The 1849 and 1851 specimens are usually said to have come from Resolution Island and Secretary Island respectively (e. g., Buller, 1888 and Oliver, 1955). As the species is flightless and the distance to be covered by swimming considerable, this seems most unlikely, and Mantell says the first specimen was “caught in the gully of a sound behind Resolution Island” (my italics). Hector (1863: 460) says he was told by one of the captors of the second specimen that it came from Deas Cove, on the mainland, and R. Henry (in Dollimore unpubl; p. 81–2) gives a verbatim account of its taking as well as that of two others (one from near Resolution Island) whose remains have apparently not been preserved. Only one complete adult specimen has been found since 1898. It was found dead in Takahe Valley in 1958.

Though the takahe first came to European attention through Mantell's discovery, it had been known to the Maori well before this in the southern part of the South Island for according to tradition, it was long hunted in parts of Fiordland (Beattie, 1949). In 1949 tradition was confirmed when a midden was found in Takahe Valley which contained takahe bones as well as those of other birds, including a species of bush moa (Duff, 1956). Radiocarbon dating of some of the associated material sets it in a period the middle of which is 1720 A. D. ± 60 years (Fergusson & Rafter, 1957). There seems to be no Maori legend explicitly referring to takahe in other parts of New Zealand, though subfossil and midden remains have been recorded from places mainly in the southern part of the North Island (Owen, 1872; Oliver, 1955; Greenway, 1958; Yaldwin, 1956; Falla, pers. comm.), and the eastern part of the South Island (Gurr, 1952). Reliable records for both islands are shown in Fig. 1.^* As some of the costal sites are middens they are only approximate guides to true distribution, for food was often carried for long distances.

Classification. On the North Island bones Owen founded Notornis mantelli. Meyer (1883) considered the skeleton from the 1879 specimen sufficiently different from the North Island bones to merit the founding of a new species, N. hochstetteri. But Forbes (1923) made public Parker's suggestion that the differences did not justify so great a separation. This opinion is in accord with modern ideas on taxonomy and has been endorsed by Peters (1934) and the New Zealand Checklist Committee (Fleming, et al. 1953), though Oliver remains staunch to the older view. Mayr (in Fleming, 1950) has suggested that Notornis and Porphyrio are congeneric, and Greenway accepts this opinion. In describing a new species of ectoparasite from the takahe, Rallicola takahe, Holloway (1955) remarks upon its close resemblance to the feather louse R. lugens, from pukeko, and suggests that this resemblance indicates that “N. mantelli and P. porphyrio melanotus are more closely related than at present indicated in the literature.” Although this view has much to commend it, the genus has been retained in the present paper. Notornis, then, is a genus endemic to New Zealand comprising two subspecies: N. m. mantelli, in the North Island, now extinct, and N. m. hochstetteri, in the South.

General Description, Weights, Sex Differences, Moults, Etc. Oliver (1955) and Buller give a detailed description of the adult N. m. hochstetteri. The following general account will thus suffice: The plumage has a loose and silky texture, that of the head, neck, breast, abdomen and thighs being indigo where exposed, but charcoal brown otherwise. Scapulars are peacock blue, changing to a metallic sage-green on the mantle Back, rump and upper tail coverts are olivegreen and the under tail coverts white. The primaries are indigo on the distal vanes but charcoal brown proximally. A striking contrast to the plumage is provided by the beak and legs—the former scarlet at the base and on the large frontal shield

Fig. No. 1

but becoming wax-pink distally; the legs and feet bright red. Eyes are reddish-brown. Though the species is flightless the wings are of a moderate size (length 243 mm, range 221–260 mm), and there is a spur at the carpal flexure. Colour plates appear in Buller—of these that in the earlier edition is the better—and in Rothschild (1907) and Oliver (1955). The last is a photograph of a living bird, but the reproduction of colour is poor. Rothschild's plate is the best in this respect.

Apart from its brighter and more varied plumage, the takahe is similar in general appearance to the pukeko, though much heavier (2–3 times), more robustly built and with shorter legs. Fleming (1951, 1958) has compared the general body structure of the adults of the two species particularly in regard to the differences in physiology, structure and function that arise through that of weight. There is no obvious sexual difference in the plumage and the bird stands about 20 inches (50 cm) high.

Fig. No. 3.—Scatter diagram showing sexual dimorphism of adults of N. m. hochstetteri.

Thirty-six living adults have been weighed and measured during the investigation and it has been assumed that—as in other of the Rallidae— the larger in a pair of birds is the male. By using either culmen measurements or weight the sexes apparently can be separated fairly accurately (Williams & Miers, 1958a) with but three exceptions, assumed males have culmen lengths greater than 87 mm and, with four exceptions, maximum weights greater than 2 · 60 kg. A scatter diagram

of culmen lengths and maximum weights shows only one male falling entirely within the assumed-female range (see Fig. 3). However, as this bird was mated with an even smaller one of culmen length 82 mm and weight 2 · 10 kg the assumption that it is a male seems justified. (The 1898 specimen—a sexed female (Benham, 1899a)—has a culmen length of 82 mm, and recently the bird found dead in 1958 was sexed by dissection and found to be a female, as presumed). The not very numerous records available of seasonal weight variations indicate for both sexes, over the time for which there are records, that weight is at a minimum about December, when the birds are busiest with nests and young (see Table No. 2). As the four assumed males with weights less than 2 · 60 kg have been recorded only at this time, this may be the reason for their lightness. In the absence of any other simple method for sexing takahe in the field, the present one seems satisfactory— that is, any yearling or adult whose weight is not greater than 2·60 kg, and whose culmen length is not in excess of 86 mm is a female, all others are males. It has been tested by seeing if such changes of mate as are known to have occurred involve the right sexes. No contradictions have yet appeared. A method for sexing the pukeko also dependent on culmen and weight measurements was checked by dissection and found to be 93.7% reliable (Williams & Miers, 1958b).

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Weights taken to nearest 0.05 kg; lengths to nearest mm.

The plumage sequences, now being studied in captive birds (Williams & Welch unpubl.) may be summarized as follows: The nestling is closely covered in black fur-like down except in the position of the future frontal shield where it is sparse. The bill is white from the external nares to the tip but black elsewhere. Legs are dark horn with a purplish tinge. At about one month down begins to be replaced by juvenile feathers to the tips of which it clings, and at about three months this moult is complete giving the juvenile plumage. Though similar to the adult, it is duller on head, neck, breast, mantle and back. The bill and developing frontal shield are almost black except for a paler tip to the upper mandible and the legs and feet are horn-coloured. A partial moult into a first winter plumage soon follows, the new feathers being mainly confined to the back and mantle. Though brighter than the juvenile they still lack the richness of those of the adult Legs and bill are now beginning to turn red, the former uniformly, the latter at the base and frontal shield only, elsewhere it is bluish-horn. The first summer plumage is still slightly browner on back and mantle than the adult, and the vanes of the distal primaries are greenish-indigo instead of the clear indigo of the adult, and although the rest of the bill has become pink there is still a bluish cast that is quite distinct. Yearlings and adults undergo a general post-nuptial moult which begins about mid-January and lasts throughout February and March. At this time takahe are quiet and secretive and large numbers of feathers are found under the shelter of tussocks, bushes or rocks where the birds have rested for long spells and aided the progress of the moult by plucking out feathers themselves.

Approximate weight at hatching is known from an embryo which died a few hours beforehand and was 61 grams. Twin chicks less than a week old weighed 96 grams and another set judged less than a fortnight old weighed 103 and 131 grams respectively. In captivity, three survivors of these four chicks reached the final stages of their body-weight growth curves at approximately seven months; wild young are in the adult weight range before they are twelve months old.

Internal anatomy has not recently been discussed. The skeleton of the nineteenth century specimens received considerable attention and detailed accounts with comparisons with related species may be found in Owen (1848b), Meyer (1833), and Parker (1882, 1886). Benham (1899b & c) studied the viscera— mainly the alimentary canal, larynx and syrinx. A recent observation of interest has been the great size and muscular development of the gizzard in both chick and adult. Benham, too, remarked on this in the adult he examined. He also published a paper (1899a) on the skin of the 1898 specimen. Recently Verheyen (1957) has given a general account of the characteristic morphology of the sub-family Porphyriinae to which Notornis, together with Porphyrio and Porphyrula, belongs.

N. m. mantelli is known only from bones. Those examined so far (Parker 1886, Yaldwin) suggest, surprisingly, that this race was larger than that from the colder South Island, but a more critical examination is necessary to take account of age and sex classes.

Since the above was written I have been able to compare the bones of the recent South Island adult female referred to in this paper with the skeletal material of extant and extinct forms held in New Zealand museums and with the full-scale plates of the Waingongoro bones described in Owen's original papers. There can now be no doubt whatsoever that the North Island subspecies was considerably larger than that from the South Island (as seemed fanly likely in any case from Oliver, 1955, and Falla in Greenway). However, leg bones from what is possibly

Fig. No. 1.— The Murchison Mountains area west of Lake. To Anau — the present range of
N. m. hochstetteri.

a single mature bird from the Martinborough Cave, North Island, fall within the size range of the South Island race and are smaller than any other North Island material. (The bones are held jointly by the Canterbury Museum, Christchurch, and the Dominion Museum, Wellington). The simplest explanation is that these belonged to an abnormally small adult N. m. mantelli.

Present Range. This includes the Murchison Mountains which lie between the Middle and South Fiords of Lake Te Anau, and part of the Kepler Mountains situated between the South Fiord of Lake Te Anau and Lake Manapouri (see Fig. 4). Though there have been occasional reports of takahe being seen elsewhere none has yet been confirmed.

Habitat. Most of the range is rough and mountainous. Peaks rise steeply to between five and six thousand feet and ridges and divides are kept narrow and jagged by the action of frost and snow. Streams are numerous and swift-flowing, there are many lakes and tarns and, in areas of poor drainage bogs. Rainfall is probably at least 100 inches a year with a sharply-decreasing gradient of intensity eastward and there is a heavy winter snowfall (Turbott, 1951). Below the treeline the dominant vegetation is evergreen beech forest, mainly Nothofagus menziesii (silver beech) and N. cliffortioides (mountain beech) with the degree of dominance of each varying from place to place. Above the forest is a band of subalipine scrub made up mainly of Dracophyllum uniflorum, Hebe buxifolia, and Olearia moschata. Above this again the tall tussocks are dominant—Danthonia flavescens and D. teretifolia on well-drained slopes and D. crassiuscula and D. oreophila elsewhere (Baylis, 1956, unpubl.). Rarely, but importantly as far as the takahe is concerned, tall tussocks are dominant well below the tree-line. When this is so the species most commonly occurring is D. rigida.

Takahe are generally to be found at about 3,300 to 3,800 feet where the forest has given way to scrub and snow tussocks—mainly D. flavescens. Occasionally tussock and scrub tongues run down through the forest to lower altitudes and takahe may then be found on these tongues. In winter and early spring, when snow lies thick on the tussock-covered mountain tops, the birds move into the forest until a thaw occurs.

Takahe Valley, where the species was rediscovered and where numbers are far more concentrated than elsewhere, is unusual in that the three-mile-long valley floor is fairly flat, wide and treeless (see Fig. 5); and although about five hundred feet below the tree-line (which here lies between 3,400 and 3,500 feet) it is, for the most part, covered in a luxuriant growth of red tussock, Danthonia rigida, with Festuca novaezcalandiae and Poa colensoi prominent among the grasses. In boggy places sedges (especially Cares spp.) are common. On each side of the valley floor forest-covered slopes rise steeply to the subalpine scrub and the tall-tussock meadows above. A stream collects much of the drainage of the upper valley and of the cuque at the head and meanders through occasional patches of bog to empty into a lake about 1,200 yards long and 250 yards wide situated at the lower end of the valley. The lake is drained by a stream which discharges through a gap in some limestone bluffs beneath which the takahe often shelter in the winter, and after a series of water-falls and caverns it finally reaches Lake Te Anau nearly 2,500 feet below.

The Point Burn, the area of next highest takahe concentration, lies immediately to the south and is separated from Takahe Valley for the most part by a low forest-covered ridge that rises between 300 and 400 feet. The valley of the Point Burn is typical of those in the Murchison Mountains and the rest of Fiordland in that it is narrow with its floor covered in beech forest except for an occasional clearing where mainly red tussock occurs. The lowest clearing in which takahe nest in this.

valley is at an altitude of about 2,400 feet and this is the lowest altitude at which the birds are known to continuously live and breed.

There is little doubt that distribution is correlated with that of the two species of tall tussock, D. rigida and D. flavescens, upon which the birds mainly depend for food, cover and nesting sites, and that the relatively dense population in the Takahe Valley—Point Burn area exists there because of the unusually favourable habitat. Baylis has made the general comment that “the wet Frordland mountains are botanically the least favourable part of the South Island for survival of the takahe since this is the region in which the large Danthonias are most extensively replaced at comparatively low altitudes by smaller species such as D. crassiuscula and D. teretifolia”. This then poses the problem of why takahe now exist only in this area and not also in apparently favourable ones elsewhere where the preferred species of Danthonia do occur.

Changes in Distribution and Possible Causes. Notwithstanding a tentative identification (Phillipps, 1959) of the legendary North Island “moho” or “mohoau” with the takahe, there is no clear reference to the species in Maori legends of the North Island and in those of the northern part of the South Island. This implies that it has long been rare or extinct there, and the fact that only subfossil or very old midden remains have been found supports this view. None of these have been accurately dated, but the midden material at Wairau Bar and Lake Grassmere has been assigned by Dufl to the Moa-hunter culture of 950–1550 A. D. and the rest is unlikely to be any more recent. Bones found at Pyramid Valley are associated with those of the large moas which became extinct before 1450 A. D., according to Duff. Inland deposits further south, for example, those at Earnscleugh and Castle Rock, show a similar association. Some, at least, of the Otago and Southland records are from middens—the one in Takahe Valley being dated, as we have seen, at approximately 1720 A. D. In none of the deposits so far critically examined have Notornis remains been abundant which implies that the species has not been common during the thousand or so years man has been in New Zealand. Only in western Otago are there reliable records of sightings in European and pre-European times, though Gurr (1952) accepts records given by Park (1888) implying a notable further shrinkage in range in this area within the last century. It is clear from present knowledge that Park's claims to have heard takahe are wrong. The acceptable records are Maori traditions which tell of hunting the birds in the mountains between Lakes Monowar are Te Anau, the evidence, gathered over the last eleven years, of the species' distribution in the Murchison and Kepler Ranges and the five specimens found before 1900. A rough parallelogram including Dusky Sound, Doubtful Sound, the Middle Frord of Lake Te Anau and the junction of the Whitestone and Mararoa Rivers delimits this recent range.

So early a scarcity of remains coupled with a major shrinkage in distribution exonerates all those suggested causes resulting from European settlement, such as habitat destruction, predation by—or competition with—introduced animals or epidemics from newly-introduced diseases. Any part played by the early Polynesians in hunting the birds or unfavourably altering then habitat has probably only accelerated a natural trend towards extinction. In this regard it should be remembered that the present population has survived in spite of being hunted until at least the beginning of the European era; and that even the presence during the last half century or so of possibly inimical exotic mammals such as stoats, red deer and Australian opossums does not seem to have had a detrimental effect. This may not be so in the future if the numbers of any of these mammals should greatly increase. Competition for food with any surviving native species is highly improbable because of the takahe's very specialized feeding habits. Whether any competion