VOICES OF TROPICAL BIEDS FUEETES. 311 



oot, oot, oot — elp, elp', elp', ulp', ulp'." It was common, and, because 

 the forest was much opener and almost like our woods, it was much 

 easier to find and see. But, even so, many more were heard than we 

 were ever able to discern, and we never got over a feeling of victory 

 when we succeeded in seeing the singer. The color gradation was 

 so perfectly adjusted to the lighting in the woods that only a motion 

 was visible, and that scarcely. 



In the dark, fog-steeped forest along the culm of the Central Andes 

 a closely related species, darker in color, gave me one of the great 

 song sensations of my life. I heard a sharp, loud, " wip-wip-wip," and 

 ascribed it to one of the wood quail. I hunted it, unsuccessfully, 

 until I was discouraged and exhausted. Also I became dully aware 

 of a distant and long protracted whistle, which I vaguely attributed 

 to a steam whistle in some neighboring village. So does our common 

 sense become dulled when we are confronted by unfamiliar surround- 

 ings. On my tired way back to camp I realized that there were 

 neither mills, steam, nor villages in these mountains, which are un- 

 broken virgin forest for a hundred miles or more either way. Per- 

 haps I had heard a cicada. I could scarcely credit a bird with such 

 a prolonged sound as this. 



The next day I went back to solve the thing. When, after two 

 hours of steep ascent, I had reached the 8,000 foot level, I heard again 

 my mysterious whistle. Listening carefully, and imitating it as well 

 as I could, I was able to discern that the sound became definitely 

 more loud and distinct. No insect, this. Soon I could analyze it 

 quite closely, and found it to be a very gradually rising crescendo^ 

 beginning about on C, and a full though slightly throbbing or tremolo 

 whistle. I was astonished at its duration, for I could detect no time 

 at which a breath could be taken. Timing three successive songs, I 

 found them to endure 47, 57, and 53 seconds ! This was more than 

 twice the length of any continuous song I have ever heard, the win- 

 ter wren being second, with 28 seconds. But in this broken song there 

 are surely many opportunities to catch the thimblefull of breath a 

 wren can hold, Avhile the Cha7n(t'za song was one long, unbroken, and 

 constantly increasing sound. 



Eventually my singer came so near that I was afraid of scaring it 

 away by the imperfection of my imitation, which required a full 

 breath out, an in-breath to full lung capacity, and then the last bit 

 of breath I could expel to accomplish even a 40-second song. So I sat 

 silent, tense, and eager, hoping almost against hope that the mystery 

 bird would reveal himself. Suddenly, almost at my heels, a song be- 

 gan. Very soft and throaty at first, gradually rising and filling, the 

 steady throbbing crescendo proceeded until I was so thrilled that I 

 was afraid I couldn't stand it any longer. I dared not move, as I 



