Introduction. xvii 



The higher animals thus start in life with a definite equipment, a body tuned to 

 respond to the world in which they are placed, and this ingrained ability for action may 

 be called instinct. 



In speaking of the " habits " of animals we usually mean the manner of their life in 

 general, while a " habit " in the technical sense may be regarded as a mode of action which 

 the animal has learned or acquired. It is associated with pleasure, and in the course of 

 repetition may become more or less fixed or " stereotyped." In this sense habits are 

 formed out of the raw material which heredity provides. The young bird learns to eat 

 certain things, to avoid certain enemies, to start at certain sounds, to ignore others, to 

 approach its nest in a certain way. Thus also the vertebrate sometimes acquires the 

 habit of walking backward, while its instinct leads it to walk forward. 



Habits must in time take the place of instincts in a very large measure, and it would 

 not be strange if a Robin's second nest were more nearly perfect than its first, or if the 

 third were better than the second, but this would also depend upon other conditions. 



The power of forming habits is a sign of intelligence, but not necessarily of reason. 

 The intelligence may be a small grain and never destined to grow into a flourishing tree 

 of knowledge, but it must exist along with the power of profiting by experience. 



The mental faculties of birds seem to exhibit a wide range of gradation from exces- 

 sive stupidity to a fair degree of intelligence, with strong associative powers, rarely if 

 ever the association of ideas, but of things with actions, and often with wonderful 

 powers of imitation. 



The habits acquired by one generation are probably never handed on to the next, 

 but this is a subject from which the dust of argument has not yet cleared away. 



II. 



That a bird in the hand is worth two in the bush may be a good motto for the an- 

 atomist or epicure, but for the observer of living animals a bird within reach of the hand 

 and still in the bush is of far greater worth. The problem is how to see and not be 

 seen. If a bird is actually caught and kept in a cage or put under restraint in any way, 

 its behavior is no longer perfectly natural and free, at least not until all fear has been 

 subdued and it is no longer wild but tame. What is needed is an invisible chain which 

 shall hold the animals to some fixed and chosen spot which can then be approached in 

 disguise. 



Fortunately for the student of bird-habit and instinct all these conditions are fulfilled 

 for a most important and interesting period, that of life at the nest. The nest is the 

 given fixed point, and parental instinct is the invisible chain. The wild bird, however, 

 is bound not merely to the nest, but to its young. Wherever the young go, the old birds 

 follow. By using the nearly fledged young as a lure, some species could, I believe, be 

 led across country for a mile or more. I have taken them two hundred feet without 

 special effort. 



Hitherto the bird-photographer has had to rely mainly upon chance in getting a 

 picture of the nesting scenes. Most land birds depend upon concealment for protection 

 from their enemies during the season of young. Their nests are apt to be shrouded 



