104 BULLETIN 195, UNITED STATES NATIONAL MUSEUM 



many enemies for the dipper among sportsmen and especially among 

 the managers of fi.sh hatcheries. The damage done to wild salmon and 

 trout by this bird is probably not serious under natural conditions, for 

 these fish are known to lay vastly more eggs than can ever hatch, many 

 eggs eaten by the dipper are known to be infertile, and vastly more 

 fry are hatched than can possibly survive ; I have seen it estimated that, 

 if all fish eggs hatched and the fry grew to maturity, the oceans would 

 soon be packed solid full of fish. Furthermore, the spawning grounds 

 of both salmon and trout are mainly in waters not often frequented 

 by the dippers, as these birds live mainly on the rapid mountain streams 

 rather than on the slower valley streams and spawning grounds where 

 they are rarely seen. 



Under the artificial conditions prevailing at fish hatcheries, it is a 

 different story; here the dippers undoubtedly do considerable damage. 

 J. A. Munro (1924) made a study of the relation of the dipper to fish- 

 ing interests in British Columbia and Alberta ; I ofi'er a few quotations 

 from his report. The manager of the Skeena River hatchery offered 

 the suggestion that "if naturally it eats a few salmon fry and ova, it 

 will balance this by eating ova and fry of the salmon enemies." The 

 Banff hatchery reported that "during the winter of 1921-22 not less 

 than 10,000 advanced Cut-Throat trout fry were taken from the ponds 

 and destroyed by these birds." In summing up all the evidence that 

 he gathered, Mr. Munro said that "it will be noted that little evidence 

 has been presented in reference to their consumption of sjoawn and this 

 is evidently not considered .serious by the fishery officials. * * * The 

 destruction of fry is perhaps a more serious offence but we have little 

 evidence that this takes place to an alarming degree under natural con- 

 ditions, the complaints having reference to the destruction of arti- 

 ficially propagated fry after they have been placed in the retaining 

 ponds. It has been noted that these small fish swim continually along 

 the shores of the ponds, seeking an outlet perhaps, and so fall an easy 

 prey to Dippers, Kingfishers or other birds that may be attracted to 

 this bountiful supply of food. * * * The practice of shooting these 

 birds in order to protect the fry has not had the desired effect," as new 

 birds come in to take the places of those that are shot. "The obvious 

 remedy is to .screen the surface of retaining ponds with fine mesh wire 

 netting. This will adequately protect the fry and render it unneces- 

 sary to destroy a song bird of high aesthetic value." 



A. Dawes DuBois writes to me : "Mr. Baigrie Sutherland, then forest 

 ranger in the Flathead National Forest for the district having its 

 ranger station at Belton on the Middle Fork of the Flathead River, 

 told me on the 24th of August, 1915, that he saw a water ouzel eating 

 fish offal which he had thrown into the edge of the water." 



Behavior. — It is indeed strange that a land bird, a song bird, and 

 one so closely related to the wrens and the thrushes should adopt so 



