106 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 

 THE SKYLARK, GREEN LINNET, AND BLACK THRUSH. 



The skylark {Alnwla arvensis), the green linnet {Licjurinus cMoris), 

 and l)lack thrnsli, or black bird (Turdus merula), are all natives of 

 Europe. They are chiefly of interest in this connection, because in 

 their native home they are almost universally considered beneficial, 

 but in New Zealand they have developed traits which render them 

 far I roiii desirable additions to the fauna of that island. They were 

 introduced into New Zealand in 1807; in 1870 they had begun to breed 

 in a wild state in the province of Auckland on the North Island, and 

 the green linnet was reported as already becoming common.^ At the 

 present time the}^ are common all over the colony and troublesome in 

 certain districts. The skylark confines its injuries mainly to turnips, 

 eating the seed soon after it is planted, and thus causing no small 

 damage to the future crop. The green linnet is similarly injurious to 

 grain, while the black thrush is accused of taking strawberries, cur- 

 lants, raspberries, and other small fruits. As a fruit destroyer the 

 black thrush is said to be worse than the English sparrow, and the pro- 

 jjosal to inti'oduee it into Western Australia elicited a strenuous protest. 



The skylark has been introduced several times into the United 



States, especially in the vicinity of New York, and recently all three 



birds have been liberated in Oregon, but as yet they have not increased 



to any extent. Both the skylark and the black thrush are noted 



singei's, but the charms of their song hardlj^ compensate for damage 



to crops. 



NEED OF LEGISLATION. 



The examples already cited show the danger of introducing exotic 

 species on large islands, particulai-ly on those far distant from con- 

 tinents, where the fauna is necessarily limited and predatory species 

 practically absent. In such places introduced species are almost 

 sure to increase very rapidl}^ The experience of New Zealand indi- 

 cates the necessity of exercising unusual care in introducing birds 

 and mammals into the islands recently ac(iuired by the United States. 

 Much remains to be learned about the fauna of these new possessions. 

 Puerto Rico is less known than any of the larger islands of the West 

 Indies, but it probably has no indigenous nuimmals except bats. 

 About 150 species of bii-ds have been recorded from the island,^ 

 of which 20 are not found elsewhere. The fauna of the Hawaiian 

 Islands is still more limited; indigenous nuimmals, except one bat 

 (L(i.siurus), iivQ entii-ely wanting, but numy of the birds are of great 

 interest. Although no complete list of them has yet been luiblished, 

 about lOU species are known to occur on the islands. The fauna of 



' The green linnet has found its way to the Kermadec Islands, fiOO miles to the 

 northeast, and all three si)ecies are said to be now present on the Chatham 

 Islands, nearly 500 miles east of the South Island of New Zealand. 



-aundlach. J. F. ()., XXVI, 1878, p. 1G3. 



