476 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



comparative description of normal adults and hybrid and then com- 

 ments as follows: 



It is of course well known that in the Tree Swallow both birds of the year and 

 adults moult before leaving us for the South while the Cliff Swallow migrates 

 before moulting. It is consequently of interest to observe that in this hybrid 

 moult has begun normally with the innermost primaries. 



This fact is also of importance in determining the bird's age and, in con- 

 nection with the unworn condition of the wing-feathers, it leaves no doubt that 

 the specimen is in post-natal plumage. 



The radical differences in the character of the nests of the supposed parents 

 of this bird lead one to speculate on the type of nest-structure in which it was 

 reared, but, unfortunately, our curiosity in this direction cannot be gratified. 



Food. — Beal (1918) has reported on the examination of the stom- 

 ach contents of 375 swallows taken in every month from March to 

 September. The food consisted almost entirely of animal matter; 

 the small amount of vegetable matter (0.66 percent) was taken acci- 

 dentally with food. However, two stomachs of birds taken in May 

 in Texas were entirely filled with the fruit of Jvmiperus monosperirm^ 

 which was undoubtedly taken intentionally as food. 



The animal food consists of insects with a few spiders. The 

 insects consisted of beetles (26.88 percent), and of these members 

 of the May-beetle family, chiefly the small dung beetles, which are 

 easily taken on the wing as they fly in swarms near the ground, are 

 important. Snout beetles or weevils, including the destructive cot- 

 ton-boll weevil, were taken every month in large quantities, but in 

 September weevils constituted 50 percent of the food. Thirty-five 

 cliff swallows collected in the vicinity of cotton fields in Texas con- 

 tained 687 boll weevils, an average of 19 to each stomach. Besides 

 those mentioned above Beal found many other beetles, representing 

 113 species, in the stomach contents of the 375 cliff swallows. McAtee 

 (1926) found the chestnut, chinquapin, and acorn weevils of the 

 genus Balanimus and also Ops pinus, a special enemy of the white 

 pine, during his special studies of the relation of birds to woodlots 

 in New York State. 



Beal found that ants, mostly winged forms, were eaten evei*y 

 month except March. Other Hymenoptera eaten were wild bees and 

 wasps and some parasitic species. The remains of 35 honeybees 

 {Apis mellifera) were identified in 13 stomachs. 



Hemiptera comprised 26.23 percent of the food, the most impor- 

 tant representative being the well-known and harmful chinch bug 

 {Blissus leucopterus) . 



Diptera comprised 13.95 percent. Green flesh flies were present in 

 large numbers, but crane flies, which are eaten by other swallows, 

 were not found in the stomachs of the cliff swallows. 



