Phoebe vs. Catbird 



271 



the Swifts (litl not yield, but jilastcrcd their nests to sooty l^ricks instead of 

 to crumbHng wood; Night-hawks found level gravel beds on the roofs of tall 

 buildings, and the Martins, Wrens and Bluebirds found nesting-holes in eaves 

 and gutters. Thus one might multiply examples until he recognized two 

 groups of birds: the one w^hich is able to adapt itself to changing conditions, 

 the other which succumbs to them. 



The Catbird is a bird of the thickets. Lurking in the densest vines and 

 brambles, it comes out only to scold at an intruder or to sing. So long as 

 the hawthorns, grape-vines or 

 berry bushes survive, so long 

 will the Catbirds ; but when 

 these disappear, the Catbird 

 goes with them. 



The Phoebe is a bird of 

 the cliffs and gorges. Its nest 

 of mud and moss was found 

 originally only where the 

 shelving rocks of an exposed 

 ledge protected it from above 

 and below. In such places it 

 is still the most abundant 

 bird; but with the appearance 

 of culverts and bridges, the 

 Phoebe found these places suit- 

 able for its nest. In fact, it 

 goes even a step further and 

 builds its nest about houses 

 and barns wherever it can find 

 one ledge to support and 

 another above to protect it. 



There is a road w^hich 

 skirts the border of a certain 

 marsh. On one side is a 

 dense, almost impenetrable, thicket where the Catbirds nest and are almost 

 as abundant as the Sparrows in the town hall. On the other side rises a rather 

 low but perpendicular cKff where the Phoebes build. While photographing 

 one of the Phoebe's nests, it occurred to me that some object placed upon the 

 nest might prevent the bird from returning until after inspecting from the 

 adjacent branch. Here the light was stronger and would permit of a more 

 fully timed exposure. Accordingly a strip of yellow cloth about eighteen 

 inches long was placed over the nest with one end lightly tucked into a crevice 

 to prevent its blowing away. The Phoebe returned to its chosen perch on a log 

 and was about to fly to the nest when it espied the rag. Here was something 



■HCEBE IXSPECTIXG FROM THE END OF A 

 XEAR-BY LOG 



