14 THE ESSEX NATURALIST
an angler, which had just seized a great northern diver. There
is not much evidence from British waters of cod destroying birds
but coupled with information from across the Atlantic it suggests
that this fish is no mean enemy of avian life. In March, 1879,
at Wick a black guillemot, stated to be in perfect condition,
was removed from the stomach of a cod. The same recorder
writes that an entire partridge was taken from the stomach of
another cod. I know of only one instance of the monk- or
angel-fish, which may reach a length of 8ft., attacking birds, but
the account is given in detail. In July, 1881, some fishermen of
Anstey's Cove, near Torquay, noticed a commotion on the surface
of the water. A closer inspection revealed the wing of a cor-
morant protruding above the water and flapping vigorously.
It was evident that the bird was held down by something, from
which it was trying to escape ; this, on gaffing, turned out to be
a monk- or angel-fish. The fish was almost a yard long and
grasped the cormorant by a wing. The fishermen brought them
both ashore and made some money by exhibiting them. It
would not be so surprising to learn that the thresher, a shark
which may reach a length of 15ft., preyed on birds, but I know
of only one instance: Mr. H. Blake-Knox, an experienced
naturalist, in the winter of 1865 saw one rise and kill a wounded
diver, species not stated, in Dublin Bay, with a stroke of its
tail and then swallow it.
This account of the destruction of birds by fishes would be
incomplete without a consideration of the evidence from other
parts of the world, especially from North America, where in-
vestigations have been made for economic purposes. The pike
bears much the same character on the other side of the Atlantic
as it does here. The ornithological importance of the combined
Saskatchewan and Athabasca deltas will be realised when it is
stated that the average annual duck population between 1936
and 1941 was about 141/2 million birds. In this area it is stated
that crows, magpies and other waterfowl predators are almost
unknown. In the summers of 1940 and 1941 the relations of
pike and waterfowl were studied in this area by Mr. V. E. F.
Solman. A total of 3,001 pike was examined and it was found
that no young waterfowl had been eaten by pike under 14 inches
in length; the number of pike examined which had eaten young
waterfowl or which were large enough to do so—those between
19 and 30 inches long—was 2,658. Of this number 29, or 1.08
per cent, had eaten young ducklings and five, or 0.20 per cent,
young coots and grebes. A number of the pike contained more
than one young waterfowl; one contained four. The results
of the enquiry served to show that diving ducks suffered much
more than surface-feeders and that even among the former