THE DOUBLE-CRESTED CORMORANT. 13 



propagation duties are over, both sexes are thin, worn, and unfit 

 for human food. In this condition they pass down stream under 

 the name of kelts to be rejuvenated in salt water and made 

 ready for successive breeding migrations in following years. It 

 seems to be yet an open question as to whether the kelt feeds 

 in fresh water. General opinion indicates that they may do so, 

 but definite data on the subject are difficult to obtain. If they 

 do it must be at the expense of their own race the parr, smolt, 

 and perhaps grilse. It is evident, then, that the salmon have to 

 run the gauntlet of their enemies in the estuaries once as smolts, 

 twice as grilse, and again annually as long as they breed as 

 salmon and kelt. The grilse are large enough to be practically 

 safe from attack by cormorants except, possibly, the smallest and 

 weakest whose weeding out is beneficial to the race. The salmon 

 and kelt are obviously beyond danger from birds. There 

 remains then, only the parr and smolt that have anything to 

 fear from cormorants and these only as they are making the 

 passage from fresh into salt water. The work has shown that 

 during July and August either there are no smolt in the tidal 

 mouths of the rivers or else the cormorants do not catch them. 

 Though it is difficult to get exact data on the subject it seems, 

 from the information at hand, that the journeying of the smolt 

 to the sea is not accomplished in one general migratory move- 

 ment but that they drift out continually during the summer 

 months and that July and August conditions are fairly typical 

 of the whole spring and summer season. If this is correct, the 

 cormorants must be acquitted of any serious injury to salmon; 

 if it is not, evidence to the contrary must be submitted. The 

 food eaten by any species is governed largely, within certain more 

 or less widely defined lines, by its availability. Cormorants 

 probably eat practically any small fish they can catch, but any 

 hunter knows that only one kind of game can be successfully 

 hunted at a time: the hunter after deer rarely sees birds; the 

 collector of ground birds misses the species over-head, and so on. 

 Concentration in one direction blinds us to what is happening 

 elsewhere. Occasionally the unlocked for does appear; but it 

 is generally more or less of an accident and does not negative 

 the foregoing rule. Hence creatures of prey hunting for bottom 



