12 



THE AUDUBON BULLETIN 



it is necessary that the last date on which the eggs were in the nest be 

 recorded. This is shown by the following record: 



Section Five, Nest Eleven 

 catbird 



Shrubbery at right of walk, 8 feet from ground. 



May 21, one egg. May 22, two eggs. May 23, three eggs. May 29,. 

 three eggs. June 6, three birds. June 17, birds gone. 



"It cannot be told from the data whether the birds hatched on June 6, or 

 before. Had the record been, 'June 5, three eggs,' then there would have 

 been no doubt as to the day on which the birds hatched. Likewise for the 

 data to show the duration of brooding of young, which in this paper is 

 taken as the time interval between the hatching of the first bird and the 

 leaving of the nest by the last one, it is necessary that the last date on 

 which the young were still in the nest be given. It may be that in obtaining 

 the above record the nest was actually visited each day and that the birds 

 were seen to leave the nest, but so far as the record goes one cannot tell but 

 that the birds might have left the nest at an earlier date than June 17. The 

 following sample records illustrate the correct method of procedure : 



Section Five, Nest Two 

 meadowlark 



Hillside near track, runway N. E. down slope. 



April 18, one egg. April 19, two eggs. April 20, three eggs. April 

 21, four eggs. April 22, five eggs. May 3, four eggs (one gone). May 4, 

 two eggs, two birds. May 5, four birds. May 15, two gone, others left 

 nest at approach of observers. May 16, birds gone. 



