14 
MUSEUM BULLETIN NO. 13. 
haunting species will generally neglect freeswimmers and only cap- 
ture occasional individuals that accident brings to their attention, 
nor will they without good reason neglect an abundant, easily 
captured food supply for a scarcer and more agile prey. The 
salmon at all stages is a free swimming fish, very agile and quick 
in its movements. The sculpin, on the other hand, is a ground 
feeder, hugging the muddy bottom, and is more easily caught 
than strong swimming salmon; therefore, so long as the former 
are present in numbers, the latter are not likely to be hunted 
or pursued extensively. The fact that the birds we obtained 
from the sculpinless reaches of the river near the mouth had 
empty stomachs, supports the view that salmon are difficult 
of capture. The one bird that we know had been fishing in salmon 
waters without results for an hour and a half further corroborates 
this view. 
From all reports, the salmon in the rivers have been lately 
increasing from year to year. One experienced man says that 
ten or twelve years ago about thirty fish were taken in the 
York river per year, while in 1913 from 120 to 130 were caught 
by anglers. The cormorants are also generally increasing in 
number, the rookeries are enlarging and new ones being estab- 
lished. These facts taken together do not indicate that the 
cormorants are markedly harmful to the salmon. In fact, they 
may be more beneficial than harmful as a whole, in helping to 
weed out the weak and unfit fish, and so keeping the stock up to 
virile strength. The danger of removing all predacious in- 
fluences was well shown by the grouse plague in Scotland when it 
was decided, by the investigating committee, that the great 
spread of the disease was due to the destruction of the vermin 
that normally, quickly, eradicated diseased or weakly birds before 
they had a chance to contaminate the remainder of the flock. 
From the evidence on hand it is, therefore, evident that the 
cormorants in the fresh water reaches of the rivers are few; that 
those in the tidal mouths feed on bottom haunting fish, and that 
as a whole the influence of cormorants upon the number of salmon 
can be disregarded as too slight to be of economic importance. 
