Some of the fish-eating birds, hovjover, do "pay their vicy^^ and render 

 valuable service from the purely utilitaric.n str.ndcrd. Franklin's gall, the 

 black tern, and to a lesser extent rel:.tod speci-^s breeding inland, are among 

 the most useful of the insectivorous birds. The beautiful sea-gull nonument 

 on Temple Square in Salt Lake City, Utah, erected at a cost of more than ^40,000 

 in grateful remembrance of the service of these birds to the early Utah pioneers 

 in delivering them from a cricket plague, is indeed a fitting tribute to the 

 California gull. Many fish- eaters also feed on predaceous insects and other 

 creatures that destroy the spavm and young of valuable fishes, . . 



Fish-eating birds within reasonable limits, therefore, provide values 

 that no country can afford to lose, despite the fact that they sometimes cause 

 annoyance to anglers or slight losses to conmercial fishenr.en. The appeal of 

 a colony of nesting birds, such as egrets or pelicans, for example, without 

 doubt has been a factor in attracting tourists to various parts of the country. 



Unjust Charges Against Birds ' ' . 



'It is well to bear in mind that, like most other creatures and within 

 the limits of their peculiar diet, fish-eating birds feed on '..'hat is most common 

 and most readily obtainable. Consequently they get as a rule only a small 

 proportion of game or commercial fishes, as, it usually is in relatively small 

 proportion that these fishes occur. The great majority of both the gwiQ fishes 

 and the' species of -greatest commercial value are also svjifter and often inhabit 

 deeper vjater than- other species, and consequently escape the fate of the slcv;er 

 surface feeders. In som.e trout streaiAS there may -be a preponderance of trout ' 

 over other fishes, yet ev-en here the birds frequently find and capture insects, 

 crustaceans, frogs, salaraanders, or snakes more easily than they can obtain the 

 .elusive trout. • . 



Condemnation is frequently directed against fish-eating birds because 

 large plantings of fingerlings or fry are made in certain streams v/here com-' 

 ^aratively few 'trout- are subsequently retrieved. A f ov; herons, kingfishers, 

 or terns m^ay appear as the only visible enemdes, and on this circumstantial 

 evidence the birds are convicted and summarily given capital punishment. The 

 facts should not be forgotten that a- scarcity of fish or a failujc in fish 

 production may result from a great variety of chemical, physical, and 

 iDiological conditions, important among which are excessive sedimentation, 

 insufficient dissolved oxygen, unfavorable temper at 'ores, pollution, scarcity 

 of food, cannibalism, predation by other fishos (often including the prized 

 game species) , and over-fishing. Since m.ost of these factors are not evident 

 to the casual observer, he is likely to conclude that the scarcity is due to 

 any object of his disapproval that seems conspicuous at the moment. Birds 

 arc thus frequently unjustly condemned. 



Frequently the worst' enemies of the young of economically valuable 

 fishes zxa the lajrger individuals of their own kind or others of similar 

 habits. I'Tith a series of stoniachs of. Arctic terns from Alaska, sent to the 

 Fish and Wildlife Service ' for .analysis, _wero six stomachs of trout. T-Diile 

 the contents of the former clearly showed that the birds had been feeding 

 on sm.all numbers- of the young trout, in this instance their depredation,.^ 

 "although conspicuous, was minor in comparison with the destruc-tion'being 

 wrought by the large cannibalistic trout. All six of the trout had fed 

 exclusively on young salmon, having 23, 22, 14, 14, 13, and 15 parrs, 

 respectively, in their stomachs. This threat to salmon parr was fully' 



