346 Mousley, The Singing Tree. [July 



being able to further test the reliability of my system. Having 

 watched him for some time and convinced myself that the birch 

 tree was really the favored one (although there was a tall hemlock 

 with dead branches also not far off, which was almost equally used), 

 I proceeded to measure off the prescribed distance as already 

 indicated. This being done and the ground, which was truly a 

 warbler one, inspected, I noticed that on the c eastern side the trees 

 were taller than the birch or ' singing tree,' and therefore the latter 

 did not dominate this part of the circle, and in all probability the 

 nest would not be there. In passing, it may be well to mention 

 that the 'singing tree' does not always necessarily dominate the 

 nesting one, although I have generally found it to do so, an ex- 

 ception being that of a male Purple Finch (Carpodacus purpureus 

 purpureus) who sang from an apple tree on the opposite side of the 

 spruce tree in which the nest was placed, but in this case there were 

 no trees overlooking the nest at all. Surely the male had no voice 

 in selecting that site (although he undoubtedly did the 'singing 

 tree,' as he had frequented it often previous to any nest being 

 started in the spruce), invisible as it was to him whilst singing! 

 But there, that opens up another interesting problem, and I must 

 get back to the work in hand. After watching the male Bay- 

 breast for some time, I noticed that he generally faced either north 

 or south, whilst in the two 'singing trees,' more generally the latter, 

 and I concluded that somewhere in that direction the nest would 

 eventually be found, as it was an absolutely ideal spot. Now 

 in the lower branches of the hemlock tree a male Magnolia Warbler 

 ventured to sing on several occasions, but was always driven 

 away by the Bay-breasted Warbler. This looked suspicious and 

 I overhauled the firs and spruces in close proximity, with the result 

 that the female Magnolia was flushed from her nest and set of four 

 eggs only seven yards away from where the male had attempted 

 to sing. 



Time was flying fast, however, and still no signs of the female 

 Bay -breasted Warbler, until a sudden downward swoop of the male 

 to the south, brought her out to the east, and I was able to follow 

 her about for a short time, until she eventually gave me the slip. 

 Then I began to search the southern site more carefully, from 

 which direction I had also just previously heard some Thrush-like 



