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Bird Life on Island and Shore

XI. Kotiwhenu

page 104

XI. Kotiwhenu.

The weather continuing fine, we were advised to proceed on our way whilst such conditions lasted. We again therefore sailed south. No very definite destination was in our minds as the Dolly passed out of Pegasus harbour into the ocean. Neither of the Leasks nor myself had any knowledge of bird life in the islets we intended to explore; nor had it been possible to obtain from others information of any certain sort. I am bound to say, however, that our appetite for research was whetted by descriptions given. Evidently there was no lack of curious birds. Our crew, and indeed almost all of the local fisherfolk whom we questioned, knew of species about their coasts which, if correctly described, had certainly not yet been classified. I may say at once that we never came across these remarkable birds, though we thought afterwards that several of them might quite well have been the Goldfinch, the Starling, and the Yellow Hammer; the sun striking on the page 105 plumage of any of these might indeed have excusably suggested adjectives not altogether extravagant applied to Birds of Paradise. Even a Sparrow multiplied in bulk, his browns made super-browns, becomes on the tongues of men unaccustomed to the descriptive art, and in the ears of men hoping still for undiscovered species, a bird of respectable plumage and exceptional aspect.

Thus ignorant of what we might or might not encounter, and with only unreliable descriptions to lead or mislead us, we determined to search island after island until one suitable to our requirements should be found. As the Dolly could only plant and transplant us whilst the weather remained calm, above all things it was important that we should not be stranded where rats were in possession. Time would have been wholly wasted, for where vermin have obtained a footing, as on Entrance and dozens of other islands, rarer species have been annihilated, and even sea-fowl decimated.

With mingled hopes and fears, therefore, but at any rate with the certainty that we should see much that would be new, we passed into the open sea. This belief was at once justified, for immediately we found ourselves amongst larger numbers of birds than almost I had deemed possible. We sailed alongside, and sometimes nearly page 106 through, scores of revolving rings of Grey Petrel—Mutton bird,—some of the circles consisting of hundreds and some of thousands, but each apparently self-contained and not mingling with other groups. About the centre of each ring thronged birds in every attitude of motion and repose, some momentarily quiescent, gorged, others feeding in furious haste, till in their turn ousted by newcomers fiercely impatient for their share in the feast. There were birds on the water, birds about to alight on it, birds rising from it, all pursuing the same circular course, until each moving mass became a waterspout of birds, narrow at the base, wider above, its particles rapidly gyrating in the one direction. The hollow circle shape, or rather vase shape, for it narrowed at bottom, was due presumably to the constricted area on which the food was floating and to the wheeling drop to water of bird after bird in unending succession. There was no room for divergence of flight; each individual had perforce to follow his neighbour in a circular fall to ocean, and again to follow his neighbour in a circular upward rise. Birds ousted from the water by the crush seemed, after a moment's sidewise pause, to gather sufficient impetus to begin the round once more. From the food-supply centre they spun in wide and wider circles, far flung as if by some centrifugal force, each individual gyrating with desperate velocity; page break
Mutton Bird[Twilight and Dawn].

Mutton Bird[Twilight and Dawn].

Dawson's Petrel (M.).

Dawson's Petrel (M.).

page break page 107 where thickest clustered on the base of the spinning vase, flight was comparatively slow; as distance increased, so proportionately did celerity of circumrotation. Except that man is a clumsy slow-footed creature, and except that football is played on the flat, if a tight scrum as enacted at Rugby in the 'eventies can be imagined revolving, with forwards bursting through in order to regain as rapidly as possible their proper positions, all likewise wheeling in one direction, some faint conception may be gained of the eagerness of each Petrel to regain the centre of events. Remarkable, however, as was the funnel-shaped mass of birds in outline, its aerial balance was no less amazing; wings were used only to break the fall waterwards and to rise. Once off the water, the birds, catching the wind, circled wide and wider, fast and faster, without beat of wings, without stroke of pinion. It was an exhibition of exuberant vitality consequent on stimulating food, probably in this case on extremely stimulating food, for birds are affected almost instantly by what they swallow. These Petrels were drunk with energy, mad with wild zest of life. For hours we passed through masses of feeding birds, each individual of each feeding flock seeming to adhere strictly to his own tribe or clan.

In due course we reached Kotiwhenu. There, after brief preliminary inspection, I decided to page 108 remain—at any rate for a week. As a matter of fact, we never got farther. We could in truth hardly have done better. Species were breeding on it hitherto unknown to me. There were no rats, black or grey.

The Dolly anchored in deep water only a dozen boat lengths away from the cliff, and for further security moored to a convenient rock, the landing of our impedimenta was quickly finished. In less than a quarter of an hour cameras, bedding, and stores had been rowed ashore, and deposited above high-water mark. The anchor of the little craft was hauled, farewells shouted, and we were marooned on our island.

Kotiwhenu fostered an avifauna and flora not affected by the changes that have elsewhere transformed New Zealand into a second England. Its surface conditions remained as they had been centuries before, as they had been anterior to the last great migration of the Maori race. Elsewhere many kinds of native birds have disappeared; everywhere their numbers have decreased; elsewhere in New Zealand enormous changes have taken place in its flora. On our island, conditions were as they had been; there was no reason to suppose that birds were less plentiful, or that there had been any alteration in the relation of species towards one another. Certainly a few aliens, birds and plants, had put in an appearance; page 109 their significance, however, as colonists was negligible. In no wise did they affect the original owners of the soil. As was to be expected, it was in the vicinity of the trodden ground in front of the huts that most of the alien birds were first noticed, and most often noticed. About this minute clearing harboured also such stranger plants as could withstand the climate, but thankful am I to say that none of these foreigners, animal or plant, have any chance of increase. Conditions were adverse, and likely to remain adverse. In other parts the Sparrow has increased. Here on our island the five or six pair seen on three or four occasions—always observed, moreover, on the little space of cleared ground in front of the huts as if clinging to the very shadow of humanity—were never suffered to remain at peace. Of us even they were exceedingly shy, upon our approach at once flying into scrub, where they were chased and harried by Bellbird and Tui. Nor did at night peace bless their rest, for then began the customary hailstorm of Petrel. The wretched Sparrows must have been jarred from their roosts by the fluttering of sea-fowl or struck down by their falls. They never attempted nidification, we felt sure of that. It was impossible on so small an area, searched daily by three experts, that nests so brazen in their effrontery could have been overlooked. For once, at any rate, Sparrows had page 110 come to the wrong place. Starlings were in no better plight; like the Sparrows, they seemed quite unable to obtain permanent foothold. There was no suitable timber. Holes elsewhere that might have suited a Starling would also have admitted the little Kuaka, in which case Starling, nest, and eggs would have been summarily evicted. In any case, these holes would have been too damp for the rearing of young Starlings. At night, too, these aliens, wherever they may have elected to roost, must have been kept in perpetual perturbation. A single Greenfinch was noticed; Redpoles were seen thrice, each time in a different part of our domain. A brace of Goldfinch were also observed. There was not a Song Thrush on the isle. The only British species attempting to breed was the Blackbird. A nest containing eggs was found during our first day. It was afterwards deserted, having from its lopsided appearance been displaced by a falling Petrel.1

On the few yards of open ground near the hut, cleared partly for light and sunshine and partly to facilitate the preparation of Mutton birds for market, nearly two dozen small stranger plants page break
Mutton Birders' Huts, Kotiwhenu.

Mutton Birders' Huts, Kotiwhenu.

page break page 111 had managed to make a settlement. With one exception, these weeds had reached the island as stowaways; the potato excepted, none had been purposely imported. Some of the adventurers had been hidden in sacking or plastered in the soil glued into the eyes of potatoes, or on men's boots or clothes, or in the planking imported for the little huts, or ridden loose in the dust of old ragged bags. Aliens growing on Kotiwhenu at the date of our visit were—some of them are represented by a single plant—cock's-foot, Yorkshire fog, poa pratensis, sweet vernal, rye-grass, tall fescue, white clover, plantain, vicia sativa, capeweed, sorrel, dock, mouse-ear-chickweed, pimpernel, sowthistle—very rank and luxurious—wall speedwell, polygonum aviculare, shepherd's-purse, and pearlwort: these plants had got thus far at any rate on their march to the South Pole. The potato had managed to propagate itself from peelings and tubers thrown aside. We found it growing vigorously on the rich, oil-saturated, highly manured peat in the immediate neighbourhood of the huts, tubering freely almost on the surface.

Kotiwhenu is wholly surrounded by cliffs. In shape it is roughly hog-back, the highest point reaching perhaps a couple of hundred feet. Almost everywhere the surface is covered by peat. Nearly half the total area is bare of undergrowth of any kind, and exposes a surface of bird-worn brown, page 112 as of a gigantic wet rabbit warren. Especially were the lower slopes so perforated by burrowing Petrels that it was impossible to tread without breaking through the surface. Thereabouts, growing out of the bare peat, flourished low, thick-set, gnarled, hard-twigged, rigid tupari woods, their gaunt grey stems naked to the neck, their leathery foliage borne on the topmost twigs, able alike to endure the buffeting of winter blizzards, the drift of salt sea spray, the bird tunnelling about their roots. They were of different ages; there were strips and patches in the last stage of senility, starved of sap, bearing depauperated leaves with no signs of young suckers or shoots or other token of rejuvenescence; there were spinneys of well-grown specimens in their prime; elsewhere again were to be seen healthy saplings. The plant at any rate renews itself from time to time in small irregular areas. Above the steep slopes, on the crown of the islet, grow ironwoods several feet in diameter, sprawling along the ground ere they send up leaders, creeping ere they can stand upright, as is the habit of this southern species. Amongst and beneath them flourished trees of lesser size. Here and there on the island were scattered groups of shabby-looking, loose-rooted tree-ferns, over-manured and undermined, unhappy at the perpetual disturbance of their sparse roots. There were thickets of island grass, page 113 where scrub had been cut for firewood, but even here tupari seedlings and young trees of other sorts in lesser numbers and luxuriance were thickly reappearing. There was not a cabbage tree on the island. The giant nettle was rare. I do not recollect the black vine, often so abundant on the fertile peats of these islands of the south.

The deeper the blanketing of peat, the more suitable does an island become for Petrel. Because Kotiwhenu was a peat island, large portions of the surface were worn bare by bird traffic—seedling trees, grasses, and ferns trampled down and worn away.

As on all “birding” islands, paths—of a sort—were numerous and fairly well defined. A main track more or less free of fallen trees circled the island. Other routes of a foot or two wide opened up the points and peninsulas. Perpetual stooping and crawling, so tiresome on the mainland, was unnecessary. Conditions were indeed almost ideal: insect pests were absent, there were no sand-flies by day, there were no mosquitoes by night. Blow-flies were unknown, we had no anxiety as to provisions, we had no trouble as to blankets hung out to air or left on the bunks.

The weather was extraordinarily changeful. Sometimes in a single day we experienced every vicissitude marked on the meteorological chart— page 114 blue sky, dull, cloudy, overcast, foggy. The sky was even for periods cloudless. The rainfall was small; on comparison it proved to have been considerably less than that of Port Pegasus, where I had left a rain-gauge. That there may be a dry belt south and east of Stewart Island is borne out also by the reports of friends camped from time to time on the Snares, on several occasions the weather there having proved relatively dry, whilst heavy rains had fallen on the mainland of Stewart Island. None of the islands immediately south of Stewart Island rise to any height above sea-level; they are consequently unswept by clouds that retain their moisture till reaching higher lands. After previous experience of weather south of Foveaux Strait, water was an article about which I had not troubled, yet had it not been for half a dozen tins supplied by a chance fishing-boat we should have been seriously inconvenienced; instead of the anticipated brimful barrel, we had water enough only for our simple cookery, barely enough to rinse properly the photographic plates, and almost none at all for washing ourselves. There was but one abbreviated peat burn, oozing from slopes honeycombed by Petrel burrows and running a shallow course of forty or fifty yards over rocks washed bare by winter seas. Its dark stagnant pools, reminiscent of midden overflowings, page 115 were now in addition during summer blocked with the carcases of Petrels in every stage of decay—a gruesome stream indeed. There were two water-holes near our whare, both unfit for use in summer during the height of the breeding season. Their stagnant water was so full of matter in suspension that my plates, even after rinsing in such rain-water as was available, had, on arrival at Tutira, to be rewashed. This want of sufficient water was, however, but a minor ill; it was a delightful variation from the unending blizzards of hail and sleet experienced in the centre of Stewart Island, where in other years we had lived for months in our waterproofs.

There lay diffused over this blessed island, too, a balm of deeper healing to the spirit than glow of warmth and sunny skies. We dreamed no awful auguries of ill; we wakened in the mornings with easy minds and happy hopes; our island was guiltless of rats; there was no risk that the labour of weeks might be undone by these thrice-accursed brutes; there was no risk to the security of nests under observation. We were beyond the daily perturbations caused by newspapers, by the perusal—we devour them with our morning meal, and I have thought what a healthy wholesome tonic they must be for the day—of famine, accident, disgrace, and greed, paid for as pleasant things, gathered as orchids are gathered for our page 116 gardens and conservatories from every quarter of the globe. Lastly—and without it the expedition would have lost half its savour,—I had the tireless aid of two first-class mates. The Leask brothers, John and Albert, were born bushmen and naturalists, and their genuine pleasure in the work added much to my own.

Kotiwhenu, for its size, was more thickly stocked with land birds than any spot of ground I have visited. The exact tally of nests was speedily lost. We must, however, have known of a score of Bellbirds, of a dozen Tuis, of fifteen or eighteen Robins, hatching eggs or feeding young. Of Morepork nests—searched for by me elsewhere for years and still unfound—we got two on the island; whilst, on the principle that it never rains but it pours, I got a third immediately after our return to Pegasus. We had also four Saddlebacks, three Bush Wrens, and two Sea Hawk under observation.

Yellow-fronted Parakeets, a breed I had already photographed in Stewart Island, were fairly plentiful. On Ulva during the month of March I had watched them at close quarters. Now on Kotiwhenu as early as December I found them in occupation of their selected tree holes. Courtship was in progress, and more than once the crowning act of courtship noted. Apparently, therefore, holes are selected some time previous page 117 to extrusion of eggs; maybe the more experienced pairs take possession of good sites, and thus ensure certain accommodation for use at a later period. During the hours of light, and especially about noon, Parakeets sit cuddled together in the green shade of tree-tops; their holes throughout the day are unvisited and untenanted. As darkness approaches the pair fly nestwards; with her mate's sanction—his approbation and encouragement indeed,—the hen leaves him and enters the hole. There then take place further lengthy confabulations, lovers' last, long, lingering good-byes, she with her head only peering out of the crevice, recollecting everything at the last moment, like ladies risen to retire for the night—like ladies cramming their real news into a postscript—he, on a near-by branch, gallant, subservient, courteous to the last, but longing to have it over and get to his quiet cigar and tot or their ornithological equivalents. At last she retires, and he flies off to some safe perch in the woods, leaving her alone in her hollow tree trunk. Four nesting holes of Parakeets were found, and twice we witnessed the strange nightly partings of the little couples.

Though failing to secure the nest, we found the new-hatched brood of a pair of Banded Rails, one of the two pairs on the island. On the other hand, birds, elsewhere plentiful, were scarce. There page 118 were but three pairs of Fantails, one pair of Grey Warblers, one pair of Yellow-breasted Tit, one or perhaps two pairs of Weka. Once a small party of Brown Creepers were noticed—stragglers from the mainland, we believed, as they were not again seen. A single Kaka, perhaps hurt and afraid on account of the Sea Hawk to venture across the intervening sea, lived alone on the tall ironwoods. Once high in the sky I saw a Harrier chased by a Sea Hawk. A few Kittywake and a few Black-backed Gull exist on sufferance. When noticed, they are swooped upon by the fierce Sea Hawk, and hunted off the premises. There was no shaggery on the island, but during calm weather a few Pied Shag roosted in the limited shelter of our landing-place. The only glimpse of any other kind of Shag was afforded by solitary representatives of a breed unknown to us. One of these strangers, passing up the gut of water dividing Kotiwhenu from another islet, was greeted, we thought, by an unamiable chorus from the Pied birds. They resented the presence of a stranger even on the confines of their territory. The Blue Penguin or Rockhopper bred with us. Their eggs, placed on unattainable cave ledges, we could see though not touch. We could mark, too, from the cliffs above, through the clear sea water, the subaqueous approach of the old birds. The Yellow-eye breed was not seen, but once page 119 whilst I was fishing from the rocks three Tufted Penguin landed within a few feet, and, literally blushing past me in the most delightfully friendly fashion, scrambled up the rocks, and walked with an air of possession into one of the turf-thatched igloos. There they stood looking at me with complete unconcern, drying and preening themselves, pleased to be out of the heavy sea that was running. From the assured manner of their progression over the slippery ledges this male and his two accompanying hens were well aware of the haven awaiting them. Lastly, three species of Petrel—the Kuaka, the Mutton bird, and, I believe, Cook's Petrel—were breeding in thousands. Besides, however, the pleasure of thus meeting old friends in new surroundings, there lived also on the island birds unknown to me till then—the Saddleback and Bush Wren; nor must I omit mention of the Sea Hawk, which, though known previously, had been hardly more than noted.

The island was interesting on another account. It was possible, I thought, to observe in the ways of life of several of its inhabitants incipient departure from type, changes small indeed in themselves, but which in time might be capable of producing new forms; perhaps, continued on the same lines through periods long enough, forms sufficiently differentiated to deserve the appellation page 120 of species. Owing to local conditions there seemed to be occurring certain modifications of normal habits—habits that hardly strike us as requiring explanations when we are born to them, accepted with as little concern as are the daily miracles of light and growth.

One of the modifying environments was the nightly shower of sea-fowl, a fall which continues during the whole breeding season of the resident land birds. Thus on the mainland, where no fall of Petrel occurs, the Tui, the Bellbird, and the Robin, I believe, habitually build nests open to the sky. On Kotiwhenu the Tui's nest is placed where protection is afforded by stout, small, covering boughs, branched clusters of twigs sufficiently stiff to fend off a falling bird. More pronounced is the effect of the Petrel fall on the nesting habits of the Bellbird. Of the two dozen Bellbirds' nests known to us on Kotiwhenu, half were built in cavities and tree holes; the others, as in the case of the Tui, placed where other protection was obtainable. Thus in some degree the idea of shelter for their nests in tree holes and chinks is permeating this breed. The Bellbird is a migrant. Undoubtedly there is free and constant communication with the mainland; equally certain is it that a large proportion of Bellbirds of this region breed, not on the barren mainland, but on the islands fertilised by centuries of guano page 121 —islands which are dunghills, and which produce insect food as from a teeming midden. Thus amongst the Bellbirds of these southern latitudes an alternative form of nest structure is gradually coming into existence. When all Bell-birds breed in holes we shall then term the habit instinctive, and so it will be if instinct is sublimated common-sense. Of the nesting habit of the southern Robin on the mainland I know but little, but all Robin's nests discovered on Kotiwhenu were built in shelter of one sort or another, beneath cornices of ancient dead masses of fern frond, beneath projecting timber, spots in fact where of necessity nests had to be built to ensure the preservation of the race.

Differences between North Island species, such as the Pied Tit, the Pied Fantail, the Blue-wattled Crow, and South Island species, such as the Yellow-breasted Tit, the Black Fantail, and the Orange-Wattled Crow, are insignificant. It is impossible now to discover how these minute variations have come about—why, for instance, the Tit of the North should be white-breasted, whilst the Tit of the South should be pale yellow or pale carmine? Probably some small climatic modification has given rise to other modifications, one of which has at last affected the coloration of the plumage, and thus made visible to the eye a change previously existent indeed, but hitherto page 122 passed over because internal. There is in fact a constant tendency amongst septs of a species, under varying circumstances of food and climate, towards small dissimilarities in colour, size, song, and, I believe, too, in shyness of disposition. We have but to suppose the discovery of New Zealand postponed by a few thousand centuries, to imagine the arrival of ornithologists who note the fact that Bellbirds breed in holes; the transformation effected, the link gone, the process of change complete, the fact alone would remain. Should such an alteration yet take place, a hint at any rate will now have been registered as to the why and wherefore.

Another of these departures from typical habits—departures sure sooner or later to induce structural variation—seems to be displayed in the Bush Wren. Watching its way of life, many interesting speculations passed through my mind as to the result of the crowding of species on to yet unsubmerged portions of a sunken land mass. In the movements of this tiny bird, once more it seemed that I might be watching steps—adumbrations, at any rate—towards the creation of a new species. In the case of the Bush Wren it is indeed almost possible to show the positive, comparative, and superlative of change. We must first picture the bird as described in times prior to the rat and weasel plague. It was then common page 123 in the forests of the mainland, a climber of timber, almost like the Rifleman. We must next note the breed on some islet more thickly wooded, less heavily coated in peat, and therefore less densely stocked with Petrel than Kotiwhenu. Lastly, we must view it on Kotiwhenu, positively a ground bird. The factors of change are inability to escape from a limited area, and the increasing persecution of another bird. The Robin is the chief instrument by which nature seems to be shaping out a new species of Xenicus.

Before the arrival of the European, Robin and Bush Wren were alike plentiful in the forests of the mainland. Ample room was there, and verge enough for both in the woods that then covered the country. Food was plentiful, nesting sites abundant. It was impossible that the two species could clash, or that the one could affect the other.

We have now to consider conditions obtaining on the considerable island Te Puka, where Wrens are abundant. Though also a breeding-ground for Petrel, it is covered almost everywhere with ferns and sedge and ample undergrowth; only on certain slopes has the vegetation been eroded with bird traffic. Both Robins and Bush Wrens abound, but owing to the greater area of the land surface and the quantity of cover, the two species are not perpetually in each other's presence. The Wren is less furtive and shy. Though page 124 never daring to venture far into the open, it has on Te Puka not yet altogether lost its character of a creeper. We noted Wrens many times six, eight, and ten feet up the scaly boles of several kinds of trees.

Among the Wrens of Kotiwhenu a divarication still more marked is apparent. Its huge proportion of bare peat, its surface vegetation stunted and worn by bird traffic, its comparative poverty of large trees and healthy under-scrub have already been described. Here the Wren hardly dares venture away from the low shelter of island grass and fern; it never dares to linger. It is ceaselessly pursued by the Robin. During the course of our visit no Bush Wren on Kotiwhenu was seen to attempt the scaling of a bole, even of a bole protruding from the midst of fern—no Wren ever mounted higher than the height of a fern frond.

To recapitulate: in the forests of the mainland, unmolested and with ample space, the Bush Wren—I have come across him on a few occasions—remains a sealer of trees. Circumscribed somewhat in acreage and in considerable degree molested by the Robin, the Wren has on Te Puka become less of a climber and more of a ground bird. On Kotiwhenu, owing to its small acreage and lesser amount of covert consequent on the greater Petrel population, the persecution of the Wren page 125 by the Robin is incessant. It has ceased in any degree to be a tree-climber; all its food is obtained amongst fern and sedge; the species has become purely a ground bird. The food of the Wren in the forest of the mainland, where it searches the boles and crevices of trees, must differ from the food gathered on Te Puka, and in yet greater degree from supplies found in the thickets of Kotiwhenu. The wings of the Wren are fully used on the mainland, partially used on Te Puka, almost useless on Kotiwhenu. With modified habits of exercise and modified food supply, structural changes and changes in plumage may reasonably be anticipated. Given time, the island Wren of Kotiwhenu becomes a form; given unlimited time, it becomes a species.

Another difference betwixt birds known to me in other parts and those permanently resident on Kotiwhenu—autochthones—was in the size of the clutches. Non-migratory species such as the Bush Wren and the Saddleback lay two eggs only. The Robin, too, lays but a brace of eggs, though elsewhere the number is from four to five. The island therefore may be considered stocked to the limit of food supply of these three species. Migratory breeds, on the other hand, such as the Bellbird and Tui, birds that can come and go as they wish, lay the usual number of eggs.

It may be that my premises are too circumscribed, page 126 too frail to bear so tall a superstructure. Speculations, nevertheless, on dissimilarity between species on island and mainland, and on steps and processes likely to terminate in fixity of new habit, are always of special interest. At any rate, the altered size of the Robin's clutch and the altered habits of the Bush Wren, consequent on proximity to the Robin, may supply hints to naturalists of wider comparative knowledge. Some ray of light may have been thrown on the genesis of the two-egg clutch and on the interaction of species crowded together through shrinkage of area and shrinkage of food supply.

1 On an island in Paterson Inlet we had on another occasion got the nest of the Hedge Sparrow, and on the mainland at Port Pegasus had seen the Yellow Hammer, a species we were assured had arrived during the year of our visit.