hours for jettisoned 

 garbage. At one time I counted 250 around 

 Stranger . White, adult California gulls 

 were mostly seen farther northward. 



Larus atricilla . Laughing gull. Common in 

 the Gulf of Panama. First seen in 

 considerable numbers immediately after we 

 had rounded Cape Mala on Nov. 26. On Dec. 1 

 several followed us out to the high sea for 

 about 100 miles S of Balboa. This gull was 

 also common in Gatun Lake, Canal Zone, 

 mingling with small flocks of black terns. 



The first specimen of the laughing gull, 

 however, was collected far off the coast 

 of Baja California, at 22°57' N, 113°3^' W, 

 on Nov. 10. A second was taken at 

 05°59' N, 79°W5' W, Dec. 1. 



Larus pipixcan . Franklin's gull. Adults 

 still wearing full summer plumage were seen 

 off western Panama on Nov. 25. The two 

 collected were both young birds, taken at 

 sea on Nov. 23 at 09°la' N, Q9°hh' W. The 

 position is in the "Dome" area, about 2*10 

 miles W of Costa Rica. The longitude, which 

 is far to westward of South America, passes 

 through the Galapagos Islands, to which 

 Franklin's gull is a regular winter visitor. 



Larus heermanni . Heermann's gull. Observed 

 between Cedros Island, Baja California, and 

 San Diego, Dec. 15-l6. 



Xema sabini . Sabine's gull. Seen 

 pccasionally and usually at long range, 

 southward to Panama. A female was collected 

 on Dec. 12 at 23°31' N, 111°22' W. The 

 position is W and a little N of Cape San Lucas. 



Sterna hirundo. Common tern. Small terns 

 were seen on many dates, but the only certain 

 identification is based upon a female of this 

 species collected on Nov. 15 at l 1 v°17' N, 

 96°3l4.' W, off the Gulf of Tehuantepec. 



Thalasseus maxlmus . Royal tern. Common in 

 the Gulf of Panama, Dec. 26-30. 



Chlidonias niger . Black tern. First observed 

 off the Gulf of Dulce, western Panama, 

 Nov. 25. Common in the Gulf of Panama and on 

 Gatun Lake, where it mingled with laughing 

 gulls . 



The black tern in its winter range clings 

 closely to tropical coasts and flotsam-filled 

 waters. It never dives and it rests mostly 

 on floating vegetation. Therefore it is 

 always most abundant where rivers flow to the 

 ocean through forested areas . It is very 

 rarely found out of sight of land. 



Anous stolidus. Brown noddy. An adult 

 female with slightly enlarged ovaries was 

 collected on Manuelita Islet, off the northern 

 point of Cocos Island, on Dec. 3. On 

 Dec. 8 at 1V37' N, 100°09' W, about 190 miles 

 south of Acapulco, I saw a small flock of 

 this species. 



Megalopterus mlnutus . Black noddy. Black 

 noddies came aboard Stranger early in the 

 morning of Nov. 23. Later in the same day 

 an adult male was collected at 09° kl 1 N, 

 Qg'kk' W, which is in the "Dome" area, about 

 240 miles W of Costa Rica. 



On Dec . 3 several examples were seen flying 

 in and out of a sea cave on Manuelita or 

 Nuez Islet, Cocos Island. 



Land Birds. A considerable number of land 

 birds alighted on Stranger in various parts of 

 the cruise . Some of them could be only 

 approximately identified: 



Speotyto cunicularia . Burrowing owl. Nov. 13, 

 more than 1+0 miles off Petacalco Bay, Mexico . 



Large flycatcher. Nov. 25, W of Coiba Island, 

 Panama. 



- 109 



