360 U. S. NATIONAL MUSEUM BULLETIN 211 



examined contained one egg each that did not hatch, and three out of 

 nineteen * * * contained two." He also found that in the first 

 nesting there were no infertile eggs, in the second an occasional one, 

 while in the third, "the majority of nests contained one or more 

 infertile eggs." It may be that the unique breeding habits of the 

 male are reflected in this manner, or perhaps these are examples of 

 lowered vitality, decreased virility, and the like. 



Plumages. — The comments given in our account of the eastern race 

 of this species apply to this one as well (see p. 368). 



Food. — In his full and interesting study of the boat-tail in Louisiana, 

 E. A. Mcllhenny (1937) notes that the food supplied to the young 

 "varies considerably. On some days it is almost exclusively small fish; 

 on other da}^s it may be spiders, and on still other days almost entirely 

 crickets, grasshoppers or other insects. * * * Then again, when a 

 batch of dragon-flies (either Libellula or Diplax) is coming off, the food 

 supply consists entirely of dragonfly nymphs. On other days, if tad- 

 poles or small frogs are especially abundant, these will constitute the 

 food for the young. The Cricket Frog (Acris crepitans) is the one most 

 used. I have not seen seed or grain or plant food fed to the young." 

 He adds that caterpillars are taken now and then by boat-tails, which 

 in so doing perform a distinct service to agriculture. He says: "Fre- 

 quently, in the autumn, fields of soybeans may be infested by great 

 numbers of caterpillars which sometimes destroy the entire bean crop. 

 When the Boat-tails find such an infestation they flock to these fields 

 in enormous numbers and do not leave them until all caterpillars are 

 eaten." Thus, while some of the bird's food habits may not seem to be 

 of marked benefit to man's interests, this, at least, certainly is, and so 

 is the bird's destruction of such insects as crickets and grasshoppers. 



Behavior. — Like the eastern race, this boat-tailed grackle stays 

 fairly close to water. It goes further inland from the coasts, wherever 

 streams or ponds occur, but the only area where it really penetrates 

 far into the interior seems to be in Florida. Occurring on both coasts, 

 the birds are scattered across and through the Peninsula, and one finds 

 it wherever there is any swampy or river-lake habitat. However, it 

 is very much of a city bird as well as rural, and is found breeding in 

 Jacksonville, as well as at practically every small farm on the east coast 

 of Florida. In its tendency to feed and to spend most of its time on the 

 ground this bird is also like its eastern counterpart. It is at times 

 predatory, not only attacking other birds but even on occasion prac- 

 ticing cannibalism. 



Interesting instances of preying on other birds are given by E. A. 

 Mcllhenny (1937), who states that the first instance he witnessed oc- 

 curred in 1911, while he was in the company of George Bird Grinnell, 

 on the coast of Louisiana. "We were in my big launch," he says, 



