THE OOLOGIST 



121 



limed ground had had a material ef- 

 fect on the coloration of the eggs. 

 The young in this brood hatched about 

 the 11th and on the 20th a young bird 

 was killed and dissected and a result 

 similar to the young of the second and 

 third broods was obtained. 



Three stomachs of the adults were 

 examined on this day and the average 

 of the stomachs was as follows: Corn, 

 64%; Beetles, 15%; Vertebrates, 20% 

 and Invertebrates 1%. 



The remaining four nests were lo- 

 cated between the 28th and 30th and 

 the eggs in each of these cases were 

 of the light phase, but were all heavily 

 speckled with brown and lavender and 

 the eighteen eggs averaged 1.59x1.14. 



Four young were taken from these 

 four nests at the age of eight days 

 and their stomachs were examined 

 and the following average was secur- 

 ed: Corn, 35%; Beetles, 22% Lepl- 

 doptera, 12% Vertebrates 5%; Orth- 

 optera 20% and Invertebrates 6%. 



On the 18th of June five stomachs 

 of adult males were examined and 

 the following result obtained: Corn, 

 55%,; Beetles, 21%; Invertebrates, 

 12% and Vertebrates 12%. 



The foregoing observations and ex- 

 aminations brought forth the follow- 

 ing facts: 



First: That the eggs of the dark 

 phase demanded a period of incuba- 

 tion of approximately fifteen days and 

 the light phase from thirteen to four- 

 teen days. 



Second: That where the adult fe- 

 males fed on limed ground for a per- 

 iod of no less than two weeks, the ef- 

 fect of the lime was clearly indicated 

 in the coloration of the shell of the 

 eggs. 



Third: That the food of the young 

 birds at the age of eight days averag- 

 ed: Corn, 29%; Beetles, 20.5%; Spid- 

 ers, 8:5%; Orthoptera, 17.5%; Inver- 

 tebrates, 4.25%; Vertebrates 13.25% 

 and Lepidoptera 7%. 



Fourth: That the food of the young 

 birds at the age of twenty days aver- 

 aged: Corn 38.5%; Beetles, 27.5 7o; 

 Lepidoptera 11%; Spiders, 12.5%; In- 

 vertebrates, 2.5% and Vertebrates, 

 8%. 



Fifth: That the food of the adult 

 males, thirteen stomachs in all, dur- 

 ing the period between the 20th of 

 -May and 18th of June, contained the 

 following: Corn, 62%; Beetles, 17%; 

 vertebrates, 13%; Invertebrates, 7%; 

 Lepidoptera .4% and Spiders, .6%. 



Sixth: That, while the food of the 

 young birds during their life while in 

 the nest contained about one-third in 

 corn, the remaining two-thirds were of 

 a class which are helpful rather than 

 detrimental to the corn grower in this 

 section. On the other hand, the food 

 of the adults, in which the corn diet 

 approximated two-thirds, the birds in 

 this case are proven detrimental dur- 

 ing the early stages of the corn grow- 

 ing and every safeguard against them 

 and their inroads should be adopted 

 to decrease this percentage. 



In all forty-six eggs were measured 

 and the averages in size of these were 

 1.61x1.15. 



Louis S. Kohler. 



Socorro Petrel Captured at Sea. 



Last Saturday evening, April 1st, I 

 was on the hurricane deck of the 

 "Steamship Queen" bound for Los 

 Angeles, when a heavy fog fell upon 

 the deep. We were moving slowly 

 in the Santa Barbara Channel and the 

 islands could be faintly seen through 

 the mist. Suddenly, a Socorro Petrel 

 (Oceanodroma Socorroensis) flew into 

 the cabin and dropped into a ladies 

 lap. Believing the object a bat, she 

 uttered a piercing scream. I ran be- 

 low and captured the bird before the 

 passengers could destroy it. It is a 

 male species and is now in the Mu- 

 seum of History, Science & Art in 

 Los Angeles. 



