GAME BIRDS AND OTHER BIRDS.

Forest and Bird, Issue 17, 1 April 1929, Page 2

GAME BIRDS AND OTHER BIRDS.

By S. D. Potter.

I do not always agree with the methods and opinions of Acclimatisation Societies, because, speaking generally, this interest in “wild life” commences and ends with the word “game.” Further than that they seldom go. If certain native birds are on the increase, providing they are not those that the Societies are warring against, well and good. If those same birds are on the decrease it is still well and good, providing that whatever is the particular fad of the moment is flourishing. Really there is not much fear of any game bird being exterminated, whether imported or native, while there are proper game laws. Sportsmen themselves see to that, the various species concerned are watched, their numbers estimated, close seasons appointed, and the number to be killed limited. Further, there is invariably a reserve of “new blood” to be liberated, or the necessary money to procure it. Here we touch a sore point. Why should a few people be allowed to introduce alien species to the detriment of our native birds and forests, just because they are willing to pay for the privilege of killing them? Just now these Societies have opened hostilities on the shag, because it takes a few trout. Well, so do the people employed in destroying shags. After all, shags are native birds, and there are fifteen species, and it must be admitted that they are of some use or they would not be here, no matter how ignorant of their habits we may be, or how warped our minds. Nowhere in the world are useless species to be found, it is against all the laws of Nature. Once the use for any particular animal has gone, that animal, too, disappears. However, it is to be presumed that for a long time yet there will be people who are not happy unless they are killing something. So we will return to the point where I mentioned that there is little chance of any “game” being exterminated under proper game laws. As an example, fox-hunt-

ing gives a true idea of what can be attained, and without even protecting the fox by law. Foxes would have disappeared from England years ago, had there been no fox-hunting with long purses behind the various “packs” to recompense farmers and others for damage done by the hunt followers and foxes.

However, in the matter of rats, I am entirely in accordance with Acclimitisation Societies. They undoubtedly are one of the greatest, if not the greatest menace to our bird life—native or imported.

The strength of the rats’ position lies in its remarkable powers of reproduction. A European statistician worked out the theoretical progeny of a single pair of rats after ten years as reaching the astonishing figure of 48,319,698,843,030,344,720 ! Of course, this calculation is really of little use, as it assumes that each rat becomes a parent and allows for no deaths, whereas the mortality is in reality very high, thanks chiefly to certain natural enemies.

Now Acclimitisation Societies state that in certain areas opossum trappers catch large numbers of rats and that in these districts native birds are in consequence on the increase! I should very much like to know who started this story, because to anyone who has the welfare of our birds and forests at heart it sounds very much like an attempt to further the interests of those in the “fur trade.” I wonder how many rats the average trapper does catch during a season? (Those I know must be extremely unfortunate, as they very rarely catch any.) I also wonder how many woodhens are caught. Then the question that comes to my mind is how many rats would each trapped woodhen have accounted for?

It should be fairly clear that we cannot cope with the rat unaided. We must have assistance. We must find its natural enemies.

No doubt some people will say: “It has no natural enemies in New Zealand, because it is not a native, it was brought here,” etc., etc. But stay! Both the black (or British) rat and the brown (Norway or Hanoverian) rat came here from Britain. Britain, it must be admitted, has many natural enemies of the rat, principally owls and hawkes.

For instance, the British Board of Agriculture and Fisheries made first-hand observations, examined the disgorged pellets, and carefully weighed all reliable information obtainable. The Board states the food of the Barn Owl to consist chiefly of mice, voles, bats, rats, large insects and a small percentage of small birds, and concludes by saying: “The statement that the chief food of the Barn Owl consisted of game birds has been dis-

proved. . . . The careful preservation of this valuable bird cannot be too strongly urged upon the whole rural community.” With regard to the Short Eared Owl, the Board already mentioned states that during a great plague of mice in Gloucestershire these owls appeared in great numbers and materially assisted in destroying them. They also proved markedly useful during the last severe plague of voles in the South of Scotland.

The summing up is as follows: “It would be difficult to condemn too severely the foolish and cruel action of those who allow or encourage the destruction of this useful and beautiful bird, and it was with much satisfaction that they were able to record that many land-owners and game-preservers had become convinced in late years that owls of all sorts are not only harmless to game, but most beneficial to agriculturists and had issued orders for their preservation.

The following extract refers to that beautiful little falcon, the Kestrel.

“The wholesale destruction of such birds as the Kestrel is frequently the main cause of abnormal and sudden attacks upon crops by animals and insects. In favourable conditions of climate and other circumstances, and in the absence of the checks provided by Nature against their undue increase, certain animals multiply exceedingly and do infinite harm, as was exemplified by the serious injury occasioned to grassland in parts of Scotland by voles in 1892. Insects also appear more frequently and in large numbers in these later days owing in some measure to the destruction of certain birds, their natural enemies.”

One could go on to greater length, quoting bird after bird that has in the past been sadly and erroneously depleted in numbers because their true value had not been ascertained.

Nearer home, the salvation of Lord Howe Island brought about by owls comes to mind.

I have endeavoured to show that in Britain the rat has many natural enemies. Now, I am not advocating the release of any of these birds in New Zealand. The point I want to impress is that the rat is not a native of Britain any more than it is of this country! Both the rats mentioned are of Asiatic origin and first appeared in the British Isles about the 13th century. Yet some of the British native birds soon commenced to prey upon them! What of our own owl, the Morepork? He has already commenced a crusade against the rat, but what praise, thanks, or encouragement does he receive? What of the Woodhens who patrol our forest floors? (and that opossum ■ trappers destroy). What of the wholesale slaughter of the Harrier? But perhaps that is partly why Acclimatisation Societies find so many rats to cope with and game birds decreasing.