A New Method of Bird Study and Photography. 



1 1 



measurements, or photographs of the birds themselves, place the matter in a different 

 light. With these objects in view the nest must be frequently approached and the young 

 taken out, and for such studies the change of the nesting site offers such obvious advan- 

 tages that it is needless to dwell upon them. In taking down the nesting bough it is 

 often necessary to touch the nest, and this does no harm. 



Young birds eight or nine days old stand the heat well, provided they are fed, but on 

 very hot days they should 

 not be allowed to go with- 

 out food for more than 

 two hours at the longest. 

 Should the parents bring 

 no food during this time, it 

 is better to feed the young 

 in the nest, and to suspend 

 operations until the next 

 day. 



As has been already 

 said, the old birds may be 

 expected to come to the 

 nest in from twenty min- 

 utes to an hour, when the 

 tent is brought into imme- 

 diate use after removal of 

 the nesting bough. It is 

 naturally impossible to 

 predict exactly what will 

 happen in any given case 

 until the experiment is 

 tried, since the personal 

 equation or individuality 

 of the birds themselves is 

 an unknown and variable 

 factor. One thing only is 

 certain, that the parental 

 instincts, reenforced by 

 habit, will win in the end, 

 that they will cast out fear, 

 and draw the birds to their 

 young. 



I have used the tent and altered the nesting site in the case of twenty-six nests 

 belonging to fifteen different species of birds. The experiments were Extent of Appli- 

 made in the course of two seasons, and the entire list is tabulated as cation of the 

 follows, the age of the young in most cases being only approximately Method, 



accurate : 



Fig. 9. Cedar-bird at nest shown in Figs. I, la, and 13, prepared to feed young 

 by regurgitation : a characteristic attitude. The parallel outlines of the neck 

 show that the gullet is full. 



