Maintaining the Balance of Life. 



107 



furnish his table two or three days a week. 

 But their introduction into New Zealand 

 is by no means regarded as a blessing, now 

 that experience has shown not only that 

 they are easily acclimatized in that country, 

 but that in the absence of ferrets, stoats, 

 weasels, polecats, foxes, or other predaceous 

 animals suited to maintain the balance of 

 life by increasing numerically with their 

 means of subsistence, the law of geometri- 

 cal progressions holds as good for rabbits as 

 for horses, only in an enormously higher 

 ratio. Under favorable conditions, that is to 

 say with ample food supply and no foes, a 

 pair of rabbits will multiply four fold in one 

 year, at which rate a single pair would in- 

 crease to two millions in ten years, and to 

 two thousand millions in fifteen years. 



By shooting and trapping, these figures 

 are being to some extent modified, but al- 

 though man is more than a match for horses 

 or tigers, he cannot spread himself out in 

 the ratio of the geometrical progression of 

 rabbits, nor cope with them unaided. 



If along with each hundred pair of rab- 

 bits the New Zealand squatters had turned 

 loose a pair of ferrets or polecats, the former 

 would never have become a national pest, 

 as they now admittedly are. They are 

 rapidly tending to become the "bloated 

 monopolists " of New Zealand, and the soon- 

 er the colonists give their attention to the 

 acclimatization of polecats, ferrets and other 

 animals of that class, the better for the well- 

 being of the colony. 



Some years after the establishment of 

 rabbits in New Zealand, and before they 

 were recognized as a danger to the agricul- 

 tural future of that country, the Queensland 

 farmers introduced them into their colony. 

 The conditions are by no means the same, 

 for although Queensland has no ferrets or 

 minks or animals of that genus, it has the 

 dingo or wild dog, and innumerable snakes 

 large enough to prey on rabbits, so that al- 

 though rabbits cannot possibly monopolize 

 the country as they are doing in New Zea- 



land, the balance of life will be obtained by 

 a very undesirable increase in snakes and 

 wild dogs. 



This result has not been foreseen in the 

 colonies; the one anxiety is lest the rab- 

 bits should overrun Australia as they are 

 overrunning New Zealand, and an enormous 

 outlay for close wire fencing is being incur- 

 red to confine the danger to Queensland, 

 but it may be predicted with confidence 

 that the tendency of the rabbits to increase 

 will be kept in check by a corresponding 

 increase in the snakes which prey on them. 



In this country we are blindly tending to- 

 ward similar results, by a somewhat differ- 

 ent method. We do not refer to the pro- 

 posed importation of European hares. There 

 is nothing to apprehend from that measure 

 if carried into effect. If easily acclimatized 

 they would form a valuable addition to our 

 game supply, and the mink may be relied 

 on to maintain a just balance, and prevent 

 any undue increase. 



But we have in North America field mice, 

 shrews, and other small rodents, with a meas- 

 ure of fecundity quite equal to that of rab- 

 bits, and equally ready to become the " bloat- 

 ed monopolists " of this country, if man will 

 only interfere and exterminate the hawks 

 and owls which prey on them. The earth is 

 preserved in a fitting condition for human 

 progress, by the maintenance of the balance 

 of life among the lower creation, and any at- 

 tempt to upset that balance by exterminat- 

 ing birds or the smaller predaceous animals, 

 should be engaged in very cautiously 



In this country we may exterminate wolves 

 and panthers with impunity, because we 

 ourselves are capable of performing their 

 functions, and can keep the creatures they 

 prey on within due bounds, but when it is 

 proposed to exterminate hawks, owls, or 

 insectivorous birds, we should hesitate to 

 act until we are quite sure that we are 

 capable of successfully grappling with the 

 geometrical increase of mice and insects by 

 our own unaided resources. 



