THE RELATION OF BIRDS TO AGRICULTURE IN NEW ZEALAND.

New Zealand Journal of Agriculture, Volume XXVII, Issue 4, 20 October 1923, Page 227

THE RELATION OF BIRDS TO AGRICULTURE IN NEW ZEALAND.

V. THE KINGFISHER, THE CUCKOOS, AND THE PARROTS.

J. G. MYERS,

B.Sc., F.E.S., R.A.O.U., and ESMOND ATKINSON,

Biological Laboratory, Wellington

Throughout this series of articles it has been the aim of the writers to state facts and nothing but facts. The agriculturist is often forced to realize the damage inflicted on his interests- by birds, and it is only natural that this should be uppermost in his mind when he thinks of birds. It is the more natural since the good services of birds are among the silent processes of nature, which do not become obvious until naturalistic studies are bent upon them. The enthusiastic bird-lover, on the other hand, is not often concerned directly with agricultural interests ; he may be carried away entirely by his strong perception of the good birds do, and, as a result, the cause of the birds themselves is his first object. Shelf ord goes so far as to state that “ When one comes to love an animal or a group of animals he is in no position to draw scientific conclusions regarding it ” ; but to the present writers this seems an extreme view. The aim of these articles is to present the exact scientific standpoint, and to preserve a just balance between the prejudices of the farmer and the enthusiastic eulogium of the bird-lover. That they have been at least partially successful in this endeavour is indicated by accusations now levelled against them with considerable frequency of, on the one hand, making out too good a case for the birds, and, on the other, of making it not good enough. In no case is this balance more necessary than in that of the kingfisher next bird on the list.

THE KINGFISHER (SAUROPATIS SANCTUS VIG. AND HORS.-).

There is probably no need to describe to New Zealand readers either the form of the kingfisher, with its long sharply-pointed beak,

and beautiful blue and green upper parts relieved by a buff or even yellow breast, or its nest in a clay bank or decaying tree-stump, containing pure-white roundish eggs. The numbers of kingfishers vary extremely with the locality and with the season. In the southern portions of the North Island, for example, there are many districts where the kingfisher may be reckoned a rare bird. In the North Auckland Peninsula, however, it is one of the commonest of birds, and it is there, consequently, that it enters into the closest relations with agriculture, and there, moreover, that a request has been recently made to deprive it of all protection, in order that its numbers may be thinned. ,

The kingfisher is extremely plentiful also in the actual vicinity of Auckland, whence the writers have had the good fortune to receive the following authoritative notes by Mr. R. A. Falla, R.A.O.U., than whom there is in New Zealand no more reliable ornithologist : —

Notes on the Food of the New Zealand Kingfisher.

Of the widely distributed family of birds known collectively as kingfishers only one small subfamily is structurally adapted for living exclusively on a diet of fish. These, represented by the common kingfisher of Europe, have a narrow spear-like bill, compressed and grooved to give it cleaving-power, and the very short tail common to most diving-birds. The other extreme is represented by the laughing-jackass type, which has a heavy bill broadened for holding small reptiles, and strengthened for crushing.

The New Zealand kingfisher is structurally nearer to the latter type, and one would expect to find his diet regulated accordingly. This seems to be the case. Although he has just sufficient resemblance to his English relative to enable him to fish rather clumsily when opportunity offers, his regular diet consists of almost every kind of living creature except fish. The following notes refer to the Auckland District, where ' the kingfisher is probably more common than anywhere else in New Zealand, and are based on close observation at all seasons of the year over a period of eight years : —■

Crabs : As probably 90 per cent, of the kingfishers in the district live on the banks of tidal creeks and estuaries, where they appear to feed exclusively on small crabs, these form the most important item as far as this district is concerned. The concrete casing of the drain which runs across Hobson Bay is often dotted for its whole length of over a mile with the pellets of indigestible parts which the bird voids from its crop. One day’s collection of these pellets contained the remains of over a thousand small crabs. '

Crickets : The inland birds are mainly insectivorous. They usually stay the whole year round in one locality, and feed on whatever insect is most abundant at the time (and suitable for food). In the spring of "1917 the kingfishers at one end of the Auckland Domain appeared to be living on crickets, judging from the few pellets found (they are more; difficult to find among trees and vegetation).

Other insects : The birds under observation in the Domain, as noted above, varied their menu at different seasons. During some months they frequently hunted in the vegetable-gardens, but I could not always discover what insects they were taking. Ants often appeared to be the victims. They seem to prefer larger insects when obtainable, and are frequently seen with dragon-flies and cicadas. Soft-bodied larvae were seen being given to the nestlings on several occasions. .

Worms: Kingfishers have a very quick eye for the slightest‘appearance of an earthworm, but do not seem to get many.

Mice . I have seen a bird with a well-filled neck and a mouse-tail hanging out of its bill.

Lizards : My observations here include only half a dozen cases of kingfishers being seen with lizards, although Guthrie - Smith states that at certain times lizards form nearly all their diet.

Small birds : I have seen kingfishers once or twice battering white-eyes’ bodies, which presumably they swallowed later.

Fish : On the only occasion on which I saw a kingfisher actually engaged in fishing the bird made an awkward dive into a pool (flopped in) and fluttered out without anything visible in its beak. It may even have been after freshwater insects or tadpoles.

The habit of throwing up pellets containing all the indigestible portions of the prey —shells, fur, feathers-is shared also by the owls. It obviously offers a striking opportunity to gain an accurate knowledge of the birds’ diet, and renders possible the comprehensive survey which Mr. Falla has supplied. It should be remembered that this account claims to deal with the kingfisher’s habits in one district only. Probably in certain other districts fish form a larger proportion of the diet than in the vicinity of Auckland ; but this is unquestionably not the case in the North Auckland Peninsula as a whole. There the chief food consists of crabs, crickets (Gryllus servillei Sauss.), longhorned grasshoppers (Xiphidium s&mivittatum Walk.), and probably locusts (Locusta migratoria Linn.). The luxuriant summer growth of paspalum harbours immense numbers of crickets and grasshoppers. Crickets constitute a veritable pest, particularly abundant ’ on recent bush-burns, where much of the young grass is destroyed by them and establishment frequently delayed. This large black cricket is believed to have been introduced from Australia. In the North Auckland district it has increased to a phenomenal extent, so that it is no uncommon occurrence to surprise as many as thirty or forty beneath every dry cake of cow-dung turned over in a pasture. Cases are known of large holes being eaten by these voracious insects into coats laid temporarily on the grass. The writers believe that the unusually large numbers of kingfishers in the peninsula are due to the tremendous access of food supplied by the crickets. It is an incontrovertible maxim of economic ornithology that, within wide limits, birds eat the food which is most easily obtained and most abundant. Unquestionably the most plentiful kingfisher-food in the north of New Zealand is formed by the seething grasshopper and cricket population of the northern grasslands.

In Australia, where an almost identical form of our species is known as the “ forest kingfisher ” —a name in itself significant stomachs of those examined by Cleland and his associates contained fresh-water crayfish, weevils and other beetles, and locusts and grasshoppers. In the summing-up it is described as a useful insectivorous bird.

The English kingfisher, which gave its name to the whole family, is, as Mr. Falla points out, structurally fitted to live almost exclusively on fish, yet it is rigorously protected in England. When the early naturalists found in other lands birds of the same family living entirely on land-animals, dwelling in the forest miles from water, they realized the inappropriate nature of the. name “kingfisher,” and suggested instead that of “ kinghunter.” The latter title should rightly be applied to the New Zealand species; but so firmly fixed in the language is the former name that change is almost impossible. In the attempted persecution of this bird as an allegedly ’ serious enemy of trout the writers are unable to see any other justification than that afforded by the proverb “ Give a dog a bad name and hang him.” .

THE LONG-TAILED CUCKOO (URODYNAMIS TAITENSIS SPARR.).

The long-tailed cuckoo, or koheperoa, is one of New Zealand’s three regular migrants, breeding here in summer and spending the winter in the tropical islands of the PacificFiji, Samoa, the Solomons, the Marquesas, and other groups — accomplishing twice yearly a journey of over a thousand ’miles. Its plumage, barred with dark brown, and its excessively long tail, render it quite unmistakable. Fulton has published a very interesting account of this bird, from which much of the following information has been gathered. His paper is so exhaustive that the work of the present writers has been able to add very little to it.

The most interesting feature of this, as of most other cuckoos, is' its well-known habit of delegating its parental duties to other and usually smaller birds by depositing its eggs in their nests. The disproportionately large nestling is assiduously fed and reared to maturity by the devoted foster-parent. Having regard to the interest of this habit, and of its familiarity to all, it is truly remarkable that so little is known as to the foster-parents of the long-tailed cuckoo and as to the method of depositing its eggs in strange nests. Young cuckoos of this species have been found in nests of the yellow-breasted tit, the whitehead, and the yellowhead. The grey warbler, South Island robin, brown creeper, tui, white-eye, bell-bird, and pigeon are —on more or less circumstantial evidence to' act on occasion as fosterparents. Further observations on these points would be of the greatest interest.

The habits of the koheperoa, largely -on account of its noiseless flight and semi-nocturnal activity, are shrouded to a considerable extent in mystery. _ One point, though, is clear — the unsavoury reputation borne by cuckoos the world over as stealers of birds’ eggs and killers of young birds is entirely merited by our long-tailed cuckoo. The detailed researches of Fulton indicate, however, that most of its energies in these directions are bent not on the indigenous and insectivorous bush-birds, but on the introduced small birds which in many localities form a pest of the cultivator. A few quotations will make this clear. “I have seen a cuckoo repeatedly with young birds in its bill, and have examined the nest after the cuckoo has been at them, and have found nothing but the shell of the egg left. It chiefly robs sparrows’ nests ... I have seen one go into a red-pine tree and take from a hole in the trunk a young sparrow, fly into the scrub with it, and in a short time return and repeat the performance with another nestling.” Other birds or their eggs taken by the long-tailed'cuckoo include introduced thrush, linnet, bell-bird, brown creeper, and introduced blackbird. Fulton states further : “ There are very few instances of egg-robbing recorded, and those only since the introduction of English birds, and, as the natural food of the cuckoo has become scarcer, the bird has acquired the habit of. helping itself from the nests of those who have largely been responsible for the diminished food-supply. Many of my correspondents state that the cuckoo is now more common than it used to be, and attribute this to the abundance of imported birds. . . . Imported birds seem to live and breed in the vicinity of cultivated country, consequently near townships their nests and young are much more easily found and are much more numerous than

the native ones, and it seems to me that the cuckoo is living on the eggs and young of these birds ; and, as they are more numerous near dwellings and gardens, the cuckoo also comes closer, and is more in evidence than it was. ... I think that if the matter is gone into it will be found that the cuckoo does the best he can towards combating the sparrow plague.”

The long-tailed cuckoo, then, must be considered an enemy of the introduced small birds, against which have, been introduced barn-owls and more recently the little owl. The whole question of these introduced small birds will be dealt with fully in the later articles of this series. At the present time it must suffice to state that even if certain species of them are doing more good than harm, many of them are such that an all-round reduction of their ' numbers would' render , them less liable to attack crops, and would thereby increase the percentage of good services rendered by them. Such are probably the house-sparrow, the yellowhammer, the skylark, the starling, the mina, and the rook.

THE SHINING CUCKOO (UAMPROCOCCYX LUCIDUS GM.).

It is probable that many people know the characteristic whistle of the pipiwharauroa and are yet entirely unfamiliar with the appearance •of the vocalist. This little bird, with its distinctly barred breast and beautiful bronze-green back, is another of our few migrating birds. In its case, however, according to the recent researches of Mathews and Iredale, the winter home is quite unknown. Formerly it was believed to winter in northern Australia, ‘ but now (although proof is lacking) it appears that New Guinea is more probable.

The most frequent foster-pax ent of -the shining cuckoo, or “ whistler,” is the grey warbler ; but cases in which the white-eye, the yellowbreasted tit, and even. the house-sparrow acted in this capacity have been recorded. In the case of the grey warbler, with its covered-in nest (see Journal for August last, p. 80), it would seem almost impossible that the cuckoo can enter and actually lay her eggs in the nest-cavity. It seems almost certain that she must lay her egg upon the ground and deposit it in the nest with hex’ bill. In this connection Mr. P. Keegan, of Whakatane, writes, under date 27th September, 1922 : ‘ When a lad on Banks Peninsula I often watched the shining •cuckoo placing an egg in the grey warbler’s nest. A cuckoo would approach the nest, and the two warblers would make a fierce attack on it. The cuckoo would lure .them away some distance. Then its mate would dash in with an egg in its beak and place it in the nest.” Other foster-parents mentioned by Fulton are fantails, robins, tomtits, blackbirds, and sparrows.

The shining cuckoo shares with the well-known English cuckoo and •other typical members of the family the ability to eat hairy caterpillars, which are' usually believed to be distasteful to other birds. It is true that McAtee considers that hairy caterpillars in general are by no means so objectionable to birds as is usually supposed, and he instances the English house-sparrow destroying large members of the white-marked tussock-moth caterpillars {Hemer ocamja leuco stigma S. .and A.) ; but there cannot be the slightest doubt that cuckoos are better adapted than other birds to this diet, and in actual fact they do make a specialty of hairy larvae. The same author describes the yellow-

billed cuckoo (Coccyzus americanus) and its method of treating the hairy tent-caterpillars (Clisiocampa americana). It squeezed out the juices and dropped the hairy skin to the ground. Mr. W. W. Smith, in this country, has watched our shining cuckoos feeding on the dark extremely hairy caterpillars of the common black-and-white moth (Deilemera annulata Boisd.). It proceeded in exactly the same way as its American cousin, pressing the larvae between its mandibles and rejecting the empty skins. Among other more or less hairy caterpillars eaten by the shining cuckoo may be mentioned-those of the “ kowhaimoth,” which Mr. G. V. Hudson considers is almost certainly Mecyna maorialis Felder. - ■'

So far as New Zealand conditions are concerned, it seems dear that the shining cuckoo is practically purely insectivorous, and might therefore have been granted notice in our preceding article. Fulton, however, believes that at times it feeds on the eggs of small birds least one of his correspondents having seen it in the act. The same writer mentions moths, daddy-long-legs (Tipulidae), caterpillars, flies, gnats, and “ fruit-slugs ” as appearing in the cuckoo’s menu. He even quotes a correspondent who accused the shining cuckoo of eating Burbank plums ; • but this is, on the face of it, so' utterly at variance with the general food habits of the cuckoo family that it needs confirmation before it can be accepted as true. With regard to the highly injurious fruit-slug, the larva of the pear and cherry sawfly (Eriocampoides limacina), the writers know of several cases in which the shining cuckoo has eaten very large numbers, and there can be no doubt that in this direction it performs a good service for the orchardist.. Cleland and his associates found a closely related Australian cuckoo with no fewer than twenty-five cutworm’ larvae in its stomach. They further state, “ All cuckoos are evidently highly useful insectivorous birds, feeding especially on various caterpillars.”

THE PARROTS.

The parrots of New Zealand include, the kaka, the kea, four species of parrakeets, and the now extremely rare kakapo. Of these the kea will form the subject of an entire article at a later date ; while the others are among the most exclusively, forest-dwelling species of the indigenous birds, and as such have been.briefly discussed in the second part of this series. The kaka, the parrakeets, and particularly the kakapo have all decreased to a. very great extent under the adverse influence of bush-clearing and settlement, which deprived them of the forest habitat to which they were pre-eminently adapted, and they found it impossible to subsist in settled districts. It is true that the early colonists of the South Island saw vast irruptions both of kakas and of parrakeets, which descended in countless hordes on the cultivated areas, committed extensive depredations on various crops, and proved for a limited period a pest of the greatest magnitude ; but, in spite of our ignorance of the abnormal conditions which produced these vast immigrations, it can safely be asserted that such are never likely to occur again.

The kakapo (Strigops habroptilus Gray) is now so rare that it need not long detain us here. As one of those especially interesting and anomalous flightless birds of which New Zealand possessed such a

unique assemblage it was one of the first to suffer from the attacks of the various predaceous animals and vermin introduced by Europeans, Its diet is almost entirely vegetarian, consisting largely of grass, moss, and similar vegetation, which it grazes almost like a mammal and of which it devours large quantities.

The Kaka (Nestor meridionalis Gm.).

The kaka, with its almost wholly olive-brown plumage, the bright red of the under-surface of the wings when seen in flight, and the grey crown which inspired the founder of the genus to which it belongs to dedicate it to the. venerable Grecian orator, is one of the most easily recognized birds of the forest. This is the more so since its clamorous notes are not easily mistaken. The white eggs are laid on the more or less bare floor of a hole in a tree, often at or below ground-level in an entirely hollow trunk, the entrance being a comparatively small hole high up the tree.

The feeding-habits of the kaka may be conveniently discussed under the three heads of berry-eating, honey-eating, and ' insect-eating.

With regard to the first, the efficiency of the kaka as a seed-disperser must be impaired by its habit of breaking up with its powerful mandibles the larger seeds on which it feeds, and in this direction it would perform much less service than that prince of seed-distributors the pigeon. It must be emphasized, however, that this point should be investigated, as at present practically no data are available regarding the treatment of the different forest-fruit kernels by the kaka and by the parrakeets. It is a matter in which the closest field observations are necessary.

The tongue of the kaka is modified in a very remarkable manner as an organ for extracting the nectar from flowers. . Of the latter the rata (Metrosideros spp.) is a favourite. The dispersal of the rata-seeds is not easily explained ; they appear too heavy to be blown far by the wind, while juicy flesh which would be attractive to birds is lacking. Guppy has therefore suggested that the seeds may become to some extent entangled in the feathers, of the kaka when, these heavy and active birds are busy in clamorous activity among the later blossoms of the rata.

As an insect-hunter the kaka has few rivals. Buller graphically described these birds “ climbing up the rough vine-clad boles of the trees, freely using their powerful mandibles, and assuming every variety of attitude, or diligently tearing open the dead roots of the close epiphytic vegetation in their eager search for insects and their larvae.”

In summing up the activities of the kaka we cannot do better than use the words of the same ornithologist (Buller) : “ It is strictly arboreal in its habits, and subsists to a large extent on insects and their larvae, so that it is probably one of our most useful species. Where they exist in large numbers they must act very beneficially on the timber forests ; for in the dominion of nature important results are often produced by apparently trivial agencies. Like all the honeyeaters, while supplying their own wants they do good service with their brush tongues by fertilizing the blossoms of various trees, and thus assisting in their propagation; while, on the other hand, the diligent

search they prosecute for insects and grubs, and the countless numbers daily consumed by each individual, must materially affect the economy of the native woods.”

The Parr afreets.

Of the four species of these beautiful birds found in the New Zealand region, one is confined to Antipodes Island, while a second, the orangefronted parrakeet, is apparently practically extinct.- The remaining twothe red-fronted (Cyanoramphus novaezealandiae Sparr.) and the yellow-fronted (C. auric efts Kuhl) — are widely distributed over both islands of the mainland where suitable areas of bush are to be found. Both birds are almost wholly green in colour, with a red forehead, but the crown of the head of the red-fronted is crimson, while that of its rather smaller relative is yellow. Both lay their roundish white eggs in the holes of trees.

Of their feeding-habits little of a detailed nature is known. They appear to be rather more vegetarian in their tastes than the kaka, and to subsist very largely on berries. The black juicy fruit of the tutu (Coriaria sarmentosa} is much relished. - It is said that the Antipodes Island species feeds largely on the seeds of the piripiri, hutiwai, or “ biddy-bid ” (Acaena sp.). Reference has already been made to the vast flocks of parrakeets which visited settled areas in the early days, and from the ravages of which scarcely any kind of seeds, grain, or fruit escaped. Under such conditions the parrakeets were as great a pest as the hordes of cockatoos still are in portions of Australia but under present conditions their numbers are so much reduced, and they are confined so entirely to the forest, that their economic importance can be considered only from the forestry viewpoint. In their present numbers they must therefore be included among the predominantly beneficial birds.

REFERENCES.

Buller, W. (1882) : Manual of the Birds of New Zealand. Wellington.Cleland, Maiden, Froggatt, Ferguson, ■ and Musson (1918): The Food of Australian Birds. ACS. IF. Dept.'of Ag. Sci. Bull. 15. Fulton, R. (1904) : The Koheperoa, or Koekoea, Long-tailed Cuckoo {Urodynamis taitensis). Trans. N.Z. Inst., vol. 36, pp. 113-148. (1910) : The Pipiwharauroa, or Bronze Cuckoo (Chalcococcyx lucidus). Trans. N.Z. Inst., vol. 42,

pp. 392-408.

Hutton and Drummond (1905) : Animals of New Zealand.

McAtee, W. L. (1922) : Local Suppression of Agricultural Pests, by Birds Smithson Rept. for 1920, pp. 411-438.

Mathews and Iredale (1913) : A Reference List of the Birds of New Zealand. Ibis, ser. 10, vol. 1, pp. 201-263, 402-452. Shelford, V. E. (1913) : Animal Communities in Temperate America. Chicago. Smith, W. W. (1923) : Feeding-habits of the Shining Cuckoo. N.Z. Jour. Sci. & Tech., vol. 6, p. 61.

New Rabbit District. The constituting of the Kiwitea Rabbit District (Wellington) for the purposes of Part III of the Rabbit Nuisance Act was gazetted on 13th September.