86 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



This booby, the boldest and most inquisitive of the five 

 species met with on the Expedition, was found commonly at 

 Culpepper, Tower, and Wenman islands. One example was 

 observed close to Gardner-near-Charles on October 3, 1905, 

 and one near South Abingdon on September 22, 1906. On 

 September 14, 1906, I noted two about twenty miles south of 

 Tower Island. None were encountered at Hood Island, 

 where Messrs. Snodgrass and Heller found them nesting in 

 May.^ One in the dark phase was seen south of the archi- 

 pelago on June 15, in latitude 2° 17' South, longitude 90° 58' 

 West. Most of the birds seen in the Galapagos Islands were 

 in the dark phase, although a number in the light phase were 

 noted at Culpepper, Tower, and Wenman islands — chiefly at 

 Culpepper. Birds in all sorts of pied or intermediate stages 

 were observed. At Cocos Island, Costa Rica, birds in the 

 light phase or in pied stages were very rare, even more so than 

 in the Galapagos Islands. 



In 1905 the northernmost locality in which we saw the Red- 

 footed Booby was latitude 20° 59' North, longitude 111° 57' 

 West, on July 23. This was in the general vicinity of San 

 Benedicto, Revilla Gigedo Islands, where the light phase of 

 the species occurs commonly. After leaving San Benedicto 

 the species was next met with in latitude 5° 43' North, longi- 

 tude 98° 44' West, on August 23, when a bird in the dark 

 phase was seen. Another was seen on the 24th, one on the 

 28th, and two on the 31st. On September 1st, when in the 

 vicinage of Cocos Island, they became common; all were in 

 the dark phase. 



In 1906, from the time we left Culpepper Island on Sep- 

 tember 25, until we were in latitude 19° North, longitude 116° 

 41' West, on October 24, Red-footed Boobies were seen daily 

 with but two exceptions. The first individual in the light 

 phase was seen on October 7, in latitude 14° 38' North, longi- 

 tude 109° 12' West, after which they were seen with more or 

 less frequency, particularly in the vicinity of Clarion Island, 

 Revilla Gigedo group. Judging from the dull colors of the 

 naked parts, practically all of the birds of the dark phase seen 

 after leaving the Galapagos group were immature. An occa- 

 sional immature bird with pale under parts was encountered. 



^Proc. Wash. Acad. Sci., v. 5, p. 247. 



