This section is from the book "The Balance Of Nature And Modern Conditions Of Cultivation", by George Abbey. Also available from Amazon: The Balance Of Nature And Modern Conditions Of Cultivation.
The Common Gull (Larus canus), Fig. 42, included in the family Laridae and sub-family Larinae or Gulls, is common on the coasts of the British Islands. It is distinguished by the straight bill, by the light body supported by large wings, by slender legs, palmated feet, and a small hind toe. It breeds in great numbers on the rocky coasts, or inland in moory districts. Its nest is composed of grass, rushes and other materials, and contains three or four eggs, of an olive-green marked with very dark brown.
Fig. 42. - The Common Gull.
The gulls are exceedingly voracious, fighting with each other for prey. They keep much on the wing, and, though swimming well, do not dive, but snatch up their prey when at or near the surface. They are patient of hunger, but will feed upon every kind of animal food, either dead or alive, putrid or fresh. Their principal food, however, is fish, but they also feed on mollusca, Crustacea, etc. Inland, the gulls, visiting the fields in autumn, winter, and spring to some distance from the coast, feed upon worms, frogs, mice (bolting them head foremost), cockchafer grubs, wireworms, beetles and other insects with their larvae and pupae. During the winter gulls frequent the estuaries of rivers, sometimes visiting shipping centres, such as London, and in presence of food abide until mild weather in early spring. Gulls are easily tamed, and always display the same quarrelsome and voracious habits as on their native coasts. The other gulls are of similar habits to the common gull, but particular note may be made of the.
Black-headed Gull (Lams ridibundus), Fig. 120, as affecting the farming and fisheries in the north of England, particularly Cumberland, where its food consists of vegetable and animal matter considered neutral in nature. "Of 100 birds examined 40 contained food which would lead the bird to be classed as 'harmful,' e.g. fishes, cereals, useful insects; 47 contained 'beneficial' food, e.g. injurious insects and mollusca, carrion, and waste animal matter; and 82 contained 'neutral' food, e.g., earthworms, Crustacea, and spiders, harmless insects and mollusca, and vegetable matter other than cereals" (The Journal of the Board of Agriculture, Vol. XIV., No. 7, p. 111). Earthworms appear the staple food of the black-headed gull in inland districts, though wire worms, leather-jackets, common slugs, beetles and flies - injurious, harmless, and beneficial - are taken indiscriminately. Fish is sparingly eaten, partly from want of opportunity, as the black-headed gull does not readily obtain fish from water more than a few inches in depth, and partly from the greater ease with which other food can be procured at most seasons of the year. But gulls, like most other creatures, acquire new habits under abnormal increase, and then become injurious to the farming and fishing interests.
Worms and other invertebrate animal food may suffice under no shortage of supply, but directly there is a deficiency of this class of food the gulls become addicted to the taking of grain (oats) and other vegetable produce, and to capturing and eating fish.