ANIMAL BEHAVIOR, WITH EXAMPLES 243 



about decided to cut off for preservation the branch bearing the 

 oriole's nest. To sever the Hmb I had devised a wooden pole 

 with a small hand scroll saw fastened to the end. When about 

 to start the sawing, I noticed a house wren fly to the opening of 

 the nest, carrying some moths in her bill. A moment later 

 she disappeared within the nest, where she undoubtedly emptied 

 the tit-bits into some little upturned mouths, for she soon 

 emerged with no trace of the moths in her mouth. I saw both 

 parents repeat these visits several times and I became satisfied 

 that the wrens had adopted the oriole's nest as their own home. 

 In another chapter, entitled "An August Hailstorm and Its 

 Sequence," I have given a further account of these birds. 



A nest of the mourning dove, which had seemingly been 

 entirely vacated by the owners, was singled out to be taken 

 for a friend who had a hobby for nest collecting, but through 

 a change of plan the empty nest, which was built in an apple 

 tree, was left unmolested. Later, while incidentally making 

 observations, the mother was found to have again returned 

 to the nest and had laid two eggs. ^Yhat a lesson is taught 

 here! It is from such facts as these that I have learned never 

 to appropriate seemingly abandoned nests when they could 

 possibly be used again by their owner or by some other bird 

 or mammal as a home. 



As I visit the nesting birds the time seems to fly only too 

 swiftly. A day or two ago I observed eggs in the nests of the 

 catbird, song sparrow, and indigo bird. Now I view the curious 

 little worm-like new-born young instead of the eggs in the 

 nests. How rapidly they lose their downy coats! In another 

 few days the little wings will be arrayed with quills, and before 

 one realizes it the birds will be nearly ready to fly, or perhaps 

 they will have gone from their nests before our next belated 

 visit to their homes. 



Many birds are exceedingly sensitive to any human intrusion, 

 as I found to my sorrow one day. A pair of field sparrows 

 had built a nest in a bush along a fence row. Almost 

 immediately after the nest was completed, a cowbird deposited 

 one of her eggs in it. I left this egg and watched developments. 

 The field sparrow seemed to pay but little attention to this para- 

 site's egg and went on laying her own full set of four. Now, with 



