166 The Wilson Hulletin, No. 73-78. 



used this was very slight, in the south box where they nested 

 for two seasons a hole as large as a half dollar was made 

 through the half inch boards, which would have formed an 

 opening into the barn if it had not been for the batten back 

 of it. It is in the old east hole occupied for so many years 

 that this hacking is most prominent. I'elow the entrance 

 hole the siding of the barn in places has been hollowed out to 

 half its original thickness, and the board parallel to the raf- 

 ters, that helped form the cavity, has been cut half way 

 through in that portion of it that is opposite the hole. Evi- 

 dently this was done to enlarge the space ; the other cuttings 

 probably are the result of the bird's natural tendency to en- 

 large its nesting chamber while sitting, or it may originate 

 from the bird's habit of hammering with its bill at such times. 

 This hammering, which is often heard before the eggs are 

 laid, seems to be a call, and when done while the bird is in- 

 cubating it may be for the same purpose, since it appears to 

 be indulged in toward the close of a long sitting, when the 

 bird shows signs of restlessness by frequently going to the 

 hole to look out. 



