Nov. 1884.] 



AND OOLOGIST. 



131 



it is evident that the first series indicates 

 the arrival of the bulk of the males, while 

 the second indicates the increase of the 

 species as a whole, caused by the arrival of 

 the females ; May 5th, bulk of females ar- 

 rive and many transients, making this day 

 the height of the season — as has already 

 been stated, this day and the nest are the 

 days of movement for this species, and 

 this seems to be true over an immense 

 country, stretching from 34° to 44° ; May 

 10th, first male of last year : May 11th, 

 species very much excited and transient 

 birds of last year present ; May 31st, set 

 found of six incubated eggs. — W. W. 

 Cooke. 



Bird Nesting on "Bird Island," Cal. 



The undersigned, in company with Mr. 

 A. M. Ingersoll, started on the 28th of May 

 for ''Bird Island," an island situated near 

 the end of Tomales Point, Marin Co. This 

 island is about one hundred and twenty- 

 five yards from the main-land ; it is a barren 

 rock entirely destitute of vegetation, and I 

 should judge from my observation of it, 

 that it is about an acre and a half in area, 

 although it may be less, and its highest 

 point is about fifty feet above the sea level. 

 As we viewed the island from the shore it 

 appeared to be one mass of birds, princi- 

 pally Cormorants and Gulls. As we 

 approached, the Gulls and Oyster-catch- 

 ers uttered their shrill notes, and by 

 the time we had reached the island it was 

 in commotion, the birds flying over our 

 heads in every imaginable direction, the 

 majority, however, soon returned and lit 

 on the water about a hundred and fifty 

 yards from the island, but cpoite a lot of 

 them kept continually flying over our 

 heads. 



The sight on the island is one that I 

 shall never forget, and to any person who 

 has never before witnessed such a sight, it 

 is truly wonderful. 



The birds that were breeding on this 

 island consisted of the following kinds, 



Brant's and Baird's Cormorants, Western 

 Gulls and about twenty pair of Tufted 

 Puffin were breeding in the burrows which 

 were situated on the banks that surrounded 

 some parts of the island. The burrows 

 extended into a depth of about four feet, 

 at the end of which they deposit a single 

 egg on the bare earth. We only obtained 

 eight of their eggs, as our time on the 

 island was limited, and it generally takes 

 from Ave to ten minutes to obtain one of 

 them. The burrows never run straight, 

 but nearly always curve just before the 

 nest (if such it can be called) is reached. 

 The two species of Cormorants each in- 

 habited different parts of the island, the 

 Brant's occupying the eastern side and the 

 Baird's the western side thereof. The 

 Brant's greatly outnumbering the Baird's. 

 The nests were situated about eighteen 

 inches apart and in straight rows of about 

 thirty feet long, but I presume that as the 

 season advanced they would greatly in- 

 crease in length, as a great many of the 

 Brant's had just commenced to form their 

 nests. The Baird's I think are about a 

 week earlier in their breeding habits than 

 the Brant's, as nearly all the nests of the 

 Baird's had full sets, while with the Brant's 

 such was not the case. The usual comple- 

 ment of eggs consisted of from three to 

 four. We only obtained two sets of five 

 I believe, one of Brant's and one of Baird's. 

 The nests were composed principally of 

 seaweed and lined with sea grass. The 

 eggs of these two sjjecies are indistinguish- 

 able from each other in regard to size and 

 color, the only way therefore to be posi- 

 tive of their identity is to shoot the birds. 



We obtained about two hundred eggs of 

 the Brant's Cormorant and about one hun- 

 dred and thirty of the Baird's. 



The Western Gulls, (the only kind that 

 were breeding on the island), were not so 

 regular in their breeding habits, their nests 

 being scattered promiscuously over the 

 whole islands. The majority of the eggs 

 were well advanced in incubation, and I 



