258 BULLETIN 121, UNITED STATES NATIONAL MUSEUM. 



Nesting. — ^Mr. W. Otto Emerson, in his notes sent to Major Bendire 

 says that on the Farallon Islands they begin to assemble about the 

 first of April or earlier if the season is favorable. 



They gather about the old rookeries and collect great pieces of dry kelp and 

 Farrallone weed to repair their old nests ; they may be a month or more about 

 the nests, adding bit by bit to the home ; sometimes all leaving for a fishing 

 trip to sea, then back again, sitting around the nests or on them; purloining 

 one from another's nest to add to its own ; bits of sea-moss and broken sticks 

 are stuck in the nest here and there. By the first of May some of the nests 

 contain eggs, both sexes sharing the. work of incubation, one staying on the 

 eggs to protect them from the thieving gulls, while the other is off fishing. I 

 found these cormorants to be the tamest of the three species on the island; 

 one can get up to within two feet of the nests. 



The tameness of the Farallon cormorant has been referred to by 

 several writers and a number of good photographs of birds on their 

 nests have been taken at short range ; this trait is not shared by the 

 eastern subspecies which is usually so shy that it is diflScult to come 

 within gunshot of one on its nest. 



Mr. Milton S. Eay (1904) describes the nests of this species, on 

 the Farallon Islands, as follows: 



The weed nests were like those of the gull but much larger and shallower, 

 measuring twenty inches across, the cavity being nine in width and three in 

 depth. I counted but forty-seven nests in the colony, which shows that the 

 number of these birds, now the least abundant cormorant on the islands, is 

 continually decreasing. On subsequent visits we noticed the birds did not re- 

 lay in the nests from which we had taken eggs. The gulls did not molest 

 the eggs and young in this rookery, for the reason the old birds did not 

 give them a chance, they settling back on the nest as soon as we passed it. 

 While it was interesting to watch these avian snakes in their summer home, 

 the decaying remains of numerous fish about the colony and the swarms of 

 seal-flies rendered it a pleasant place to be away from. 



A vast breeding colony of this cormorant was found on San Mar- 

 tin Island, Lower California, by Mr. Howard W. Wright (1913) ; 

 he made a careful estimate of the area covered by this colony and 

 figured that it occupied about 1\ square miles; then allowing one 

 nest for each 100 square feet, based on a count in an average meas- 

 ured area, he concluded that the colony contained the astonishing 

 number of 348,480 nests. This is certainly the largest colony of 

 cormorants of which we have any record. He says: 



We became very much interested in estimating the amount of fish these 

 birds consumed per day. We noted the amount each young cormorant threw 

 up when molested, and found on several occasions a bunch of fish as big 

 as a man's two fists. This mass was generally composed of surf fish, smelt, 

 and sardines. I have heard of other estimates of from three to six sardines a 

 day for a cormorant, so I consider a half pound of fish a day very conservative. 



Allowing half a pound of fish a day for each of the 1,800,000 birds, the 

 entire population would consume four hundred tons a day or about ten 

 thousand tons a month. The fishing was done in San Quentin bay, exclusively, 



