NESTS AND EGGS 37 



studying their habits. A good opera glass will enable a person 

 to see a bird as well as though it were at half the distance. 

 When at a distance of fifty feet it can be seen as distinctly as 

 with the naked eye at a distance of twenty-five feet. Most 

 birds can be approached as near as fifty feet by a person who 

 has no gun and who shows by his actions that he does not in- 

 tend to harm them. 



This book is written chiefly to help you to recognize birds, 

 not to tell you all about them. But if you are interested in 

 the study it Avill be a great pleasure to you to learn all you 

 can about the birds that frequent your locality. Through book 

 study alone no complete knowledge can be gained of birds or 

 indeed of any animals. On the other hand, there are facts 

 about the life history of migratory birds as Avell as the distri- 

 bution of all birds, which can be learned only from the com- 

 bined observations of many people, in many places, and so can 

 be acquired only by reading. After you know a bird well 

 enough to recognize it easily, it might be well for you to read 

 a little about it, then watch it, listen to its song, examine its 

 nest, observe all its habits. After that you will be ready to 

 read with advantage and appreciation anything that has been 

 written on the subject by creditable authors. 



When examining birds' nests and eggs, do not handle them. 

 It does no good, and may cause the bird to desert the nest. 

 After the young birds have left the nest, you can without any 

 harm secure it for your cabinet. In the chapter on preserving 

 specimens you will find directions for cleaning eggs. Any 

 extensive collections of eggs by students generally should 

 not be encouraged; no eggs should ever be gathered without 

 certain knowledge of the species of the bird. Such eggs are 

 absolutely worthless for a collection. The variety of eggs 

 which a single species lays is in many cases very great, and 

 the number of species which lay similar eggs is also great, 

 so there is no certain way of determining eggs except by obser- 

 vation of the birds. Your love for the birds, your feeling of 

 horror at their useless destruction, and your desire for their 



