CHUCK-WILL'S-WIDOW 153 



fields and often makes sallies over the latter. The flight is silent, and 

 the birds seem to be no more than gigantic moths. Beetles, "flying 

 ants," and moths make up a large bulk of the food in many localities. 

 Small birds have frequently been found in the stomachs of this spe- 

 cies. While seemingly incongruous, this is, after all, not difficult to 

 understand when the conditions are considered. Many observers have 

 concluded that this type of stomach content is taken by mistake ; that 

 the small, fluttering bird, confused by the darkness, is taken for a 

 moth and snapped up by the cruising chuck, of course being swallowed 

 whole. 



An alternative theory exists, however, and, if true, the bird-taking 

 habit would be removed from the realm of the accidental and fall 

 into purposeful, predatory effort. The late Edward H. Forbush 

 pointed out that the "goatsuckers show an anatomical affinity to the 

 owls. They have similar, soft plumage, noiseless flight, large eyes 

 and nocturnal vision." It is possible that, with this structural re- 

 lationship, there are other phases of likeness between the chuck and 

 the owls. It is the largest of the goatsuckers that occur in this 

 country, and the other representatives of the family do not seem to 

 indulge in small bird prey. Doubtless this is because of their con- 

 siderably smaller mouths, but whatever the reason the chuck remains 

 as the outstanding example of this procedure. 



That this habit is certainly not accidental sometimes is definitely 

 proved by the observation recorded by Gerald Thayer (1899) in 

 which he relates the instance of a chuck-will's-widow pursuing and 

 catching warblers near a ship off the Carolina coast. Hummingbirds, 

 swallows, sparrows, and warblers have been among those birds found 

 in the stomachs of the chuck, and the frequency with which this 

 occurs lends color to the supposition that it is more intentional than 

 accidental. More research is necessary on this subject. 



Even granting the truth of it, the economic status of the chuck is 

 on the right side of the ledger and the great percentage of its activi- 

 ties are beneficial, for the noxious insects which it destroys are 

 numerous. Miss Phoebe Knappen, of the United States Biological 

 Survey, in answer to a request of the writer has very kindly furnished 

 a summary of specific results in the stomach analysis carried out on 

 this species in the laboratories of that Bureau. A full stomach from 

 Oklahoma, without date and therefore not included in the tabulation 

 below, contained the following: Dendroica (sp.), 70 percent; Coleop- 

 tera {Galasoma, Harpalus, Carabidae, Ligyrus, Strategus, Scarabaei- 

 dae), 22 percent; Orthoptera {Schistocerca, N esconocephalus) ^ 8 

 percent. 



The remarkable percentage of bird remains shown by this stomach 

 would seem a great argument for the support of predation by purpose. 



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