November 1, 1899.] 



KNOWLEDGE 



255 



day during the winter. Following this up with a calcula- 

 tion of the number of birds to the square mile, it works 

 out that one million seven hundred and fifty thousand 

 pounds, or eight hundred and seventy-five tons, of weed 

 seeds are destroyed in a single winter in the State of Iowa 

 alone. 



Another direct piece of evidence in favour of the useful- 

 ness of birds was obtained on a farm in Maryland. Here, 

 in December, a number of sparrows of species whose 

 common names we have already mentioned, together with 

 juncos (Junco hyemalis). fox sparrows {Pnsserilla iliura), 

 and whitethroats occurred in positive swarms. They paid 

 particular attention, when feeding, to the tangles of smart- 

 weed, and towards the Spring the ground under a particular 

 thicket, some three feet high, wag examined. The surface 

 of the soil was quite black with seeds, but these were 

 found to have been split open and emptied of their con- 

 tents. In a patch eighteen inches square, one thousand 

 one hundred and thirty half-seeds were obtained, but only 

 two whole ones had escaped the birds. 



Summing up the matter, it may be said that some 

 fifty species of birds help in destroying the seeds of more 

 than sixty kinds of weeds. Among these are reckoned the 

 blackbirds and their allies as a set-oft' to their grain-stealing 

 habits. The palm is given to the numerous species included 

 under the heading of sparrows, who, Dr. .Tudd says, " are 

 little weeders whose work is seldom noted but always 

 felt." 



Another paper of interest, dealing with the dangers of 

 introducing noxious animals (mammals) and birds, is by 

 Mr. T. S. Palmer, also of the Biological Survey. Here it 

 is laid down that sometimes the acclimatization of animals 

 has not been followed by such useful results, ultimately, 

 as that of plants, for as a rule the latter are for cultivation, 

 and, consequently, kept within bounds, whereas the animals 

 are set free under conditions that are the nearest possible 

 to their natural environment. Occasionally a garden plant 

 may " escape " and multiply until it is reckoned an 

 objectionable weed, or a wild one may accidentally become 

 introduced with the same result, but the rule holds good. 

 How even a valuable domestic animal may run wild, and 

 cause serious damage, is illustrated by the case of the 

 horse in Australia and the Western States of America. 

 Indeed, in 1897, a law was passed in Nevada to authorize 

 the shooting of wild horses. 



The way in which the goats, introduced into the 

 beautifully wooded island of St. Helena in 1513, had 

 converted it into a howling wilderness by 1810, carries 

 with it the mournful remembrance of plants and the 

 animals dependent upon them reduced to extinction that 

 no naturalist likes to dwell upon. We will only mention 

 that it costs the Government some £3000 a year to import 

 fuel for their own use. The introduction of carnivorous 

 animals like cats directly kills off many forms that are not 

 prepared for such an attack in places like oceanic islands 

 where there is no escape. 



Next we are given an intei-esting history of the invasion 

 of the common brown rat, with the dates of its introduction 

 into various countries. Its original habitat is said, upon 

 the authority of Dr. Blandford, to be Chinese Mongolia. 

 The case of the rabbits at the Antipodes is too well known 

 for us to dwell upon, but it might be worth while considering 

 the remedy, which seems to be worse than the evil. Ferrets 

 have been liberated in thousands, together with weasels 

 and stoats, to keep the numbers of the rabbits down, but 

 the two wild species in particular have not confined their 

 attentions to the rodents, but have diminished the nu-.nber 

 of game birds, and brought many of the interesting local 

 birds to the verge of extinction. 



A similar state of aflEairs has resulted from the turning 

 out of the mongoose in .Jamaica to exterminate the rats 

 infesting and damaging the sugar-cane crops. In 1872, 

 four males and five females were imported. In 1882 the 

 saving to the sugar planters was estimated at forty-five 

 thousand pounds. As the rats became scarcer a sad state 

 of affairs liegan to come to pass. Domesticated animals, 

 particularly yoimg ones, were destroyed conthiually, the 

 native mannnals and birds, as well as snakes, lizards, and 

 other insect-eating creatures, fell a prey to the mongooses, 

 and by-and-by a plague of ticks and swarms of noxious 

 insects filled the island. Even fruits did not escape being 

 eaten by the mongooses when animal food failed. At the 

 present lime, however, the carnivorous foreigners are less 

 numerous, but greater loss by far resulted from their 

 acclimatization than if they had never been brought to 

 stay the ravages of the rats. 



In the Hawaiian Islands the same beast did much tin; 

 same things, and when an unfounded rumour of its pro- 

 posed introduction into the United States by the Depart- 

 ment of Agriculture got about, many who knew its history 

 elsewhere raised a great outcry, while others in ignorance 

 made arrangements for the introduction of specimens 

 which through strcimous efforts was prevented from bei^'g 

 carried out. Stringent measures of recent years have 

 alone prevented the importation into California of the 

 fruit-eating bat, or flying fox, which is one of the greatest 

 pests of the fruit growers, and threate)is their industry 

 with destruction in a great part of Australia. There 

 seems to be consideralile danger of the creature getting a 

 hold in the Sandwich Islands,if the matter lie not cnrefully 

 looked after. 



Coming to birds, Mr. Palmer gives a map showing the 

 distribution of the English sjjarrow in the United States, 

 and the colonies it had formed in 1860, 1870, and 188G, 

 from which it has still further spread. The old crimes of 

 damaging fruit and grain, of becoming a nuisance in cities, 

 and replacing native birds, are laid once more at its door, 

 without any redeeming features such as were given in the 

 paper previously considered. Its marvellous adaptability 

 is shown by the number of places throughout the world 

 where the sparrow is now established. 



The starling has to be given the credit of destroying 

 insects in this country, but with change of scene comes 

 change of habits, and in New Zealand we find our friend 

 with omnivorous rather than hiseotivorous propensities. 

 The Government of New South Wales, after careful 

 consideration, came to the conclusion to prohibit the 

 importation of starlings into their territory, as they have 

 done that of other creatures harmful to the agriculturalist, 

 by means of a special law. 



A contrast is drawn betwecii this arrangement and the 

 unrestricted introduction of all forms of life into the United 

 States. We see, too, from the paper under discussion, as 

 well as from others in the year-book, how quickly attention 

 is turned by the various divisions to the possibilities of the 

 new possessions of America, and again it is emphasized that 

 the mongoose must not be allowed to reach the mainland 

 from Hawaii or Puerto Piico, nor must the h'uit-eating bat 

 be permitted to obtain an entry into the first of these 

 places from Australia. 



Iloticcs of Boofes. 



.1 List of British Birds l)elo)i()mii to the TTuiithef Dislrict. 

 By John Cordeaux, .r.i'., F.R.d.s., M.B.o.U. (Porter.) 2s. fid. 

 net. Just before his much lainenteJ death Mr. Cordeaux 

 published the above list of the birds of his district. This 

 district, which may be roughl}' described as the land and sea 



