THE LURE OF FIELD WORK 65 



ing explanation: all birds build their nests in what 

 they suppose X° be secure, sheltered locations. 

 Very frequently they make mistakes, but with the 

 shy, wild birds which I have pictured for the greater 

 part, every nest location is chosen in the parting 

 twigs, the crotch of a branch, or some place se- 

 cluded and sheltered by leaves, roofs, rails, bridges, 

 or embankments. The instant any mother bird 

 at work on a nest feels that her location has been 

 discovered she deserts that spot and begins a new 

 one somewhere else. Always, in the work of nest 

 building, she is in motion, either carrying material 

 or weaving it into a cup, patterned around her 

 breast, so that no picture of her is possible except 

 through instantaneous exposure. To change the 

 surroundings of a building female by the bending 

 back of branches to let in sufficient light for in- 

 stantaneous work would simply mean to drive the 

 bird to the selection of a new location. She would 

 not return to her first spot when a camera, however 

 skilfully concealed, had been intruded, and brilliant 

 sunlight was shining on the structure she had begun 

 in deep shade. 



I have made more or less complete series of the 

 home life of the larger number of our shyest, wild- 

 est song birds of the interior. It is a far greater 

 feat to secure a characteristic likeness of one of 

 the song birds of deep wood or field than to point 

 a camera at a flock of ocean or gulf birds and secure 

 a thousand on a plate. 



