BIRDS AS THE FOOD OF FISHES 15
group some species seemed to be more susceptible to attack
than others. It would appear that no evidence was found of
adult waterfowl having been taken by pike. Female pike were
responsible for 56 per cent of the casualties although they com-
prised only 47.8 per cent of the population. Mr. Solman points
out that pike may destroy 9.7 per cent of the average annual
production of waterfowl in this area.
Although so far as I know, the pike is the only fish which has
had such an investigation devoted to it, there is a certain amount
of information from abroad regarding other fishes, particularly
the angler. E. W. Gudger records that a large angler was taken
in Raritan Bay, New Jersey, on 18th November, 1928, with a
good-sized sea-gull stuck in its throat. The bird had been
asleep when captured. Among the birds which are included
as the prey of this fish in American waters are great northern
diver, cormorant, herring-gull, widgeon, scoter, guillemot, razor-
bill, grebe, scaup-duck and merganser. On one occasion seven
wild ducks were taken from the stomach of an angler. The cod
may not be so formidable an enemy as the angler, but it has been
recently recorded that paroquet auklets, guillemots and even
cormorants have been taken from the stomachs of cod in Alaskan
waters.
As further instances of fresh water fishes preying on birds
may be mentioned Hydrocyon and the piranha. The former is a
genus of large ferocious carnivorous fishes inhabiting the African
lakes from the Nile to the Congo and Limpopo. A. L. Butler
describes how this fish preys on the gorgeously coloured Soudanese
red-throated bee-eater, along the Rahad and Dinder Rivers;
he noticed that the fish were rising at the bee-eaters every time
they skimmed the surface of the water. As a rule the birds
easily avoided the fish by shooting straight up into the air, but
during half-an-hour's observation he saw two taken like flies
within a few yards of him. In Brazil the piranha is known to
tear to pieces wounded wild fowl.
Although it is only recently that attention has been given to
the menace to birds from fishes, it was not unknown to early
writers, for Izaak Walton (The Compleat Angler, 1653, p. 145)
states that Gesner affirmed that a Polonian gentleman had
faithfully assured him that he had seen two young geese at one
time in the belly of a pike. Gesner wrote a hundred years earlier
than Walton.
The evidence presented demonstrates clearly that some fishes
are terrible enemies of birds, especially aquatic ones. We must
bear in mind how very difficult it is to get the necessary proof;
for every instance discovered many must remain unnoticed.
This is an approach to the study of bird-life which has not