272 Birds Every Child Should Know 



birds and their exquisite little cousins, the 

 terns or sea-swallows, had been slaughtered. 

 Then some people said the massacre must stop 

 and happily the law now says so too. Paid keep- 

 ers patrol some of the islands where gulls and 

 terns nest, which is the reason why you may see 

 ashy-brown yotmg gulls in almost every flock. 

 When they mature, a deep-pearl mantle covers 

 their backs and wings, and their breasts, heads 

 and tails become snowy white. Their colour- 

 ing now suggests fogs and white-capped waves. 

 Why protect birds that are not fit for food 

 and that kill no mice nor insects in the farmer's 

 fields? is often asked. A wise man once said 

 *'the beautiful is as useful as the useful," but 

 the picturesque gulls are not preserved merely 

 to enliven marine pictures and to please the eye 

 of travellers. They fill the valuable office of 

 scavengers of the sea. Lobsters and crabs, 

 among many other creatures under the ocean, 

 gulls, terns and petrels, among many creatiu-es 

 over it, do for the water what the turkey buz- 

 zard does for the land — rid it of enormous 

 quantities of refuse. When one watches hun- 

 dreds of gulls following the garbage scows out 

 of New York harbour, or sailing in the wake of an 

 ocean liner a thousand miles or more away 

 from land, to pick up the refuse thrown over- 

 board from the ship's kitchen, one realises the 

 excellence of Dame Nature's housecleaning. 



