Proc. Natl. Acad. Sci. USA Vol. 93, pp. 5296-5300, May 1996 Anthropo ogy

Late Holocene human-induced modifications to a central Polynesian island ecosystem (Pacific islands/archaeology/palynology/global change/island biogeography) PATRICK V. KIRCH Department of Anthropology, University of California, Berkeley, CA 94720 Contributed by Patrick V Kirch, January 23, 1996

ABSTRACT A 7000-year-long sequence of environmental change during the Holocene has been reconstructed for a TAVA tENGA central Pacific island (, ). The research design used geomorphological and palynological methods to - .~-~Z -\ reconstruct vegetation history, fire regime, and erosion and depositional rates, whereas archaeological methods were used to determine prehistoric Polynesian land use and resource exploitation. Certain mid-Holocene environmental changes are putatively linked with natural phenomena such as eustatic sea-level rise and periodic El Nifio-Southern Oscillation events. However, the most significant changes were initiated between 2500 and 1800 years and were directly or indirectly KEIA S B * associated with colonization by seafaring Polynesian peoples. These human-induced effects included major forest clearance, increased erosion of volcanic hillsides and alluvial deposition in valley bottoms, significant increases in charcoal influx, extinctions of endemic terrestrial species, and the introduc- tion of exotic species.

The assumptions that human (cultural) inputs to global change VEITATEI TAMARUA are primarily a modern phenomenon (i.e., -0.3 kyr; 1 kyr = TM7 thousand years) and stem from industrialization (1-3) are VT6 TIR- I 0 1 2km subject to test by archaeological investigation of preindustrial human/environment interactions over significantly longer FIG. 1. Map of Mangaia, showing concentric geological structure, time spans. The islands of Remote Oceania (4) are especially radial drainage pattern, and depositional basins (stippled). Core suited to such research because their ecosystems had generally locations are indicated by black dots. Reprinted with permission of evolved to steady-state equilibria, in isolation from continental Antiquity Publications, Ltd. biota (5-7). Humans (and other nonvolant vertebrates) did not reach Remote Oceania until 3.6-1.0 kyr, when seafaring, an age of 16.6-18.9 myr (1 myr = million years) for Mangaia's Austronesian-speaking peoples dispersed rapidly out of island volcanic core, which consists of ankaramite lavas (20). These Southeast Asia (8). Possessing a horticultural economy based are deeply weathered to laterite, with fresh rock exposed only on intensive root/tuber/tree crops augmented by marine in a few dike structures. Subcircular in outline (area 52 kM2), exploitation, Austronesians were skilled at interisland trans- the island has a concentric geomorphological structure (Fig. port of crop plants and domestic animals (9). Their technology 1), with a deeply weathered volcanic cone (maximum eleva- was limited to stone (basalt), shell, bone, wood, and fiber tion, 169 m) surrounded by a ring (0.7-2 km wide; maximum materials; fire was a major tool for agricultural clearance. This elevation, 70 m) of elevated, coralgal limestones of reef origin, report summarizes results from an interdisciplinary project called makatea (21). Fossil corals from the makatea cliff face that aimed to reconstruct a Holocene paleoenvironmental yielded 230Th/234U ages of 90-110 kyr and U-series ages of record for Mangaia Island and to assess the impact of colo- -115 kyr (22, 23). Rainfall runoff (1967 mm xi annual; ref. 24) nizing Austronesians. By analyzing stratigraphically controlled from the central volcanic cone has incised a radial drainage proxy measures for erosion, vegetation, burning, and terres- pattern, creating a solution escarpment along the makatea- trial biota, we may compare the prehuman ecosystem with volcanic interface (21). Sediments derived from the volcanic changes that occurred after human colonization. Specific case cone are deposited in basins at this interface (some surface studies have been published by project members (10-18); this water escapes through subterranean solution caverns in the article provides a synthesis. makatea, issuing below sea level along the coast; ref. 11). The potential for a deep Holocene stratigraphic record from these depositional basins was our main reason for selecting Mangaia. THE STUDY SITE: MANGAIA ISLAND The makatea escarpment also provided overhang rockshelters Mangaia Island (1570 55' E, 210 55' S) lies along the Cook- frequented by the Polynesian inhabitants of Mangaia, provid- Austral quasilinear volcanic chain, a magma plume trace ("hot ing a rich archaeological record of land use and resource spot" lineament) extending 2500 km from Macdonald Sea- exploitation (16). mount to (19). K/Ar dates on basalt indicate Vegetation cover is concentrically zonated as follows: zone 1, a littoral forest dominated by Pandanus, Guettarda, Bar- The publication costs of this article were defrayed in part by page charge ringtonia, and Hernandia trees; zone 2, where sufficient soil is payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact. Abbreviation: kyr, thousand years. 5296 Downloaded by guest on October 1, 2021 Anthropology: Kirch Proc. Natl. Acad. Sci. USA 93 (1996) 5297 present, a makatea forest dominated by Hernandia and Elaeo- 89 samples provide one of the most comprehensive suites of carpus, but strongly modified through cultivation of gardens radiometric dates for Holocene contexts on a central Pacific and tree crops (e.g., Cocos, Artocarpus, Aleurites); zone 3, island. where soil is absent, Pandanus scrub on pinnacle-karst makatea; zone 4, in the valley bottoms, a zone of intensive RESULTS cultivation including tree crops (e.g., Inocarpus, Cocos) and irrigated pondfields for taro (Colocasia esculenta); and zone 5, Holocene Stratigraphy. The 25 cores exhibit consistent blanketing the laterized volcanic cone, a pyrophytic associa- stratigraphic sequences throughout the main drainage basins. tion of fern (Dicranopteris linearis), scrub Pandanus, and The four facies groups present reveal significant changes in isolated Casuarina trees (25,26). Zone 5 was described as early depositional environments within the basins over the past -7 as A.D. 1777 (27) and appears to be a successional community kyr. (i) In cores TM4, TM7, IV1, KA3, and KA4, a pedogenic of anthropogenic origin. The modern terrestrial vertebrate mud was penetrated at 6-13 m below the modern land surface. fauna of Mangaia is depauperate, with only five landbird This basal facies represents an early Holocene land surface, species and six seabird species (18), a single, endangered fruit which began to be buried between 7260 ± 80 and 6450 ± 80 bat species (Pteropus tonganus), a few species of geckos and B.P. based on five 14C ages. (ii) After -7 kyr, this early skinks (introduced both by and Europeans), and Holocene paleosol was buried by thick deposits of black the Polynesian-introduced rat (Rattus exulans), chicken (Gal- (Munsell color 10 YR 2-3/1-2) lake peat (gyttja), indicating lus gallus), and pig (Sus scrofa). drowning of valley floors due to rapid post-Pleistocene sea Polynesians (a subgroup of the Austronesians) settled the level rise (31). Solution caverns in the makatea were open to and archipelagoes west of Mangaia by 3 kyr (28); the sea at this time, providing channels through which sea palynological evidence suggests that Mangaia was colonized by water could flood valley bottoms, creating brackish water lakes Polynesians between 2.5 and 1.6 kyr, whereas archaeological (11). This phase is marked by high spore concentrations of the materials directly document human habitation by 1 kyr. The brackish-water tolerant fern Acrostichum aureum (15). (iii) In Polynesian population was -3,000 in 1822, although Europe- most cores, lake peat deposition changed to red/brown (7.5 an-introduced diseases may already have reduced the popu- YR 3/4) reed peat in the upper levels, signaling the cessation lation significantly. Mangaian society was a variant of classic of Holocene sea-level rise; in TM4, the transition dates to 4000 Polynesian hierarchical chiefship in which warfare and com- ± 70 B.P. A mid-Holocene sea level stand of - + 1.1 m is also petition for limited irrigated lands were intense (29). indicated by elevated solution notches in the makatea escarp- ment of five drainage basins (10), matched by additional coastal evidence (32). (iv) The uppermost facies in all drainage MATERIALS AND METHODS basins is a reduced gray clay (5 Y 3/1) derived from the Stratigraphy and Palynology. Holocene stratigraphic records volcanic cone (mineralogical analysis indicates the presence of were obtained from 25 cores, sampling each of the seven main smectite, kaolinite, illite, and chlorite). The peat/clay transi- depositional basins (Fig. 1); maximum core depth was 15 m (in tion varies temporally between basins, but 14C ages of 1930 ± TIR-1, Veitatei Valley). Taken manually with Livingstone and 60 (IV1), 1830 ± 80 (VT5), and 1640 ± 80 B.P. (TM7) suggest D-section samplers, cores were x-rayed for microstratigraphy; the onset of a major phase of erosion on the central volcanic peat samples were selected for 14C dating. Core TIR-1 was cone at -1.8 kyr. For reasons indicated below, this onset of analyzed for bulk chemical composition by S. Dawson (University clay deposition correlates with human colonization and hor- of Hull, England) using x-ray fluorescence. An x-ray diffractom- ticultural land use. The clay facies vary in depth within each eter was used for mineralogical analysis; dithionite-extractable drainage basin, reaching up to 6 m in Veitatei Valley. iron was determined to measure free-iron content as a signal of In sum, the consistent stratigraphy indicates an island-wide weathering. Cores TIR-1, TM-7, and VT-6 were analyzed for sequence commencing with a stable (late Pleistocene?) land loss-on-ignition (at 550°C) and sampled for pollen analysis fol- surface that was inundated at lower elevations -7 kyr, due to lowing standard methods (30). Other aspects ofgeochemical and rapid post-Pleistocene sea level rise. As brackish lakes filled palynological analyses are presented elsewhere (10, 13, 15). valley bottoms, peat deposition dominated until the sea level Archaeology. Archaeological excavations were conducted in reached a mid-Holocene maximum (-+1.1 m above modern) seven rockshelter sites situated along the inner makatea es- at -4 kyr. At 1.8 kyr, a rapid change in depositional environ- carpment. Excavations followed chronostratigraphic units, and ment ensued, with clay in-filling of the valley bottoms. fine-sieving of sediments (through nested 12.8, 6.4, 3.2, and 1.6 Charcoal Influx. Microscopic charcoal particles were mm mesh) assured recovery of diminutive faunal and floral counted in samples from cores VT6 and TM7 (10). Micro- specimens. The rockshelters produced a cultural sequence scopic charcoal is absent below samples dated to 2570 ± 90 and from 1 to 0.2 kyr. Of particular importance to this study are the 2480 ± 60 B.P., whereas above these levels charcoal particles 35,157 bones obtained from site MAN-44 (16), providing a rich rise to peaks of 3 x 105 grains per cm3. The absence of record of human resource exploitation, particularly of birds microscopic charcoal in older samples indicates that natural and . Steadman and colleagues analyzed avifaunal remains fires were rare or absent in prehuman times. The onset of (16-18); fish bones were studied by V. Butler (Portland State microscopic charcoal after -2.5 kyr can be correlated with the University). The MAN-44 deposits also yielded invertebrate arrival of humans practicing slash-and-bum horticulture (13). remains (marine mollusks and echinoderms) and carbonized Core Sediment Geochemistry. Chemical analysis ofthe deep plant parts and wood charcoal (identified by J. Hather, Uni- TIR-1 core from Lake Tiriara revealed changes in the weath- versity College, London). ering regime of the central volcanic cone, as revealed in the Radiometric Dating. Accurate chronology was obtained sediment influx to the Veitatei Valley depositional basin (15); through extensive 14C dating. The stratigraphic cores were selected geochemical data for the upper 5 m of core TIR-1 are dated with 26 peat samples using conventional gas- graphed in Fig. 2. Significant changes include increases in sio2 proportional counting methods performed by Beta Analytic and A1203, along with free iron, and a decrease in P205. These (Coral Gables, FL) (10, 14), whereas the archaeological sites trends correlate with the pollen evidence indicating removal of were similarly dated with 40 samples of charcoal or other climax forest vegetation from the central volcanic cone, ero- organic materials (16). In addition, 23 samples of bone (in- sion of the thin organic soil horizon, and exposure ofthe deeply cluding extinct bird species) from rockshelter site MAN-44 weathered laterite. Organic content of all cores (determined were dated using the accelerator mass spectrometry facility at by loss-on-ignition) also drops steeply in the uppermost levels, Lawrence Livermore National Laboratory (Berkeley). These consistent with the above interpretation. Downloaded by guest on October 1, 2021 5298 Anthropology: Kirch Proc. Natl. Acad. Sci. USA 93 (1996)

35 7 and its replacement with successional femland. That this forest removal and replacement with a pyrophytic fernland/scrub Pan- 30 6 danus association resulted from burning is indicated by the high cO 25 5 charcoal particle influx for this same period (see above). 0 X 0) Wood Charcoal. An independent data set signaling vegeta- <520 41Lj tion patterns within the last 1 kyr is provided by carbonized 0e.15- x wood fragments from site MAN-44. Of 30 identified woody ;°a0 taxa, 29 occur in the basal occupation deposits (zones 2 and 3); a. -2 later deposits show a decrease in species diversity. There is a 57. marked decline in indigenous forest trees, such as Canthium barbatum, Fagraea berteriana, Geniostoma sykesii, Homalium 0 5 4 3 2 1 0 acuminatum, Myoporum sandwicense, and Sophora tomentosa. Depth Below Surface (m) The absence of these taxa in higher strata signals reductions in indigenous forest. The upper deposits (zones 6-17) are marked FIG. 2. P)lot of selected geochemical changes in the upper 5 m of by high frequencies of a few economically-important trees core TIR-1. (Aleurites moluccana, Cocos nucifera, Inocarpus fagiferus) and of Hibiscus tiliaceus, which dominates modern valley floors. Rates of Erosion and Deposition. As indicated by core The wood charcoal record thus provides a proxy measure of stratigraphy and geochemical analysis, erosion rates within the conversion of native forest cover to an anthropogenic Mangaia's radial drainage basins have changed significantly vegetation dominated by economically important taxa. during the last 7 kyr. From 7 to 2.5 kyr, deposition was largely Avifaunal Extinctions. An avifaunal record for Mangaia is organic (peat) with only thin, intermittent clay bands derived provided by 795 identified bird bones from the main excavation from short-term disturbances of the forest, probably by cy- block in site MAN-44 (16-18). Basal (culturally cryptic) zones clones and/or El Ninio-Southern Oscillation events (33). Such clay 1A and 1B represent a mid-Holocene period 14C (AMS) dated bands occur in cores IV1 and TM7 at 6500 ± 80 and 6480 ± 100 on 21 bone samples between -7.5 and 1 kyr. These basal B.P. After -1.8 kyr, however, large influxes of weathered clay sediments contain six species of seabirds (in the genera from the exposed volcanic slopes began to supplant peat depo- Nesofregetta, Phaethon, Anous, Gygis) and 14 species of native sition; in some valleys, clay deposits reached depths of 6 m. land birds, including rails (Gallirallus, Porzana), pigeons and Pollen Spectra. Pollen spectra were analyzed for three cores doves (Gallicolumba, Ptilinopus, Ducula), and parrots (Vini). from Veitatei and Tamarua (10, 15); the TM7 core is dia- Species diversity remains high in zones 2-4 (initial cultural use grammed in Fig. 3. They have a consistent sequence with a of the rockshelter) then plunges in zones 5-17 (the late major transition occurring between 2.5 and 1.6 kyr. Below this prehistoric period, -0.5-0.3 kyr). Of the 17 native land bird transition, the pollen spectra are dominated by indigenous species represented in MAN-44, 13 are now extinct or extir- forest taxa, such as Sophora tomentosa, Erythrina sp., Wein- pated on Mangaia (17). Of 13 seabird species represented in mannia samoensis, Ficus sp., and Cyathea treeferns. During the the site, 3 are extirpated, while all but two of the extant species transition, these and other forest taxa decline or disappear are currently endangered (<100 breeding pairs). This dramatic entirely, while three new taxa dominate: the monocot tree decline in avifaunal diversity during the period of human Pandanus tectorius and ferns Dicranopteris linearis and Cy- occupation of Mangaia (Fig. 4A) probably reflects both the closorus interruptus. Dicranopteris ferns dominate the laterized impact of direct predation (for food, feathers, and bone) as volcanic cone today, and their dominance in the pollen spectra well as habitat destruction, particularly forest clearance. A since 1.6 kyr signals the removal of indigenous forest vegetation third likely factor was predation by introduced rats.

cP X dpcb

1640+80 2. ±40+60 3270 + 70 3- 4- 4500 + 90 5 6 648 + 1007- 8- 7240 + 100 0 50 100 3 I. .* a 3 00 102100 200 300 XI10 _-mm 0 20 40 X103 Concentration Scale in Grains/cm2 FIG. 3. Simplified pollen diagram for core TM7, showing absolute concentrations of selected taxa, charcoal particle influx, and organic matter (%). Reprinted with permission of Antiquity Publications, Ltd. Downloaded by guest on October 1, 2021 Anthropology: Kirch Proc. Natl. Acad. Sci. USA 93 (1996) 5299

A carbonized stem, leaf, tuber or other parts (including wood 801 charcoal) from basal cultural zone 2 (-1-0.8 kyr) include aroids (Colocasia esculenta, Cyrtosperma chamissonis), banana c" 60 (Musa), breadfruit (Artocarpus altilis), Tahitian chestnut (Ino- E carpus fagiferus), sugarcane (Saccharum officinarum), ti (Cor- 0- v \ \ dyline terminalis), and sweet C,)co 40- potato (Ipomoea batatas); the latter is of South American origin (12, 16). Wood charcoal ,x demonstrates the early presence of tree crops, including Ino- v 20- - v Landbird Bone v. , carpus fagiferus, Artocarpus altilis, Cocos nucifera, and Syzy-

.~~~~ gium malaccense. Other introduced economic species include O- bamboo (Schizostachyum glaucophyllum) and candlenut (Aleu- rites moluccana). Pig (Sus scrofa), dog (Canis domesticus), and chicken (Gallus gallus) were all introduced as food items (Fig. 20 4B), although pigs were eliminated from the island in late prehistory. This set of adventive, economic species dominates the island's modern biota (25, 26). 1 C; I E Polynesians also introduced the Pacific rat (Rattus exulans), CI) 1 O a commensal species widely distributed throughout Oceania a- co 10- (34,35). R. exulans bones occur in zones lA-lB at site MAN-44 and throughout the upper, cultural deposits. Predation by R. ix 5. exulans on ground nests may have been an important factor in the decline of some flightless, native bird species. Another synan- 0 thropic species present in MAN-44 is the aquatic snail Thiara sp., 2-3 4 5-7 8 which thrives in irrigated pondfields, and may have been intro- Chronostratigraphic Zones duced with planting stocks of taro (Colocasia esculenta). Aquatic and Marine Faunal Changes. Although most of our FIG. 4. (A) Frequencies of landbird bones (NISP = number of data pertain to the island's terrestrial environment, some identified specimens) and species by chronostratigraphic zone in site materials from the MAN-44 deposits indicate marine and MAN-44. (B) Frequencies of pig (Sus) and chicken (Gallus) bones in aquatic changes over the past 1 kyr. Freshwater eels (Anguilla site MAN-44. sp.) and fish (Eleotrididae) were heavily exploited by the prehistoric Mangaians. High frequencies ofAnguilla in the early Human impact on the Mangaian avifauna is matched by deposits may correlate with more extensive lakes (and higher lake sharp declines in the frequency of another indigenous, volant levels) before 1 kyr. The impact of human gathering of mollusks species, the fruit bat (Pteropus tonganus). Pteropus bones are (for food and artifact manufacture) is exhibited for the reef common in the early levels of MAN-44 but become extremely gastropod Turbo setosus, the mean shell size of which declines rare in the upper deposits (18); the species persists but is significantly from early to later deposits (16). endangered on Mangaia today. Biotic Introductions. The MAN-44 sediments provide a record of biotic introductions, including economic plants, DISCUSSION domestic animals, and synanthropic (commensal) species in- Our interdisciplinary study of Mangaia enables a paleoenvi- troduced inadvertently. Introduced crop plants evidenced by ronmental reconstruction spanning the past 7 kyr, including 4NGAIA

100- 0- Polynesian 5 Forest Resource Arrival

80- 10- 4 %

a 350 c 0 0 .2. 20- x 60- .2 3 c a. .o c - 0 Charcoall -250 X 0 _ 75 L- 40. 30 0 2 C.3o -J _ 0 C a._ E 20- 40- _~_ _ Soil Erosion 0 1 I

- .00j 0 -50 t _~ ~ _I __I 0- 50] 0

I T I I I 5 4 3 2 1 6 Time Kyr B.P.

FIG. 5. Summary diagram of major changes in forest resource, soil erosion, charcoal influx, and human population over the past 5 kyr. Downloaded by guest on October 1, 2021 5300 Anthropology: Kirch Proc. Natl. Acad. Sci. USA 93 (1996) significant changes initiated through colonization and occu- 10. Ellison, J. (1994) Pacific Sci. 48, 1-15. pation of the island by Polynesians, between 2.5 and 1.8 kyr. 11. Ellison, J. (1994) Atoll Res. Bull. 417, 1-25. Fig. 5 summarizes some major trends over the past 5 kyr. 12. Hather, J. & Kirch, P. V. (1991) Antiquity 65, 887-893. Before the arrival of humans, the island was heavily forested 13. Kirch, P. V. & Ellison, J. (1994) Antiquity 68, 310-321. 14. Kirch, P. V., Flenley, J. R. & Steadman, D. W. (1991) Radiocar- and supported a diverse terrestrial biota including at least 30 bon 33, 317-328. species of land and sea birds. Natural fires were insignificant 15. Kirch, P. V., Flenley, J. R., Steadman, D. W., Lamont, F. & and erosion was limited to short-term periodic episodes asso- Dawson, S. (1992) Natl. Geogr. Res. Explor. 8, 166-179. ciated with cyclones and/or El Ninlo-Southern Oscillation 16. Kirch, P. V., Steadman, D. W., Butler, V. L., Hather, J. & events. Major environmental changes occurring during the Weisler, M. I. (1995) Archaeol. Oceania 30, 47-65. early-to-mid Holocene were lake formation and peat deposi- 17. Steadman, D. W. (1995) Science 267, 1123-1131. tion over Pleistocene land surfaces in the valley bottoms, 18. Steadman, D. W. & Kirch, P. V. (1990) Proc. Natl. Acad. Sci. USA resulting from rapid sea level rise. Polynesian arrival precipi- 87, 9605-9609. tated the following interrelated changes: (i) forest clearance 19. Wood, D. L. & Hay, R. F. (1970) Geology of the Cook Islands ( Geol. Survey, Wellington), Bull. 82. and conversion of central volcanic cone to pyrophytic Dicran- 20. Dalrymple, G. B., Jarrard, R. D. & Clague, D. A. (1975) Geol. opteris fernland; (ii) burning, with significant increases in Soc. Am. Bull. 86, 1463-1467. charcoal influx; (iii) increased rates of soil erosion, and alluvial 21. Stoddart, D. R., Spencer, T. & Scoffin, T. P. (1985) Zeit. Geo- infilling of valley bottoms; (iv) reductions in populations of morphol. 57, 121-140. native birds and fruit bats, leading to extinction and extirpation 22. Veeh, H. H. (1966) J. Geophys. Res. 71, 3379-3386. of many species; and (v) introduction of many economic plants 23. Woodroffe, C. D., Short, S. A., Stoddart, D. R., Spencer, T. & and domestic animals, along with certain synanthropic species. Harmon, R. S. (1991) Quat. Res. 35, 246-263. The Holocene paleoenvironmental sequence reconstructed 24. Thompson, C. S. (1986) The Climate and Weather ofthe Southern Cook Islands (New Zealand Met. Serv., Wellington), Publ. for Mangaia demonstrates that preindustrial, nonmetal using 188(2). horticulturally based human populations were capable of 25. Merlin, M. (1991) Pacific Sci. 45, 131-151. major, irreversible transformations to Pacific island ecosys- 26. Franklin, J. & Merlin, M. (1992) J. Veg. Sci. 3, 3-14. tems. The Mangaian sequence is not unique, and is matched 27. Beaglehole, J. C., ed. (1967) The Journals of Captain by evidence from such islands as Easter, Marquesas, , on his Voyages of Discovery: The Voyage of the Resolution and and (17, 36-43). Human impacts on terrestrial envi- Discovery 1776-1780 (Cambridge Univ. Press, Cambridge, U.K.). ronments clearly have a long history preceding the industrial 28. Kirch, P. V. (1984) The Evolution of the Polynesian Chiefdoms era (44). It will behoove those interested in understanding the (Cambridge Univ. Press, Cambridge, U.K.). "human dimensions of global change" to take account of 29. Buck, P. H. (1934) Mangaian Society (Bishop Mus. Press, Hono- lulu), Bull. 122. archaeological and paleoenvironmental records spanning at 30. Faegri, K. & Iverson, J. (1975) Textbook of Pollen Analysis least the full Holocene period. (Hafner, New York). 31. Nunn, P. D. (1994) Oceanic Islands (Blackwell, Oxford). I thank D. W. Steadman for critically commenting on a draft of this 32. Yonekura, N., Ishii, T., Saito, Y., Maeda, Y., Matsushima, Y., paper. I thank my project collaborators D. W. Steadman, J. Ellison, J. Matsumoto, E. & Kayanne, H. (1988) Palaeogeogr. Palaeoclima- Flenley, V. Butler, J. Hather, F. Lamont, and S. Dawson for sharing tol. Palaeoecol. 68, 177-188. their data and results. The Mangaia Project was supported by National 33. McGlone, M. S., Kershaw, A. P. & Markgraf, V. (1992) in El Geographic Society Grant 4001-89 and by National Science Founda- Niuo: Historical and Paleoclimatic Aspects of the Southern Oscil- tion Grant BNS-9020750; laboratory research on faunal materials was lation, eds. Diaz, H. R. & Markgraf, V. (Cambridge Univ. Press, supported by National Science Foundation Grant BSR-8607535 to Cambridge, U.K.), pp. 435-462. D. W. Steadman. The Cook Islands Government granted a research 34. Roberts, M. (1991) Pacific Sci. 45, 123-130. permit and the Mangaia Island Council facilitated our fieldwork. 35. Tate, G. (1951) The Rodents ofAustralia and New Guinea (Am. Mus. Nat. Hist., New York), Bull. 97. 1. Silver, C. S. (1990) One Earth, One Future: Our Changing Global 36. Bahn, P. & Flenley, J. (1992) , Earth Island (Thames Environment (Natl. Acad. Press, Washington, DC). & Hudson, London). 2. Stern, P. C., Young, 0. R. & Druckman, D., eds. (1992) Global 37. Flenley, J., King, S. M., Teller, J. T., Prentice, M. E., Jackson, J. Environmental Change: Understanding the Human Dimensions & Chew, C. (1991) J. Quat. Sci. 6, 85-115. (Natl. Acad. Press, Washington, DC). 38. Kirch, P. V. (1982) Pacific Sci. 36, 1-14. 3. Turner, B. L., II, Clark, W. C., Kates, R. W., Richards, J. F., 39. Kirch, P. V. & Yen, D. E. (1982) Tikopia: The Prehistory and Matthews, J. T. & Meyer, W. B., eds. (1990) The Earth as Ecology of a Polynesian Outlier (Bishop Mus. Press, Honolulu), Transformed by Human Action: Global and Regional Changes in Bull. 238. the Biosphere over the Past 300 Years (Cambridge Univ. Press, 40. Olson, S. L. & James, H. F. (1984) in Quaternary Extinctions: A Cambridge, U.K.). Prehistoric Revolution, eds. Martin, P. S. & Klein, R. G. (Univ. 4. Green, R. C. (1991) in Man and a Half: Essays in Pacific Anthro- Arizona Press, Tucson), pp. 768-783. pology in Honour ofRalph Bulmer, ed. Pawley, A. (Polynesian Soc., 41. Steadman, D. W., Vargas P. & Christino, C. (1994)Asian Perspec. Auckland), pp. 491-502. 33, 154-190. 5. Fosberg, F. R. (1963) in Man's Place in the Island Ecosystem, ed. 42. Steadman, D. W., Pahlavan, D. S. & Kirch, P. V. (1990) Bishop Fosberg, F. R. (Bishop Museum Press, Honolulu), pp. 1-6. Mus. Occ. Pap. 30, 118-153. 6. MacArthur, R. & Wilson, E. 0. (1967) The Theory of Island 43. Athens, J. S., Ward, J. V. & Wickler, S. (1992) New Zealand J. Biogeography (Princeton Univ. Press, Princeton). Archeol. 14, 9-34. 7. Williamson, M. (1981) Island Populations (Oxford Univ. Press, 44. Adams, R. McC. (1990) in The Earth as Transformed by Human Oxford). Action: Global and Regional Changes in the Biosphere over the Past 8. Kirch, P. V. & Weisler, M. I. (1994) J. Archaeol. Res. 2, 285-328. 300 Years, eds. Turner, B. L., II, Clark, W. C., Kates, R. W., 9. Kirch, P. V. (1994) The Wet and the Dry: Irrigation and Agricul- Richards, J. F., Matthews, J. T. & Meyer, W. B. (Cambridge tural Intensification in (Univ. Chicago Press, Chicago). Univ. Press, Cambridge, U.K.), pp. vii-x. Downloaded by guest on October 1, 2021