FALLA: BIRDS AND l\1AMMALS 63 General pollen analysis may not be fruitful in elucidat- ing the history of this noble composite in the The luxuriant growth of O. lyallii, and Auckland Islands. the large numbers of young plants, with germination even in cracks in the bark of ACKNOWLEDGEMENTS prostrate trunks, have often been noted-for instance by Cockayne (1904) and Dorrien- I am very grateful to Dr. R. A. Falla for a vegetation map of Ewing Island on which Fig. 4 is based and Smith (1908). Although Cockayne could see for his interest in these problems; and to Mr. K. R. no reason why it "should not be the dominant West for preparing the illustrations. forest of the Southern Islands", O. lyallii has always been considered as fighting a losing REFERENCES battle in the Auckland Islands. To Dorrien- Smith (1908) it was swamped out by rata, CHAPMAN, F. R., 1891. The outlying islands of New Zealand. Trans. N.Z. Inst. 23: 491-522. "hence its disappearance from the main COCKAYNE,L., 1904. A botanical excursion during mid- islands"; to Cockayne (1904) it was perhaps winter to the southern islands of New Zealand. a relic of a former primeval forest, "ousted by Trans. N.Z. Inst. 36: 225-333. a new formation as the conditions changed"; COCKAYNE, L., 1907. In southern seas. The Auckland Islands. N.Z. Times, 11 Dee. and he also considered "that the tree in question COCKAYNE,L., 1909. The ecological botany of the sub- may have been a member of the now vanished antarctic islands of New Zealand. In The Sub- and problematical forest of an ancient antarctic Islands of New Zealand. Phil. Inst. of Antarctic continent" (Cockayne 1907; d. also Canterbury. COCKAYNE, L., 1927. New Zealand plants and their 1928: 174). story. 3rd. edn. Govt. Printer, Wellington. I suggest that O. lyallii is in fact increasing COCKAYNE, L., 1928. Vegetation of New Zealand. 2nd its area on the Auckland Islands, and that the edn. Engelmann, Leipzig. DORRIEN-SMITH, A. A., 1908. The southern islands present populations are derived from a rela- expedition. Kew Bull. 6: 239-249. tively recent immigration, probably in the early FALLA, R. A., 1948. The outlying islands of New Zea- 19th century, with Ewing 1. as the point of land. N.Z. Geographer 4:127-154. entry. From here, it is suggested, the species HOOKER, J. D., 1847. Flora Antarctica. Vol. 1. Reeye Bros., London. moved east to points around Ross Harbour, and HOOKER, J. D., 1867. Handbook of the New Zealand soutbwards along the coast (Fig. 5). Flora. Reeve & Co., London. The source of O. lyallii would probably be LEAMY, M. L., and BLAKEMORE,L. c., 1960. The peat soils of the Auckland Islands. N.Z. J. Agr. Res. 3: the Snares, the only other locality where it is 626-546. usually recognised as occurring. But when M'CORMICK, R., 1884. Voyages of discovery in the speculating on the history of this species it Arctic and Antarctic seas. Pt. 1. Sampson, London. should be recalled that specimens from Milford MOAR, N. T., 1958a. Contributions to the quaternary history of the New Zealand Flora. 1. Auckland Sound (Hooker 1867) and from Stewart Island Island peat studies. N.Z. J. Sci. 1: 449-465. and the Bluff (Cockayne 1927, 1928) have been MOAR, N. T., 1958b. Notes on the botany of the Auck. considered similar to or identical with O. lyallii. land Islands. N.Z. J. Sci. 1: 466-479. OLIVER, W. R. B., 1927. New Zealand's subantarctic As Moar (1958 a) mentions the difficulty of isles. Typescript held at Dominion Museum, Well- distinguishing O. lyallii pollen from that of ington. (Printed with modifications in the Evening the Pleurophyllums, particularly P. hookeri, Post, Wellington, 16 April 1927.) BIRDS AND MAMMALS OF THE SUBANTARCTIC ISLANDS R. A. FALLA Dominion .Museum, Wellington If comprehensive limits are allowed for a northern zone vvith some derivative sub- zone in the New Zealand area designated antarctic elements only and this is clearly 'Subantarctic', it would include the outlyers distinguisha ble from the middle zone which of Stewart 1., the Snares and the Chathams would include Auckland, Campbell, Antipodes in the north, and Macquarie I. in the south. and Bounty Is. The southern zone represented There is, however, a very mixed fauna in the by MacquCtrie is distinguishable again, its 64 ECOLOGY OF SUBANTARCTIC ISLANDS main elements being strongly circumpolar in land Islands, the so-called South Georgian affinities. For example, Macquarie has three diving petrel, which requires specialised con- genera of penguins found also in the Indian ditions for burrowing, appears to be on the and Atlanlic seclors of the Subantarctic and verge of exlinction. not otherwise found in the New Zealand Sub- antarctic as defined above. The sub-species Among the land birds, there are some of one of the mollymawks breeding at Mac- interesting differences between the islands. quarie is a circumpolar form and differs from The varied environment of the Aucklarid Is. an endemic race breeding at Cambell r. The can be correlated with a correspondingly same is true of the wandering albatrosses * varied avifauna. There are two endemic and the cormorants of these two areas so that waterfowl, the merganser, extinct, and the Macquarie may be excluded from the more flightless duck. In addition there are three descriptive part of this paper except for some self-introduced surface-feeding ducks, including comparisons. For the same reason Foveaux the mallard. There is even one endemic resi- Strait, the Snares and Chatham Is. are not dent shore bird, the Auckland Is. banded dealt with in detail. This leaves the other dotterel, and a small migrant population of four island groups for consideration. five or six wader species from the northern hemisphere. The two New Zealand birds of prey, the harrier and the falcon, are both BIRDS present. There have been one or more rails. Oceanic birds breeding in these groups show now probably extinct, and of New Zealand remarka ble uniformity except for the limits .forest birds, one flycatcher, two parakeets, two imposed and opportunities provided by varied honeyeaters and the ubiquitous white-eye. surface features and vegetation. Together with the pipit and six European Seventeen species of albatrosses and petrels passerines self-introduced from New Zealand are recorded as breeding at the Auckland Is. we are presented with a reasonably repre- About 15 of these also occur at Campbell 1. sentative land bird fauna. Modifying factors but almost certainly in reduced numbers conl- have been comparatively slight. The spread of pared with former abundance. Petrels at pigs, feral dogs, cats and probably rats at some Antipodes Is. are practically the same as on stage has rendered the main Auckland Is. Campbell 1., but the Bounty Is. have consider- unfavourable for the breeding of one or two ably fewer species. There are in fact no strongly vulnerable species, notably the snipe, the endemic races of petrels or penguins at any flightless duck and the red-fronted parrakeet, one of these four groups. The marine but there is extensive safe terrain for all these cormorants on the other hand have distin- on Adams I. and on several sizeable outlyers guishable endemic races at Aucklands, Camp- around Port Ross. It is a little more difficult bell and Bounty, while the very few cor- to account for the apparent extinction of the morants nesting at Antipodes have !lever been merganser. These birds undoubtedly bred in accurately identified. Petrels are, of course, the vicinity of numerous mountain streams in concerned with the land only for nesting and the gullies, depending for food on the local their density on the breeding areas is affected population of Galaxias and possibly supple- by many factors. At Antipodes disturbance has menting it with marine fish close inshore in never been very severe and birds are un- the fiords and harbours. It was certainly a doubtedly denser there than on any other target for hungry sealers and castaways but subantarctic island with the exception of the still survived at the turn of the century. Since Bounty. At Campbell Is. the ground has 1904 no trace of the merganser has been been considerably modified and breeding found. petrels are largely confined to remote and Campbell 1. lacks the varied vegetation and inaccessible outlying stacks. This modifica- the more complex terrain of the Aucklands tion on Campbell 1. has produced a more and it is not surprising that the essentially uniform vegetation which may have main- forest species of the Auckland Is. are lacking. tained a high population of the royal albatross. Grasstree (Dracophyllum) and tussock offer There is no evidence that any oceanic birds a restricted habitat and the extensive firing have become extinct within historic times as over many years and grazing of stock over so many evidently have at the Chatham Is.; but one of the two diving petrels at the Auck- ... Specific names of birds are given in Table 1. FALLA: BIRDS AND MAMMALS 65 nearly as many have produced conditions in demonstrations and the almost complete which only wide-ranging flocks of small absence of predatory skuas. This is clearly passerines can flourish. With few exceptions related to the effective 'umbrella' cover pro- these appear to be the more recent introduc- vided by the waving beaks of the thousands tions, white-eyes and the six or seven Euro- of mollymawks. No doubt there is interspecific pean passerines. There are a few pipits, adjustment between the mollymawks and the probably distinguishable as endemic, and a penguins but it is a relatively low premium flightless duck also a barely distinguishable for insurance against direct predation.