N.Z. ECOLOGICAL SOCIETY 17

Former Faunal Areas: Some Sub-Fossil Evidence

R. J. Scarlett.

Any discussion of former faunal areas described small Euryapteryx which I collect- based on the distribution of fossil or sub- ed on Stewart Island in Nov. 1954. Zelornis fossil bones is complicated when those bones haasti is known from Takaka, Canterbury, are of various geological ages. Nevertheless, Otago and Southland. study of the regions in which the genera and In the North Island, four closely related species of moa are found makes possible small species, Zelornis exilis, Euryapteryx some tentative conclusions. . curtus (Owen), E. tane, and E. geranoides The evidence is unevenly distributed be- are recognised. The first three range from cause some areas--the best sources are caves, N. Auckland to Wanganui and Napier, and swamps and sandhilIs--are better suited to geranoides from Tom Bowling Bay, N. the preservation of bones, or have been Auckland, to Takaka. better explored. The 'South Island Megalap- Emeus crassus (Owen) and Emeus huttoni teryx didinus (Owen) ranged down the west coast to Inangahua Junction, from Takaka (Owen) are known from Marlborough, and to coastal Marlborough, down the East are common in Canterbury and Otago. Coast to Southland and the Te Anau-Lake Pachyornis elephantopus Owen ranged from Wakatipu area. egegalapteryx benhami Takaka to Marlborough and from Canter- Archey is known only from the Nelson area. bury to Southland. P. murihiku Oliver was found near InvercargilI, and P. australis Anomalopteryx didiformis (Owen) has Oliver in Southland and Nelson. The-North virtually the same South Island distribution Island P. septentrionalis Oliver ranges from as Megalapteryx, but not as far west in Doubtless Bay (scarce) down the east coast Otago and Southland. In the North Island to Conoor and Martinborough, ndnd the west it is not uncommon in Wellington district, coast to Wanganui. P. mappini Archey is ranging up the east coast to Gisborne, is found in N. and S. Auckland, Coromandel found at Coromandel Peninsula, Whangarei, Peninsula, Gisborne, New Plymouth, and the up the west coast, and in southern Auckland. east and west coasts of Wellington. The smaller Anomalopteryx oweni (von Haast) is most common in North Auckland, Dinornis maximus von Haast is common but is known from Te Aute swamp (Hawkes in Canterbury, Otago and Southland. D. Bay), Martinborough (Wellington) and robustus Owen is found from Takaka to around Wanganui. As Euryapteryx and Marlborough, down the east coast to South- Z elornis can only be separated if the skull is land, over to L. Wakatipu, and Jackson's present, possibly some Euryapteryx gravis Bay, west coast. D. torosus Hutton had a (Owen) records may be of Z elornis haasti similar distribution to robustus and reached (Rothschild) ,and some Euryapteryx tane Rahu, west coast. Oliver may be of Zelornis exilis (Hutton). The North Island D. giganteus Owen is In the South Island, Euryapteryx gravis uncommon, found mainly from Poverty Bay predominates, from Takaka to Marlborough, southwards on the east coast, and from down the eastern side of the Alps to Stewart Wanganui southwards on the west, being Island, and westward to L: Wakatipu, and most plentiful in the Wellington district. in the North Island, up the east coast to L. The Doubtless Bay records may be of D. Waikaremoana. Bones from Papatowai, hercules Oliver, also mainly found in south- Southland, formerly classified as the North ern North Island. D. ingens. Owen, found Is. E. geranoides (Owen) belong to an un- throughout the North Is., is more common - 18 N.Z. ECOLOGICAL SOCIETY

in the southern part. South Island legbone Cook Strait land bridge up the east of the records refer to robustus. North Is. Volcanic ash showers obscure the It now remains to discuss the significance evidence in the central North Island, but of this distribution. Fleming's map (1949) Zelornis exilis, Euryapteryx cortus and E. of his interpretation of the paleogeography tane came from north of the Manakau Strait, of New Zealand during the early Whanganui spreading southwards when it closed. E. Period, shows a small strait flooding the geranoides probably originated as a species Manakau lowlands, near Auckland, and a between the Manakau and Manawatu Straits, much larger Manawatu Strait running later spreading north and south. roughly along a line below New Plymouth Emeus, closely related to Eur'yapteryx, is to below Gisborne, and Cook Strait closed confined to eastern South Island, and Pachy- on the eastern side. ornis elephantopus to that area and Nelson- Takaka. P. mappini and P. septentrionalis Moa origins are unknown. It is possible originated either in North Auckland or mid- that the. Dinornis group had a different North Island. Anomalopteryx didiformis ancestry from the other six genera. Prob- originated south of the Manakau Strait, ably before the Waitotaran stage Dinornis (fragmentary A. antiquus Hutton from had diversified into three size groups, and Timaru is very close to it). A. oweni be- during the existence of the Manawatu Strait came distinct north of Manakau Strait. the maximus-giganteus and hercules, robus- Thus the three main moa faunal areas tus-ingens, t0r'osus-novaezelandiae pairs de- (see map) are (A) North of Manakau veloped. Strait. (B) Central North Island. (C) Original Euryapteryx stock was probably South Island, mainly east of the Alps, from mamall, but E. gravis and Zelornis haasti be- Takaka to Stewart Is., and, for E. gravis, came dominant in the South Is., leaving Eastern North Island. The distribution of marginal small forms in the south (Stewart D. maximus is shown by the dotted line. Is. was then joined to the mainland) and in REFERENCE the North Is. E. gravis spread over the FLEMING C. A., 1949: Tuatara 2(2): 72-90.

, Discussion

THE CHAIRMAN opening the discussion subsequently the whole area being re-colon- said the problem was to try to establish ised and the forest advancing as the ice face some community of pattern in the various disappeared and moved south; it was possible ecological and biological factors present in that some species found the only suitable the areas propounded as natural and see to conditions in the regenerating forest follow- what extent it was possible to make broad ing on the disappearing ice sheet; certain of delineations of these areas Various points them perhaps stayed behind and adapted had emerged from the papers: the apparent themselves and others carried on, following significance of the 38th parallel; the effect the retreating ice. For a long time it was of Cook Strait, which is a barrier to certain believed that glaciation was the key to the reptiles 'and some of the birds, but not to distribution of Paryphanta, but if the geo- worms. logists were right and the South Island was fairly devoid of this type of life it was a MR. DELL, answering a question on the dis- hard situation to envisage. continuous distribution of snails, said that some could be partly explained on the geo- MR. SCARLETT said the survival of certain logical evidence but the geologists' plans of groups of opilionids in Fiordland suggested the post-pliocene area in New Zealand were that high country there was not as severely rather indefinite. If Wellman's theory of glaciated as some geologists thought. glaciation in New Zealand was accurate one MISS L. B. MOORE commented that the had to envisage everything being pushed up effects of glaciation might have been over- from south to north by advancing ice, and emphasised and mentioned that earthworms 22 N.Z. ECOLOGICAL SOCIETY KEYS TO CLIMATE AND SOIL MAPS MAIN CLIMATIC DISTRICTS westerlies giving temperatures above 90'F, cool (See map) winters with frequent frosts and occasional light snowfalls. .Prevailing winds NE near the coast, A. Very warm humid summers, mild winters. NW inland. Annual rainfall 45-60 inches with maximum in F. Cooler and wetter hill climates. Rainfall 30-60 winter. Prevailing wind south-westerly but oc- inches. NW winds prevail with occasional very casional strong gales and heavy rain from east strong gales specially along river courses. Snow or northeast from Auckland northwards and may lie for several weeks in winter.. about Coromandel Peninsula. F, Semi-arid areas, rainfall 13-20 inches. Very A. Similar to type A but much wetter: rain- warm, dry summers; cold winters. 60-100 inches. G. Warm summers, cool winters. Rainfall 25-35 B. Sunny, rather sheltered areas which receive inches, evenly distributed except for slight fall- rains of very high intensity at times from the ing off in winter. northeast and north. Very warm summers and G. Wetter and slightly cooler than G climates: mild winters. Annual rainfall 40-60 inches rainfall 35"50 inches: in coastal districts cloudy, with maximum in winter. windy conditions and frequent showers. C. ' Very warm summers, tempera,tures occa- M. High rainfall, mountain climate. sionally above 90¡F withdad,ry Foehn NW wind blowing. Rainfall 40-60 inches per annum: marked decrease in amount and reliability of "NATURAL AREAS" OF NEW ZEALAND SOILS. rain in spring and summer: moderate winter (Boundaries generalized from Soil Map of N.Z. temperatures with maximum rainfall in this 1948.) season. SOILS IN WHICH THE ENVIRONMENT IS Co Drier than type C-rainfall 25-35 inches. Very FULLY EXPRESSED: sunny. 1. Soils of the cool semi-arid zone, developed under C. Cooler and wetter hill climates. Very heavy tussock grasses. rains at times from east or southeast: annual 2. Soils of the mild sub-humid zone developed rainfall mainly 60-80 inches. mainly under tussock grasses. D. "est to northwest winds prevail with rela- 3. Soils of the humid zone developed mainly under tively frequent gales. Mean annual rainfall forest. 35-50 inches: rainfall reliable and evenly dis- SOILS IN WHICH THE ENVIRONMENT IS NOT FULLY tributed through the year. Warm summers, mild EXPRESSED, DUE TO THE DOMINANCE OF CERTAIN winters. FACTORS: D, Wetter than D-rainfall 50-80 inches. 4. Skeletal soils on steep slopes dominated by the E. Mild temperatures, high rainfall increasing topography factor. rapidly inland with height, minimum rainfall in 5. Recent soils from alluvium or volcanic ash, winter especially in the south. Prevailing winds domina,ted by their youth-the time factor. SW but gales not f~requentat low levels in spite 6. Soils from old volcanic ash, dominated- by their of exposed coastline. abnormal parent material. F. Low rainfall, 23-30 inches: in the south 7. Soils from younger volcanic ash, dominated by slightly more in summer than in other seasons. their youth and their abnormal parental ma- Warm summers with occasional hot Foehn north- terial. Excursion On Saturday, May 12th, there was an season was in progress considerable numbers excursion by bus from Wellington, over the of waterfowl were seen. A stop was made Rimutaka Range, to the southern portion of at this point for lunch. the Wairarapa district. 4. Top of hill above Lake Onoke: From During the excursion stops were made at this point an excellent view was obtained of the following places: Palliser Bay, Lake Onoke, which is separated 1. Summit of Rimutaka Range: Mr. A. L. from the sea by a long narrow shingle spit, Poole and Mr. A. P. Druce pointed out fea- Lake Wairarapa,and the southern portion tures of the vegetation, which consists of of the Wairarapa district, bounded on the scrub (manuka and some sub-alpine species) east by the Aorangi Range. and remnants of the red beech and silver 5. Lake Onoke: Most of those present beech forest which formerly covered the walked along the narrow spit and examined area. contrasting conditions on the seaward and landward sides. 2. Western Lake Forest Reserve: Beech From Lake Onoke the bus returned to forest here comes down to the edge of Lake Wellington over the same rGute. Commen- Wairarapa. Mr. Poole and Mr. Druce ex- taries on points of interest near the road plained some features of the forest. were given throughout the excursion by vari- 3. Lake Pounui: This is a small lake which ous members, using the loudspeaker system is a bird sanctuary, and since the shooting in the bus,