4 BIRD'S-NESTING. 



surety that the species of bird to which the eggs 

 belonged was accurately identified, and that the spec- 

 imens themselves have subsequently been carefully 

 authenticated. 



The nests of birds are to be sought for in all lo- 

 calities, and in various months of the year according 

 to the latitude, April, May and June being the most 

 productive. Many of the rapacious birds,. however, 

 begin to lay much earlier, even in February and 

 March. Everywhere the lateness or forwardness of 

 the season correspondingly retards or hastens the 

 date of incubation to a considerable degree ; and, as 

 a rule, the nesting season on the Pacific coast is 

 several days earlier than on the Atlantic. 



If you limit your collecting trips to the immediate 

 vicinity of your home, your observation will tell you- 

 when the birds are beginning to build, and when the 

 eggs are to be had. You will discover that, for about 

 a fortnight, if you wish good, fresh specimens, you 

 must work with great zeal, wasting not a single 

 moment. If you delay, the mother birds will begin 

 to sit upon their eggs, the embryos will begin to be 

 formed, and when this has gone on for a few days 

 the preservation of good specimens is very difficult. 

 After the middle of May, therefore, constant vigi- 

 lance should be exercised, and the eggs of all the 

 earlier breeding birds be taken at once, in order to 



