opportunity permits, and often illegally — "control" of all such species. The 

 general food tendencies of these birds are somewhat similar to these of the 

 other members of their family, already described. Hithin limits all these 

 birds take -:hat is coi!imon and easy to get. Most of them feed primarily on 

 fishes, but not largely upon game species, and often upon the enemy and com- 

 petitor varieties — species that frequently constitute a major obstacle to 

 restocking operations. 



Gulls and Tern s 



The gulls and terns represent the family of fish-eating birds most 

 numerous in species and they frequent both inland and coastal vjaters. As 

 previously indicated, Franlclin's gull, the black tern, and other inland 

 species are among the most valuable destroyers of insects in agricultural 

 sectioxis. The value of- gulls as scavengers around harbors and commercial 

 fishery stations is too well known to need further comment, A study of the 

 foods of all the species occurring in the United States reveals that valuable 

 fishes form a minor part of their diet and that all of them are worthy of 

 protection, except vjhen overly abundant or under very localized and unusual 

 conditions, such as v;here a few species, including the herring gall, may 

 occasionally become a menace to shell-fish beds, blueberry plantations, and 

 rarely to the lobster industry. Considering the widespread abundance of this 

 large group of birds, complaints from fish-hatchery workers against their 

 depredations have been rare. 



Water Ouzel, or Dipper 



Some condemn, even vigorously, the delightful and fascinating little 

 water' ouzel, or dipper, of western m.ountain streams as an important destroyer 

 of sporting fishes. While it has occasionally been knovm'to feed on the small 

 fry and ova of trout and saLmon in hatchery ponds, it should be remembered 

 that this bird is smaller than a robin, is solitary in its habits, and rarely 

 can be considered abundant. Under natural conditions its destruction of fish 

 is trivial. This blithe water sprits is an exquisite songster and sings even 

 in the dead of w inter when few of nature's feathered progeny are present to 

 add a cheering note. He must be cold indeed who m.easures nature and her worth 

 only by rod or reel. The Fish and Wildlife Service has examined 60 stomachs 

 of this interesting bird and has found that it subsists largely on aquatic in- 

 sects, maaiy of which are enemies of young fishes. In this series of ouzels, 

 six had fed on small fishes, four of which (sculpins and a sucker) were of 

 species knov;n to feed on spawn, one was unidentifiable, and only one was a 

 valuable game' fish — a trout. VJhile no fish eggs were found in. any of the 

 stomachs, it is probable that small nmnbers are sometim.es taken. 



Osprey,. or Fish Ka'wk " ' . 



Another bird that oc.casionally preys on larger fishes in hatchery ponds, 

 but rarely takes valuable game species under natural' 'Conditions, is that mas- 

 ter of flight, the osprey, or fish hawk. Forty-three of these birds', collected 

 in 14 States, the District of Golujiibia, and 2 Canadian Provinces, representing 

 every month from April to October, vjere examined in the laboratory. Sluggish 

 fishes formed the bulk of their diet and only one contained an important game 

 fish— a trout. Suckers and menhaden formed by far the most important single 



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