FLORIDA BOAT-TAILED GRACKLE 363 



to the sound produced by a Coot in pattering over the water". * * * I noticed 

 that the bird * * * vibrated or slightly fluttered its wings, so that their tips 

 appeared to strike either together or against the upper side of the tail. At the 

 same time the bill had the appearance of partly closing. I therefore concluded 

 that the sound was not vocal, but wing-made; a number of subsequent observa- 

 tions strongly confirmed me in this opinion. 



It was not until my last morning in Florida * * * that I was undeceived. 

 I then had an excellent view of a bird * * * and saw that its wing-tips did not 

 touch during the final part of the song, though they vibrated a little. A little 

 later another bird * * * did not appear to vibrate its wings at all * * *. I 

 could plainly see the bill in a sort of rattling motion, however, and finally realized 

 that it was the rapid striking together of the mandibles that produced the sound. 



Almost identical with Harper's first impresions and following 

 conclusions, are those of Bradford Torrey (1894) who says, in writing 

 of this sound, "that the sounds were wing-made I had no thought of 

 questioning. Two days afterward nevertheless, I began to doubt. 

 I heard a grackle 'sing' in this manner * * * wing-beats and all, 

 while flying * * * and later still, I more than once saw them produce 

 the sounds in question without any perceptible movement of the 

 wings, and furthermore, their mandibles could be seen moving in 

 time with the beats. * * * My own * * * conjecture is that the 

 sounds are produced by snappings and gratings of the big mandibles." 

 Townsend (1927), who quotes both Harper and Torrey on the matter 

 studied the sound both in Florida and South Carolina, and he too was 

 at first under the impression that the noise was wing made, for he 

 says in his field notes that "they flutter their wings slightly, making 

 instrumental music in the form of a rattle." Later observations, 

 however, caused him to change his mind, for he says : 



On several occasions I noticed that during the rattle the wings were sometimes 

 moved but little, or were motionless. Once or twice I saw one wing slightly 

 elevated but not vibrated. I also heard the rattle many times given in flight, and 

 there was no perceptible modification of the actions of the wings at the time. I 

 think it can be definitely stated therefore, that the evidence eliminates the wings 

 from any causative action of the rattle, although the vibrating movement is 

 generally present and exactly synchronous with it. * * * But my observations 

 lead me to think that the rattle is vocal, modified by throat vibration and not 

 made with the bill. 



Enemies. — S. A. Grimes of Jacksonville, Fla., writes that at times 

 nests of the Florida boat-tail are invaded by black ants. He says 

 that while examining a colony near Jacksonville Beach, "the northern- 

 most outpost of the brown-eyed birds," he found that "black ants 

 had taken possession of all the nests, filling the interstices with their 

 larvae and pupal cocoons. Only one grackle had held out against 

 the ants. The eggs in her nest were pipped, but it was evident the 

 young stood little chance of survival." 



These specific reasons why many young do not survive hardly 



