364 U. S. NATIONAL MUSEUM BULLETIN 211 



suffice to explain the high mortality among nestling boat-tails. Facts 

 on this phase of the life history are almost totally absent from the 

 literature. I must confess never having mentioned it, and in this 

 respect am as much at fault as any. Mcllhenny (1937), who has 

 spent much time in observing the bird and its habits in Louisiana, 

 found in a detailed study of 74 nests on Avery Island, La., that success 

 in raising young was only 54 percent; only 20 nests raised 3 young 

 from that number of eggs; 26 raised 2 young; and 5 nests, 1 young. 

 In 23 nests the entire setting was lost; nor could he discover the reason. 



One possible cause for the loss of eggs is suggested by Grimes' 

 notes. He states that while investigating nesting boat-tails in the 

 Amelia River marshes of Florida he found "six or eight nests, some 

 with and others without, fragments of eggshells. * * * Worthington's 

 Marsh Wrens (Telmatodytes palustris griseus) were numerous in the 

 marsh and may have been guilty of the egg puncturing." 



Mcllhenny (1936) lists the purple gallinule (Ionornis martinica), 

 as well as "many other species," as preying on young boat-tails, and 

 gives the following interesting example: 



On Sunday, May 10, Stanley Solar and I were observing a large colony of nesting 

 Boat-tailed Grackles. * * * We had already remarked the large number of 

 empty nests, that the Sunday before, had contained small birds. We heard a 

 young grackle crying in distress, and on going toward the place from where the 

 noise came, saw a Purple Gallinule standing on the edge of the nest holding with 

 one foot a half-grown grackle while it deliberately tore at its back with its beak. 

 On our nearer approach, the gallinule took the still living young grackle in its 

 beak and flew with it about 75 yards to the pond's bank, where we watched it 

 tear it to pieces and eat it. It first tore a hole in the back of its victim, and pulling 

 out the viscera in sections, swallowed the pieces as they came free. It then 

 tore bits of tender flesh from the body, paying no attention to my approach in a 

 boat to within about sixty feet of it. 



Field marks. — Essentially similar to its eastern counterpart (see 

 p. 373), this race may be distinguished in the field by the iris, which 

 is dark brown, whereas it is yellow in the eastern one. 



DISTRIBUTION 



Range. — The Florida boat-tailed grackle breeds and is mainly 

 resident, but wandering in winter, along the shores of the Gulf of 

 Mexico from southeastern Texas (Galveston, Port Arthur), southern 

 Louisiana (Ged, Madisonville), southern Mississippi (Bay Saint 

 Louis, Deer Island), southern Alabama (Chuekvee Bay, Alabama 

 Port) to Florida (Bay County) ; south to the Florida Keys. 



Egg dates. — Florida: 41 records, March 3 to June 4; 24 records, 

 March 20 to April 16. 



Texas: 103 records, April 3 to June 9; 54 records, May 1 to May 22. 



