22 UNIVERSITY OF COLORADO. 



adult murres incline toward fish. A downy young loon was found with a 

 6-inch torn-cod in his gullet. Grebes are not so strongly addicted to a fish 

 diet as is generally supposed, the vegetable portion of their diet making them 

 good table birds (55). Two eared grebes examined by Aughey contained 14 

 grasshoppers, a few other insects, crayfish and part of a fish (56). Stomachs 

 of 57 horned grebes contained feathers up to 66%, but ignoring the feathers, 

 the balance consisted of beetles 23.3%, other insects nearly 12%, fishes 

 27.8%, crayfish 20.7%, other crustaceans 13.8%, and snails, spiders and vege- 

 tation in small amounts (57). 



LONGIPENNES- Gulls, Terns, Etc. 



Some of the gulls and terns are very useful, and probably all are prac- 

 tically harmless, on the whole. Most species of both feed largely upon 

 fishes, but also take many insects and other pests, especially those which 

 frequent the interior regions. Gulls are well known as scavengers about 

 harbors, and for that reason have been long protected by local laws. As 

 hereinbefore noted, gulls once saved Utah crops from crickets. Though 

 people insist upon calling all gulls "sea gulls," Franklin's gull frequents 

 inland lakes and marshes and often does much good. Ninety-three stomachs 

 from various places showed an average of 43% grasshoppers in their food, 

 many of the stomachs being filled with from 50 to 90 of these destructive 

 Insects. During mouse and lemming plagues gulls have been found feeding 

 extensively upon those rodents. Probably the ring-billed gull, common in 

 migration in Colorado, has similar habits. The black tern, our common one 

 in Colorado, feeds chiefly upon insects about 70% insects and 20% fish on 

 an average (58). Aughey, in his great work upon the food of Nebraska 

 birds, examined the stomachs of the pomarine jaeger and Franklin's, great 

 black-backed, herring, and ring-billed gulls, and found all to contain grass- 

 hoppers or locusts and other insects, with usually fish, frogs, crayfish and 

 mollusks, while the Forster's, arctic, least, and black terns were found to 

 be very highly insectivorous (59). 



TUBINARES- Albatrosses. Petrels, Etc. 



The albatrosses, fulmars, shearwaters, and petrels are marine, and have 

 no economic value to people living far in the interior of North America. 



STEGANOPODES- Boobies, Cormorants, Pelicans, Etc. 



Of this order, only the cormorants and pelicans visit the Southern Rocky 

 Mountain Region, a few of each passing through Colorado in migration. 

 Pelicans feed chiefly upon fishes, and cormorants take chiefly fishes and 

 crustaceans. They are not common enough in this region to be of any im- 

 portance. The anhinga, or water turkey, of the South, feeds chiefly upon 



(55) Judd, TJ. S. Dept. Agric., Yearbook for 1900, p. 433 ; U. S. Biol. Surv., Bull. 

 No. 17, p. 79. 



(56) Aughey, First Kept. TJ. S. Entom. Com.. App. II, p. 62. 



(57) McAtee and Deal, U. S. Dept. Agric., Farmers' Bull. No. 497, pp. 18-19. 



(58) McAtea and Beal, Farmers' Bull. No. 497. pp. 21-26. Lantz, U. S. Biol. 

 Surv., Bull. No. 31, p. 53. For Franklin's Gull see also Farmers' Bull. No. 513, p. 31. 



(59) Aughey, First Kept. U. S. Entom. Com., App. II, pp 60-62. 



