Recent changes in the fauna OF NEW ZEALAND.

Otago Witness, Issue 1159, 14 February 1874, Page 6

Recent changes in the fauna OF NEW ZEALAND.

(By T. H. Potts, F.L.S., in the Field.)

In all observations on the ferce nattcrce of New Zealand, an important fact constantly presents itself, namely, that, in a comparatively short space of time, a marked change has been effected in the fauna through the agency of civilisation. In a great measure this has been brought about by the increasing destruction of many native species, which are now in consequence fast dying out. At the same time, if, through the indifference of an increasing population or a mistaken zeal in enriching museums, many peculiar and interesting forms are becoming extinct, the introduction of foreign birds by private individuals and acclimatisation societies has added several new species to the New Zealand fauna, which it may be hoped are of sufficient value to render their importation a benefit to the country. The introduction of foreign birds is attended not only with expense, but with considerable difficulty, and many attempts have failed simply from the length of the voyage and want of proper care and attention on board ship. Yet, notwithstanding these drawbacks, several successful importations have gradually produced effect, and the imported species have multiplied so rapidly that the character of the avifauna in parts has been considerably affected thereby. In the North Island the common pheasant and Californian quail have increased wonderfully, and are still spreading over a large extent of country ; and it is satisfactory to find that the Maoris, instead of destroying, encourage and protect these new comers. Starlings, sparrows, and finches have in many parts established themselves about the cultivated districts and homesteads ; while in the Province of Nelson especially acclimatisation has been in many cases most successful. There the skylark, which in point of song generally ranks next to the nightingale, is becoming quite common. For miles along the road from Nelson to Christchurch it Hoars and sings as in England. Upon the well-known sheep valks of the Cheviot Hills many imported birds may be noticed, amongst others the partridge, blackbird, and thrush. Although in most other districts nothing of a satisfactory nature can be reported of the reproduction of the blackbird and thrush, notwithstanding the large number turned out, an instance may be cited to show how well other imported species have thriven and increased. In October 1863 a pair of greenfinches were liberated, which had been purchased by auction for five guineas. The sole occupant of their first nest was one callow nestling ; but before the warm days of summer had quite passed away a second family of five were reared, and m the succeeding winter a flock of eight were seen daily. In the following year, late in autumn, more than twenty were flushed from a little patch of chickweed, and since then they have spread so far and wide that the greenfinch's note is now a well-known sound.

The musical whoop of the black swan is sometimes heard as the wedge-shaped flock passes over. This grand addition to our list of birds was introduced to clear the Avon from the pest of water-cress, which in a few years had grown into such thick masses as to impede the stream. No doubt they cleared a wider pathway for the current, and for a while seemed happy and contented ; but gradually they stole away to find more secluded quarters. and were only heard of now and then as appearing on distant lakes and tarns. Less than twenty pairs were liberated by the Christchurch municipality, and yet they are now represented by many hundreds ; as many as five hundred having been counted within a very small area on the Haswell. In Otago, Marlborough, and Nelson they are to be met with in many localities in goodly numbers, for they occupy lakes, rivers, and standing pools quite regardless of provincial boundaries. In the towns of Kaiapoi and Christchurch flocks of pert sparrows are as busy on the roads as in any English village ; the change of climate has not abashed the impudent cock sparrow, nor weakened the hereditary attachment of the species for man's society. Pledges of this friendship are sometimes discovered in wot weather by finding gutters or waterspouts choked up by their warm but untidy nests. The blue gum tree (Eucalyptus) affords plenty of shelter, and is found to be a favourite nestingplace. The pink-pink of the spruce chaffinch is now constantly heard about our gardens ; to these also does the hedge sparrow flit, to hide away her blue-green eggs. How many pleasant memories of home are recalled by the cawing of rooks — the old familiar sounds that woke into drowsy life the vicarage elms and the long avenue that led to the squire's hall. In Otago, where the introduction of small birds has been managed with much forethought and care, acclimatisation has been very successful; in all probability

the southern portion of the Middle Iswill rival the northern part of New Zealand in the number of its game birds. It may be readily seen how our bird system is affected by importations, but we have no clue to the extent of the changes which the next few years may present. The various species which have been mentioned may be now fairly considered as established, and although the list might have been swelled with the names of many other birds which are supposed to be thriving because they have been ttlrned out or have escaped, we cannot speak of them with such certainty. This country dffers such a field for the work of acclimatisation that it has ever appeared to us a subject for regret that efforts of this character are not undertaken on some general plan for the whole country ; we might then perhaps have some guarantee that the species imported are worth turning out, and that when set at large their liberation would be effected in places likely to secure them plenty of fo©d and shelter. If freshlylanded birds, with their wing-feathers cut, weak from a lengthened voyage, be turned out in such miserable plight in the precincts of a town, it requires no conjurer to foretell the result. These birds would have but a sorry chance of living, and cats would fare daintily ; yet this has been done in the name of acclimatisation.

Every rural settler must have observed that our native Anatidse form an important group in the fauna, a fact sufficiently suggestive of the wisdom of adding more birds of the duck tribe. Where nature tells us we must suoceed, should we be neglectful or indifferent ? Nor should it be forgotten that some of the native species are nearly related to birds of the highest culinary excellence. From our intercourse with Australia, America, and Europe, without serious difficulty _ we might obtain waterfowl of the choicest kinds, which would ultimately prove of great value. The success which has everywhere attended our introduction of the pheasant and quail enco\irages the belief that further valuable acquisitions to the fauna might be obtained from the great food-supplying families Phasianidee and Tetraonidse, and nnich of the food of these birds would be dra^n from sources which would not be otherwise economised.

After this brief review of changes in our fauna now taking place from the introduction of foreign birds, the effectsof colonisation on the habits of those species which we know as indigenous should likewise be carefully considered. The widespread cultivation of the soil, the introduction of many foreign fruits and plants, the reproduction of domestic animals by the European colonist, have each in turn influenced the habits of certain of our birds.

Our falcons have been persecuted so persistently that their race has been greatly weakened in numbers. Unfortunately for them, their extraordinary courage has not yet been tempered with discretion ; a bold dash is now and then made amongst poultry and pigeons, but these predatory attacks, intermittent and uncertain, have not influenced their foodacquiring habits in any marked degree. To the more wary harrier, with its greater indifference as to the quality of its food, its grosser appetite, colonisation has added much to its means of living ; from swamps and lagoons frequenter! by ducks and rails, it has been tempted to visit 3heep farms in great numbers. It feeds greedily on carcasses or offal ; it may be observed also lightly soaring over rabbit warrens, and an examination of its castings discloses the help it lends in checking the too rapid increase of a most prolific zodeiit. Owls should be cherished as amongst the number of our best friends ; we have found many specimens of its pellets wholly composed of the fur and bones of mice. The cry of the "more pork" at the barn and rickyard should be hailed by the farmer as the greeting of a welcome guest ; the wanton destruction of an owl is a public robbery, which should be punished with as much severity as sheep-stealing. Halcyons have sensibly increased in numbers as cultivation has spread ; they are true allies of the gardener and farmer, and clear off hosts of insects that invest or devour the produce of agricultural labour. These birds follow closely in the wake of the settler, and may be termed common where they were a few years since considered rare ; last breeding season they were found sixty miles at loast inland. The clear-voiced bell-bird affects orchards and gardens where fruits and flowers abound, and assists in propagating several species of borry-boaring shrubs. The garden likewise has become the shelter and feeding ground of the omnivorous Zosterops, which may be looked upon as the most successful of self-in-vited colonists. The tiny wren (Acanthisitta) reproduces its kind amongst the improvements and amidst the bustle of the woodland homestead ; ita nest has more than once been found in the mortice hole of a stockyard post. Its appetite has be-

come depraved to a certain exteht p"erhaps by its close acquaintance with the Pakeha, as dead bodies of this pretty little species of creeper have been found in hog-tubs— the floating particles of fat had been the tempting but fatal lure. The grey warbler (Gerygone) is now a constant inhabitant of the garden (it has learnt to supplement moss, lichens, spiders' webs, and other nesting materials with threads of cotton or worsted wool, &c), and suspends its cleverly-constiucted home from the hanging sprays of the blue gum (Eucalyptus) or fixes it within the sheltering hedge of gorse (TJlex) ; this habit affects the domestic economy of the Cuckoos, for both Eudynamis and Chrysococcyx make use of this warbler as a dupe. Last siirtimer instances occurred oi both these migrants being reared in gardens in and around the town of Christchurch ; and the whistling cuckod (Ch*ysococcyx) was more abundant there than usual. The tit (Petroica) haunts gardens, and watches the labourer upturning the soil with all the confidence that is displayed by the redbreast at home. The brown creeper (Certhiparus) visits the meat gallows of the stations, for the sake of picking off morsels of fat, and is often associated when so employed with the noisy parokeet. The latter species takes tribute from the cornfield and fruit garden when an adjacent bush affords it a refuge. Flycatchers (Rhipidurse) of two species frequent sheds and houses, in the autumn especially, finding abundance of food in the minute insects that infest man's habitations ; this habit we noticed after the domestication of the house fly, said to be introduced here by the cattle ships from Australia. The raptorial habits developed in the kea (Nestor) in certain Alpine districts is an interesting and peculiar incident in bird history. The omnivorous woodhen, which shows so strong an inclination to avail itself of the advantages of the settler's improvements, is too mischievous to be tolerated ; the farmer's dogs act as police to restrain or deter from pilfering this Arab of the bush. The pukeko or purple gallinule (Porphyrio), and the paradise duck or New Zealand sheldrake (Casarca) are not esteemed as friends by the farmer, who begrudges them the tender grass or growing grain which attracts them to his land. The gulls (Laridfe), which follow^ the labours of the ploughman with beneficent industry, have lately discovered a fresh and abundant food supply. Since the ■establishment of meat-preserving and boiling-down factories in certain spots, these birds may be observed collected together in thousands, feeding on the refuse which has been carted away from these great butcheries. The common tern (S. Antarctica) constantly follows the newly turned furrow, and greatly benefits the agriculturist by its persevering search for larvee and other insect food.

It may be gathered from these remarks how many species of native birds seem to be natural allies of man in checking the undue increase of that which is hurtful to his interests, and which in Buch a climate might bucome a plague but for their interference and assistance.