256 BULLETIN 121, UNITED STATES NATIONAL MUSEUM, 



of one of the other and apparently more usual nesting site of this species — a 

 rather narrow ledge of broken shelving rock at the foot of a precipice or over- 

 hang. Apparently any relatively flat space sufficiently large to accommodate 

 the nest may be utilized, either upon the sharp ledge or precipice's foot. A 

 careful scrutiny of any of the nests shov^n will reveal the fact that one of 

 the prime requisites in a nesting site for the individual nest Is that on one 

 side the ground or rock must fall abruptly away. It is on this side that the 

 excrement forms a limy smear, often extending many feet below the nest 

 The uphill side of the nest is always relatively clean. 



Nests are made of coarse sticks arranged much after the manner of a hawk's 

 nest, cupped to the depth of five or six inches, and with a lining of grassy ma- 

 terial which covers scarcely more than the bottom of the depression. The sticks 

 used were such as might have been found upon the island, and the grass seemed 

 to correspond to that within a short distance of the colony. There was no evi- 

 dent attempt at concealment In any case, nor was there any clear indication 

 that any nests were placed with a view to shelter either from the weather or 

 from the scorching rays of the sun. The evident distress of both old and young 

 birds when exposed to the direct sunlight would certainly afEord excuse enough 

 for seeking a shady nook among the rocks. The very young birds were nearly 

 baked when left uncovered for any great length of time. One such died under 

 our eyes, evidently from the heat. 



The varying ages of the young — none of which were yet feathered — and the 

 fresh eggs in a nest which showed no signs of having been a victim of the 

 pilfering crows, both point to the conclusion that there must be a great deal 

 of individual variation In the time of nesting of these birds. It is true that 

 nests containing fresh eggs may represent a second set after the loss of the 

 first one, but the fact that none of the young birds were anywhei-e near ready 

 to leave the nests seem conclusive that only one brood is reared in a season. 

 The nesting season was too far advanced to afford any opportunity for study- 

 ing nest building or egg deposition. 



The colony shown in Figure 1 was shared by a few California murres who 

 occupied the spaces between nests which were level enough to keep an egg from 

 rolling into the water, or off from the ledge. There was no apparent discord in 

 such a mixed colony, even though the murres were within reach of the weapons 

 of the cormorants. In one other place the same conditions prevailed. I could 

 discover no reason for regarding this as a case of true communalism. If there 

 was any benefit derived from this association it must have been to the advan- 

 tage of the murres. 



Besides these two nesting sites there were a few small ledges on the ocean 

 side of the island where we found nests of this species, usually not more than 

 two or three nests together. Here there was some distant intimacy with 

 Baird cormorants, but the different manner of nesting of these two species 

 precludes the possibility of any competition between them. 



The perpetual noises made by the birds of the island seriously interfered 

 with any careful study of the various notes of these cormorants. When the 

 old birds were disturbed or alarmed they gave vent to a spluttering squawk 

 and often a low grunting. The young yelped something like a puppy, particu- 

 larly when they were calling for food. They Were usually silent when crouch- 

 ing away from danger. The very young birds showed no fear, but the older 

 ones clearly did. 



Eggs. — The eggs of this subspecies seem to be scarce in collections. 

 They are apparently indistinguishable from eggs of the other sub- 



