234: FRIENDS WORTH KNOWING. 



concealed the sitting bird were at a considerable distance 

 from any house in uncultivated parts. In all such local- 

 ities sparrow-hawks were seen frequently, as compared 

 with the neighborhoods selected for building the shallower 

 open-topped nests, all of which were in willow or elm trees 

 in the yards of farm-houses. The conclusion drawn was 

 that the orioles knew where danger from hawks was to be 

 apprehended, and constructed accordingly the less elabo- 

 rate nest in the farmer's yard answering every purpose for 

 incubation. Dr. Abbott says, however, that of the nests 

 that did conceal the sitting bird, every one was really open 

 at the top, and the bird entered from above. Its weight, 

 when in the nest, appeared to draw the edges of the rim 

 together sufficiently to shut out all view of the occupant. 

 It is his opinion, however, that years ago, w T hen its enemies 

 were more numerous, the nest of this oriole was perfectly 

 closed at the top, and with a side opening ; but he finds 

 none so now. 



The question why this species alone among our birds is 

 supposed to have learned by dear experience to take such 

 precautions against its foes has already been answered : it 

 is because the Baltimore oriole is almost the only species 

 in which the female is not protected from observation by 

 her neutral and dull colors, and in which the brightly phi- 



