Page:The Singing Tree - William Henry Mousley - The Auk 36(3) - P0339-p0348.pdf/10

348 (Dendroica carulescens corulescens) in my experience are certainly incessant singers, but the Black-throated Blue differs in many respects from the other two, as he seems to affect denser foliaged trees, and usually sings higher up and is what one might call not a home bird, as I have generally found him to sing much further away from the next than any of the other Warblers. Still in his case if you are familiar with the sites usually selected for nesting, the 'singing tree' or trees will always give you a clue; the only thing you must do is to be somewhat more elastic with regard to the magic circle. In the case of a nest I found this year I could see from the nature of the ground beneath the 'singing trees' that a radius of twenty yards failed to bring me within any site at all likely to hold a nest, the ground being much too open; but by doubling this distance I came within some very dense undergrowth, and this I knew from experience was just the very sort of ground a female Black-throated Blue Warbler would be likely to select. I therefore measured out forty yards, but even this was not quite enough, for the nest was eventually found at fifty yards from the nearest 'singing tree,' and ninety yards from the furthest. I mention this case in order to show that there are times when experience and a little common sense must be displayed if good results are to be expected.

In conclusion it may be stated that in the case of birds that sing in the air such as Prairie Horned Larks, I have found their nests by constantly noticing the male frequenting a certain observation post, usually consisting of a large stone or boulder, although in one case it was actually a tree (see 'Auk,' vol. XXXIII, 1916, p. 285), and from there measuring out the required distance and then walking quietly over the ground), looking well ahead for the female to slip off the nest. Of course it may be necessary to repeat this proceeding several times before she is eventually found at home, but in the meantime there is always the off chance of the nest being discovered quite irrespective of the female whilst quartering the ground. This method can be adopted equally well with Spotted Sandpipers (Actitis macularia) as I found two nests, one in 1914 and the other in 1915, the observation post of the male in each case being a heap of stones in a field adjoining 'the marsh.'