FLORIDA BOAT-TAILED GRACKLE 361 



"anchored * * * off the mouth of Bayou Michow. Near the boat 

 was a stake * * * on which a swallow had alighted. A male Boat- 

 tailed Grackle flew out from land, coming to the stake to alight. The 

 swallow did not move until the Boat-tail was almost upon it, when it 

 spread its wings, but the Boat-tail gave a quick snap and killed 

 it * * *. The grackle sat on the stake a half minute or so looking at 

 its victim floating on the water, then swooped down, picked it up and 

 went ashore with it." He adds that he has "frequently seen male 

 Boat-tailed Grackles feasting on ducks that had been killed and drifted 

 to shore." The muskrat trappers of Louisiana complain that these 

 birds ruin the pelts of caught animals by pecking into them and eating 

 the flesh. The writer heard many such complaints from trappers in 

 Cameron Parish when investigating muskrat trapping there in 1934, 

 and was shown some animals which had been thus disfigured. 



Injured birds are taken by the boat-tailed grackle when opportunity 

 offers, and Mcllhenny lists broken-winged red-backed sandpipers 

 (Pelidna alpina sakhalina) as such victims. Even its neighboring 

 redwings are not safe from it, as the same author has seen grackles 

 devour young in the nest while the impotent parents strove vainly 

 to drive away the marauder. It is also a confirmed egg thief and 

 seeks out heron, egret, and other such nests to indulge this appetite. 

 On the Texas nesting islands I have often seen the boat-tailed grackle 

 despoiling nests of the reddish egret. In such instances it is not so 

 much the predation of the grackle as the attitude of the egret which is 

 interesting, for the latter simply stands by with a most fascinated 

 expression and calmly watches the proceedings, making not the slight- 

 est effort to interfere with them! 



Much to my surprise, I discovered osprey-jaeger tactics among 

 these grackles in the Lake Okeechobee area, in Florida, while con- 

 ducting Audubon wildlife tours there in 1941. One of the tour routes 

 lay along the road which skirts the northern shore of the Lake and a 

 great attraction of it was the fact that flocks of feeding eastern glossy 

 ibis (Plegadis guarauna) were to be seen every trip. These flocks, 

 often associated with snowy egrets (Egrelta thula thula), were attended 

 by numbers of boat-tails as they probed about for crayfish. 



When an ibis secured a crayfish it would, instead of gulping its 

 prey at once, spring into the air and fly upward. Instantly, it would 

 be beset by grackles which almost invariably either snatched the 

 cra}^fish from the ibis's beak or forced it to be dropped, whereupon 

 another of the tormentors would seize it. This victimization, not 

 simply an isolated occurrence, was indulged in regularly and we saw 

 it many times. Always, from the observer's standpoint, it was a 

 spectacular performance, and at some little distance the birds looked 

 like great grains of dark corn popping from a giant popper. 



