98 BOARD OF AGRICULTURE. [Pub. Doc. 



swiftly that the young are fed before the pressure on the bulb 

 or the pull of the thread has exposed the plate. In not a few- 

 cases the exposure comes so late that the parent bird is no 

 longer in the field of the camera, and only the nest or young 

 are shown. Often the parent bird stops after feeding to look 

 about a little or to clean the nest, and then it is that most of 

 the good pictures of adult birds at the nest are taken. To 

 photograph insects the camera must be very near the nest, 

 that the impression on the sensitive plate may be large enough 

 so that the insects seen may be identified as belonging to cer- 

 tain groups. Then there is very little depth of focus, and unless 

 the bird's bill is exactly in focus the impression of the insect 

 or insects will not be sharp. This year a liberal use of blinds 

 and the employment of various stratagems produced some re- 

 sults, but the weather of June and July was so stormy and 

 clouds so overcast the sky that often instantaneous photography 

 was unsuccessful. Hardly one negative out of ten was perfectly 

 satisfactory, but some excellent ones were secured. Such nega- 

 tives are valuable for the making of lantern slides to show the 

 utility of birds, and are worth all that they cost. 



A common method of securing photographic records of the 

 food of a bird is to kill the bird, empty its stomach or its crop 

 or gullet, spread the contents out on white paper and so photo- 

 graph it. The contents of the stomach in such a case, however, 

 are likely to be more or less macerated and torn, and much of 

 them cannot be recognized except by an expert. Often, on the 

 contrary, the crop or gullet contains insects, seeds, etc., which 

 have been changed little, if any, in appearance since they were 

 swallowed. 



Charles P. Curtis of Boston was kind enough to forward 

 to me on September 7 the crop of a bobwhite that had been 

 killed while on its nest in Connecticut by a mowing machine. 

 It contained 48 Colorado potato beetles {Doryphora decein- 

 lineata) and about 250 seeds of different species of weeds. 

 The stomach was not saved. It may have contained remains 

 of as many more. The bobwhite is a well-known destroyer of 

 potato beetles, other pests and weed seeds, but there is nothing 

 so convincing as a photograph of the crop contents. A farmer 

 who has watched closely the habits of this bird believes that 



