THE HOMING OF THE SALMON 37 



THE HOMING OF THE SALMON. 



By W. L. Calderwood, F.R.S.E., Inspector of Salmon Fisheries 

 to the Fishery Board for Scotland. 



The Salmon spends most of its life, and puts on its weight, 

 in the sea, but returns to fresh water, and can spawn only 

 in rivers and streams. It is usual to speak of the homing 

 of birds in a similar way, as a return to the former nesting 

 locality, and amongst birds, Swallows, Swifts, and many others 

 are known to acquire a wonderful precision in this return. 

 The trackless sea is to Salmon as the open air of continents 

 is to birds. The fact that the majority of the species related 

 closely to Salino saiar are exclusively marine need not con- 

 cern us for the present : Char in the Arctic are still migratory, 

 although British Char are now of purely fresh-water habit. 

 There is no real specific distinction between Sea Trout and 

 Brown Trout, but the former have adopted a migratory habit 

 and a changed general appearance in consequence. Spar- 

 lings and Shad come into brackish or fresh waters to spawn 

 and return immediately to the sea. The Salmon, in habit, 

 resembles several allied species ; it may spend many months 

 in fresh water before spawning and become almost a fresh- 

 water fish, it may migrate like a Sea Trout, or it may 

 behave as the Shad does. 



The cause of the first migration seems clearer in the 

 case of the Salmon than in that of birds. After hatching 

 and early life in the river it goes to the sea for the benefit 

 of securing more food. The land-locked Salmon of great 

 lakes in Sw^eden and America is a poor fish by comparison 

 with the migratory Salmon. If the thousands of Salmon, 

 Parr, and Smolts in our rivers did not go to the sea, we 

 probably would have no Trout in our Salmon rivers, since 

 the competition for the same food would be excessive ; and 

 when we reflect upon the very great numbers of spawning 

 fish which used to crowd into our streams, we can understand 

 the necessity for a vastly greater supply of food than our 

 rivers can yield, and the development of the sea\vard-m;igpa-^. ..}^C /\ 

 tion accordingly. />.."^V;-:^'''® ^<^\'1^4 



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