Santo edited by Philippe Bouchet, Hervé Le Guyader, Olivier Pascal The Natural History of N aturels

Publications scientifiques du muséum IRD ÉDITIONS

Patrimoines PRO-NATURA INTERNATIONAL The Santo 2006 expedition was organized, with the support, among others, of

and

Représentation de l'Union Européenne au Santo edited by Philippe Bouchet, Hervé Le Guyader & Olivier Pascal The Natural History of Foreword by Edward Natapei, Prime Minister of Vanuatu ...... 10

Introduction. The Natural History of Santo: An Attempt to Bridge the Gap between Academic Research and Consevation and Education ...... 11

Vanuatu in the South Pacific ...... 13 Benoît Antheaume

Espiritu santo in space and time ...... 17 coordinated by Bruno Corbara

The Late Quaternaty Reefs ...... 19 Guy Cabioch & Frederick W. Taylor The Holocene and Pleistocene Marine Faunas Reconsidered ...... 25 Pierre Lozouet, Alan Beu, Philippe Maestrati, Rufino Pineda & Jean-Louis Reyss Geography of Santo and of the ...... 34 Patricia Siméoni

Contents Drainage, Hydrology and Fluvial Geomorphology ...... 46 James P. Terry The Climate of Santo ...... 52 James P. Terry Large-scale Climatic and Oceanic Conditions around Santo ...... 57 Christophe Maes & David Varillon A Brief History of Biodiversity Exploration and Scientific Expeditions on and off the Island of Santo ...... 62 Bruno Corbara & Bertrand Richer de Forges Deforestation on Santo and Logging Operations ...... 67 Rufino Pineda The Impact of WWII on Infrastructures and Landscape ...... 69 Laurent Palka & Rufino Pineda Conservation Efforts in Santo ...... 71 Samson Vilvil-Fare vegetation and flora ...... 73 coordinated by Jérôme Munzinger & Porter P. Lowry II

Exploration by the Santo 2006 Botany Team ...... 75 Porter P. Lowry II & Jérôme Munzinger Principal Types of Vegetation Occuring on Santo ...... 76 Jérôme Munzinger, Porter P. Lowry II & Jean-Noël Labat Phytogeographic Relationships ...... 77 Gordon McPherson How Old are the Kauri (Agathis microphylla) Trees? ...... 83 Jonathan Palmer The Flora of Santo ...... 89 Some New, Characteristic or Remarkable Species ...... 89 Gordon McPherson & Jérôme Munzinger Focus on Araliaceae: Several Genera Exemplify Santo's Melanesian Biogeographic Relations ...... 90 Porter P. Lowry II & Gregory M. Plunkett Focus on Geissois (Cunoniaceae): Another Example of the Melanesian Connection ...... 93 Yohan Pillon Focus on Pandans ...... 94 Thomas Haevermans Focus on Orchids ...... 97 Marc Pignal

5 ... Contents ......

Focus on Palms ...... 102 Jean-Michel Dupuyoo Focus on Ferns ...... 105 Germinal Rouhan Focus on Bryophytes ...... 110 Elizabeth A. Brown Fungi, the Forgotten Kingdom ...... 113 Bart Buyck terrestrial fauna ...... 117 coordinated by Bruno Corbara

IBISCA-Santo Biodiversity Along an Altitudinal Gradient ...... 119 Bruno Corbara on behalf of the IBISCA network Insects on Santo ...... 123 Focus on Orthoptera ...... 123 Laure Desutter-Grandcolas, Sylvain Hugel & Tony Robillard Termites in Santo: Lessons from a Survey in the Penaoru Area ...... 128 Yves Roisin, Bruno Corbara, Thibaut Delsinne, Jérôme Orivel & Maurice Leponce Focus on Bees and Wasps ...... 131 Claire Villemant Myrmecophily in Santo: A Canopy Ant-Plant and its Expected and Less Expected Inhabitants 143 Bruno Corbara Beetles in Saratsi Range, Santo ...... 146 Alexey K. Tishechkin, Jürgen Schmidl Lepidoptera in Vanuatu: Fauna, Geography and the IBISCA-Santo Project ...... 155 Roger L. Kitching Other Invertebrates ...... 161 Diversity of Spiders ...... 161 Christine Rollard Some Arthropods as Expressed in the Words of Penaoru Villagers ...... 167 Bruno Corbara Indigenous Land Snails ...... 169 Benoît Fontaine, Olivier Gargominy & Vincent Prié The Vertebrates of Santo ...... 179 Terrestrial Bird Communities ...... 179 Nicolas Barré, Thibaut Delsinne & Benoït Fontaine Amphibians and Reptiles ...... 187 Ivan Ineich rivers and other freshwater habitats ...... 237 coordinated by Philippe Keith

Freshwater Habitat Types ...... 239 Philippe Keith & Clara Lord

Freshwater Biota ...... 242 Focus on Fish, Shrimps and Crabs ...... 242 Philippe Keith, Clara Lord, Philippe Gerbeaux & Donna Kalfatak

Focus on Aquatic Insects ...... 251 Arnold H. Staniczek

Focus on Freshwater Snails ...... 257 Yasunori Kano, Elen E. Strong, Benoît Fontaine, Olivier Gargominy, Matthias Glaubrecht & Philippe Bouchet

... 6 ...... The Natural History of Santo caves and soils ...... 265 coordinated by Louis Deharveng

The Karst Team ...... 267 Louis Deharveng & Anne-Marie Sémah Karst and Caves ...... 269 Bernard Lips, Franck Bréhier, Denis Wirrmann, Nadir Lasson, Stefan Eberhard, Josiane Lips & Louis Deharveng

Caves as Archives ...... 278 Denis Wirrmann, Jean-Christophe Galipaud, Anne-Marie Sémah & Tonyo Alcover, Ni-Vanuatu Perception and Attitudes Vis-à-Vis the Karstic Environment ...... 284 Florence Brunois Karst Habitats of Santo ...... 288 Focus on Soils ...... 288 Anne Bedos, Vincent Prié & Louis Deharveng Focus on Cave Terrestrial Habitats...... 296 Louis Deharveng, Anne Bedos, Vincent Prié & Éric Queinnec Focus on Guano ...... 300 Louis Deharveng, Josiane Lips & Cahyo Rahmadi Focus on Blue Holes ...... 306 Stefan Eberhard, Nadir Lasson & Franck Bréhier Focus on the Loren Cave ...... 310 Franck Bréhier, Sephan Eberhard & Nadir Lasson Focus on Anchialine Fauna ...... 312 Geoff Boxshall & Damià Jaume

Karst Biota of Santo ...... 316 Focus on Bats ...... 316 Vincent Prié Fish and Shrimps of Santo Karstic Systems ...... 323 Marc Pouilly & Philippe Keith Focus on Springtails ...... 327 Louis Deharveng & Anne Bedos Focus on Microcrustaceans ...... 331 Damià Jaume, Geoff Boxshall & Eric Queinnec

Marine Ecosystems ...... 335 coordinated by Philippe Bouchet

Benthic Algal and Seagrass Communities from Santo Island in Relation to Habitat Diversity ...... 337 Claude E. Payri The Position of Santo in Relation to the Centre of Maximum Marine Biodiversity (the Coral Triangle) ...... 369 Bert W. Hoeksema & Adriaan Gittenberger Focus on Selected (Micro)Habitats ...... 373 Sulfide Rich Environments ...... 373 Yasunori Kano & Takuma Haga Marine Interstitial ...... 375 Timea Neuser Mangroves Environments of South East Santo ...... 377 Jean-Claude Plaziat & Pierre Lozouet Focus on Selected Biota ...... 383 Checklist of the Fishes ...... 383 Ronald Fricke, John L. Earle, Richard L. Pyle & Bernard Séret

7 ... Contents ......

Unusual and Spectacular Crustaceans ...... 410 Tim-Yam Chan, Masako Mitsuhashi, Charles H.J.M. Fransen, Régis Cleva, Swee Hee Tan, Jose Christopher Mendoza, Marivene Manuel-Santos & Peter K.L. Ng The Marine Molluscs of Santo ...... 421 Philippe Bouchet, Virginie Héros, Pierre Lozouet, Philippe Maestrati & Rudo von Cosel A Rapid Assessment of the Marine Molluscs of Southeastern Santo ...... 431 Fred E. Wells Molluscs on Biogenic Substrates...... 438 Anders Warén Marine Partnerships in Santo's Reef Environments: Parasites, Commensals and Other Organisms that Live in Close Association ...... 449 Stefano Schiaparelli, Charles Fransen & Marco Oliverio Seaslugs: The Underwater Jewels of Santo ...... 458 Yolanda E. Camacho & Marta Pola

Man and nature ...... 465 coordinated by Michel Pascal

Pre-European Times ...... 467 Vertebrate Pre-Human Fauna of Santo: What Can we Expect to Find? ...... 467 Joseph Antoni Alcover

The Prehistory of Santo ...... 469 Jean-Christophe Galipaud Introduced Biota ...... 476 Overview: Introduced Species, the "Good", the "Worrisome" and the "Bad" ...... 476 Michel Pascal, Olivier Lorvelec, Nicolas Barré, Michel de Garine-Wichatitsky & Marc Pignal Focus on Synanthropic Mammals ...... 480 Olivier Lorvelec & Michel Pascal Focus on Feral Mammals ...... 483 Michel de Garine-Wichatitsky & Anthony Harry Focus on Alien Birds ...... 488 Nicolas Barré Focus on Introduced Amphibians and Reptiles ...... 490 Olivier Lorvelec & Michel Pascal Focus on Introduced Fish ...... 494 Philippe Keith, Clara Lord, Donna Kalfatak & Philippe Gerbeaux Focus on Alien Land Snails ...... 495 Olivier Gargominy, Benoît Fontaine & Vincent Prié Endemic, Native, Alien or Cryptogenic? The Controversy of Santo Darkling Beetles (Insecta: Coleoptera: Tenebrionidae) ...... 500 Laurent Soldati The Case of Two Invasive Species: Mikania micrantha and Merremia peltata ...... 503 Marc Pignal Man Santo in his Environment ...... 508 Food-Garden Biodiversity in Vanuatu ...... 508 Sara Muller, Vincent Lebot & Annie Walter At the Junction of Biological Cycles and Custom: the Night of the Palolo ...... 515 Laurent Palka Ni-Vanuatu Perceptions and Attitudes Vis-à-Vis Biodiversité ...... 516 Florence Brunois & Marine Robillard the santo 2006 expedition ...... 523 The Santo 2006 Expedition from an Ethnologist's Point of View ...... 525 Elsa Faugère

... 8 ...... The Natural History of Santo

The "Making of" Santo 2006 ...... 529 Philippe Bouchet, Hervé Le Guyader, Olivier Pascal

Santo 2006 Expedition in the Classroom ...... 549 Sophie Pons & Alain Pothet

Santo 2006 Expedition Participants List ...... 550 Acknowledgements ...... 553

Bibliography...... 557

Addresses of the Authors...... 564

9 ... in Bouchet P., Le guyader H. & pascal O. (Eds), The Natural History of Santo. MNHN, Paris; IRD, Marseille; PNI, Paris. 572 p. (Patrimoines naturels; 70). and Caves Bernard Lips, Franck Bréhier, Denis Wirrmann, Nadir Lasson, Stefan Eberhard, Josiane Lips & Louis Deharveng

The karst of Santo: geological setting Limestone facies account for almost topography has been interpreted as the initial stage half of the surface of Santo Island. The of a cone and cockpit karst landscape related to Papatai limestone is the most extensive over-deepening of preexisting depressions on the for-

Karst areally, covering c. 90 % of the karst mer lagoon floor. Numerous collapse features, many area east of a line drawn south from of them with maximum depths extending to more the mouth of the Jourdan River (see Fig. 325B in than 150 m below the surface, are asso- "Caves as Archives" by Wirrmann and coauthors). It ciated with the dolines. They are always associated overlies the Tawoli calcarenite-calcilutite formations with absence of roofing limestones over underground (ranging from middle Miocene to Pliocene), and streams. On topographical arguments, the related forms widespread plateaus in eastern Santo as well subterranean river courses have been considered as as isolated plateau remnants in the western part of very young features, younger than 60 ka BP. Collapse the island (for example the coastal plateau in Cape features are most pronounced in the areas where Cumberland). The Papatai formation consists of streams from the volcanic basement enter the limesto- massive Pleistocene coralline limestone, very porous, nes. Along the tectonic lineaments the allogenic rivers and made up entirely of high-magnesium calcite: it is were provided with paths of easier and faster pene- an uplifted complex of coral terraces and flat, coral- tration and solution so that extensive underground line islands. The coral terraces related to glacio-eus- channels could develop. On the isolated plateaus of tatic sea-level changes during late Pleistocene and the Luganville Surface west of Hog Harbour, north of Holocene time are constantly uplifted above modern and around the Walroul Plateau, collapse sea-level (see "The late Quaternary reefs" by Cabioch features are generally absent, while surficial solution & Taylor). The pure Quaternary reef limestones features are well developed, however. comprise the East Santo Plateau, its highest elevation being at 348 m in the Butmas Plateau.

The oldest Quaternary limestones, older than the last interglacial, present a pronounced residual karst mor- phology with well developed conical hills. They for- med at former reef crests and along interfluvial ridges on tilted limestone plateaus and terraces in the eastern central part of the island at Butmas Plateau, Mt Tanakar and Mt Tiouri. The conical hills have developed along the reef crests as the result of fluvial erosion perpendi- cular to the crests rather than through pure dissolution effect. Only in a few locations, more particularly at the northwestern end of Butmas Plateau, are conical hills associated with typical over-deepening of solu- tion dolines. The hills are most pronounced near the local base level of the Sarakata River, suggesting a fluviokarst morphology mainly related to erosional processes. Karst is totally absent in Tertiary calcareni- tes, where fluvial erosional forms dominate the relief, due to their high content of volcaniclastic impurities which induces better mechanical strength.

The last interglacial terraces (130-115 ka BP, Eemian Stage [1 ka = 1 000 years; years BP: before 1950]) form a broad compound terrace surface, termed the Luganville Surface. This formation exhibits a variety of solutional topography: small solutional and shal- low depressions (dolines) and residual hills, without large scale dissection into residual conical hills. This Figure 317: Karst (yellow area) and caves (red dots) of Santo.

269 ... Caves and Soils ......

The karst forms on the uplifted Holocene coral reefs tectonic uplift and a rising Holocene sea-level must correspond to circular or elongated collapse dolines have resulted in mainly vertical growth, which has of 4 to 6 m deep, sometimes extensive like at Hog overtopped a former and older submerged reef, Harbor and further north along the east coast and explaining how the extensive Holocene reef surface south of Mt Tomebou (See Fig. 325B in "Caves as could have formed in such a short time. Archives" by Wirrmann and coauthors). Most of them occur within a kilometre-wide strip parallel to This brief overview based on published works the coastline. Their development has been related to shows that, in combination with a perhumid tro- areas where subterranean water reaches the piezo- pical climate, the karst relief on the Quaternary metric surface near the present coast. Nevertheless, limestones of Santo is the result of facies-control- more especially between Mt Tomebou and Wambu led lithology and purity of parent material (lack of River, other depressions, which are not related to karst feature on the Tertiary calcarenite formation), collapse over underground streams, are also obser- tectonic conditions (the linear topographical fea- ved on this Holocene surface. Their origin probably tures defining preferential paths for vertical and reflects "premature" emergence of incomplete reef lateral solution), influence of soil and plant cover development, rather than a unique solution pro- (the deeper the soil, the stronger the dissolutional cesses like that of the Luganville surface. Rapid process) and Quaternary sea-level changes.

The caver perspective For cavers, the Santo karst is first a huge and com- Finding caves in Vanuatu can only be done in pact block of limestone, 60 km long by 25 km wide tight connection with local people. Not only the (Fig. 317), i.e. one of the largest karst blocks in the lush vegetation (Fig. 318) and absence of promi- Pacific. The few outlying islands and small outcrops nent landscape features would make direct pros- in the North and the West of the main island have pection long and uncertain, but also permission much less speleological potential. Elevation is mode- is mandatory for underground access, from the rate (784 m at the highest point, Mt Tanakar) and owner of the cave entrance and the tribal chief of undulating terrain is the dominant landscape, with the area where it is located. Local guides also are few large dolines and rare cliffs except along the necessary to reach the entrances, and young (and coast. The archetypical features of tropical karsts, less young) villagers often enthusiastically accom- pinnacles or steep karst towers, are absent in Santo. pany the cavers into the darkness. At least, in Nevertheless, the karst is amazingly rich in other karst many cases, sleeping in the villages is the best way features, including caves, deep dolines and large coas- to optimize the time spent underground — and is tal springs, enough to be very attractive for cavers. an unforgettable experience.

History of exploration The first cave explorations on Santo were done with large guano piles supporting abundant animal by Australian divers in search of sumps to dive communities in numerous caves. (1996-2000). They surveyed the large system Mt Hope-Sarakata resurgence (with a total horizontal A second preliminary reconnaissance targeting subter- development of about 3 400 m), and made the first ranean water habitats was made from 17 October to 13 trip to the Patunar giant doline. These pioneer November 2005 by Franck Bréhier, with three objecti- explorations were published in diving journals, ves: diving some inland caves to detect their richness in and remain little known among cavers. subterranean species; exploring karstic areas not seen by the preliminary reconnaissance, specially the northern In August 2005, Josiane and Bernard Lips and cape of the island; searching for anchialine habitats and Rufino Pineda, undertook a preliminary trip to fauna. In total, Franck explored 30 karstic features, of Santo, searching for biologically significant caves in which 10 potential anchialine habitats, 2 000 m cave the island in order to evaluate how much emphasis passages were recognized, and five caves were dived. should be placed on subterranean biology for the Aquatic fauna was present in most caves, and in several 2006 expedition. The results were beyond expecta- sites pottery as well as human bones were observed. tion, with 54 karstic features located (mostly caves) and 5 886 m of underground passages mapped. The Based on these promising results, we set up a strong most obvious biological features observed were the team of skilled cavers and divers to continue the omnipresence of bats, often in large colonies, and exploration and mapping of the cave systems of the the frequent occurrence of swiftlets, in association island, and to assist the biologists in the field.

...270 ...... The Natural History of Santo

A B E berhard L ips S . P hoto J. P hoto

C E berhard S . P hoto

D E L ips L ips P hoto B. P hoto B. Figure 318: Cave and shaft entrances. A: Lavav Aven near Port Olry. B: Avorani shaft on Malo. C: Bottom of Patunar doline. D: Patunar resurgence. E: Fapon Cave.

271 ... Caves and Soils ...... L ips P hotos B. Figure 319: Passing a "voûte mouillante" in Fioha Aven.

Main results The 2006 expedition allowed us to push explora- not mapped); tion and mapping of the caves recognized in 2005, • Riorua Cave (length: 400 m); but also to discover 28 additional caves or karstic • Tchawak Cave (length: 58 m); features. In one month, 13 961 m of subterranean • Patunar resurgence and doline (length: passages were explored, of which 7 961 m were 742 m). mapped. Eighty-six subterranean karstic features are recognized today on Santo: 10 blue holes, 41 The total known passages of the Funafus system caves less than 50 m length, 15 caves from 50 to reach 7 662 m, i.e. more than 1/3 of the total length 100 m, 21 more than 100 m, 12 more than 500 m of subterranean passages currently known from the and five more than 1 km long. With more than island. The Patunar doline is probably the most 19 km of explored underground passages in total, impressive karst surface feature of Santo: it is a Santo is the richest of the Pacific islands in number large depression with subvertical cliffs on three of caves and length of explored passages — outside sides, 100 m deep and 100-150 m in diameter. In New Guinea. sump In lowlands, most caves were dry entrances and did not give access to Tarius Cave underground streams, with the noti- ceable exception of the anchialine Loren Cave (see "Focus on Loren Tarius Aven cave"). Even the spectacular blue holes did not open onto significant sump P34 Riorua Cave underground passages. P12 spring Kafae Aven and sink sump The most interesting cave systems of the island were discovered in sump sump two upland areas: the Funafus area, which gave access to the largest caves of Santo, and the Butmas region, the most promising area, which was the most intensively studied biolo- gically. ……The Funafus system sump (Fig. 320) The largest subterranean system NM of Santo explored so far is located sump 2006 near the village of Funafus, between sump sump 100 and 250 m of altitude, in the southern part of the Santo karst. Funafus church Six caves, awaiting interconnection, belong to this complex: Tchawak Cave • Amont Cave (length: 259 m Patunar doline northwestern part of the system, not represented on the map); • Kafae Aven (length: 3 702 m); Patunar resurgence 0 250 m • Streamsink and Tarius Caves (length: 2 139 m mapped + 380 m Figure 320: The Funafus system (Funafus-Santo-Vanuatu, Santo 2006 expedition).

...272 ...... The Natural History of Santo

A P rié . V P hoto B C L ips P rié . V P hoto P hoto B.

D E L ips L ips P hoto B. P hoto J. Figure 321: Underground exploration. A, B: Underground river in large passages of the Kafae Aven. C: Descent in Kafae Aven. D: Amarur Cave. E: Fapon Cave.

273 ... Caves and Soils ......

A B L ips P rié . V P hoto P hoto B.

C D L ips P hoto B.

E L ips P hoto B.

F L ips L ips P hoto B. P hoto B. Figure 322: Underground exploration. A: Kafae Aven, clay formation. B: Calcite formation deposited by a little inlet in Kafae Aven. C & D: Stalactites in Fapon Cave. E: Stalactites and stalagmites in Fapon Cave. F: Amarur Cave, large fossil clam (Tridacna spp.).

...274 ...... The Natural History of Santo

Table 30: Longest (more than 300 m) and deepest (more than 25 m) caves of Santo and Malo Islands. Name of the caves length in m depth in m explored by Kafae Aven (Funafus) (Figs 321A-C & 322A-B) 3 702 -77 Santo 2006 Tarius Aven (Funafus) 2 139 -90 Santo 2006 Fapon Cave (Butmas) (Figs 318E, 321E & 322C-E) 1 400 -44 Santo 2006 Sarakata resurgence (Fanafo) 1 200 -30 Australians (Harris 2006) Loren Cave (Lotoror) 1 013 -40 Santo 2006 Mt Hope System: Fifty Four, Champagne Hole, Pump Sink, 900 -54 Australians (Harris 2006) Three Way Sink, Three sisters, Tourist Blue Hole (Fanafo) Amarur Cave (Nambel) (Figs 321D & 322F) 874 -21 Santo 2006 Mt Hope System: Drinking Hole, Clam Shell (Fanafo) 800 -67 Australians (Harris 2006) Patunar resurgence and Doline (Funafus) (Figs 318C-D) 791 -106 Santo 2006 Fioha Cave (Belmol) (Fig. 319) 550 -29 Santo 2006 Wanror (Butmas) 525 -40 Santo 2006 Mt. Hope System: Bush Rope Hole (Fanafo) 500 -36 Australians (Harris 2006) Millenium Cave (Nambel) 432 -41 Santo 2006 Riorua Cave (Funafus) 400 -25 Santo 2006 Mba Aven (Butmas) 387 -59 Santo 2006 Vobananadi shaft (Malo: Avorani) (Fig. 318B) 209 -87 Santo 2006 Lavav Aven (Loran) (Fig. 318A) 60 -31 Santo 2006 Tchawak Cave (Funafus) 58 -31 Santo 2006

the Kafae and Tarius shafts, the longest caves of aquatic: the last one, downstream of the third Santo recognized at this time, passages may reach doline gives onto a shallow sump 42 m-long. It up to 15 m wide by 15 m high with huge under- was dived during the last field trip of the diving ground streams. In several leads, exploration stop- team and gave access to a much larger and very ped simply by lack of time, or on big sumps (there different passage, with a big river running nor- were about ten, all of them easily divable). The thward, perpendicular to the first part of the cave, different parts of the system are likely interconnec- i.e. towards the Jourdain valley. Interestingly there ted by underwater passages, so future exploration were bats flying in this post-sump gallery indica- is now in the hands of divers, and probably would ting that another direct access exists to this part encompass more than 10 km of passages given the of the cave. Alone for this diving, Nadir Lasson number of galleries running in parallel. had to turn back by lack of time after 400 m of easy walk, after observing huge continuations ……Butmas: Fapon Cave and upstream and downstream. Mba Aven (Figs 323 & 324) The village of Butmas is set in the middle of Santo The same day, in the Mba Aven, another team in the jungle near the western border of the karst of cavers got access to another large river where and at the foot of Mt Tanakar. This area is over- exploration stopped upstream on a waterfall, and grown with dense secondary forest and tangled downstream on a winding, low ceiling passage. vegetation, and is the wettest of Santo. Several biological surveys were made in the largest cave of These last-day discoveries of major underground the area (Fapon Cave), which turned out to host a collectors highlighted the Butmas area as the rich and original fauna in its dark passages as well most promising site for future explorations in the as in its deep dolines which open on the course of Santo karst. Indeed, finding such big underground the subterranean stream. streams suggests that a huge network of hydrolo- gical passages are developed in the three or four The upstream entrance of Fapon Cave is a nar- hundred meters thick limestone terrain above row passage, where a small stream sinks among Butmas. The potential is even higher downstream, blocks. The subsequent galleries are moderate with suspected water resurgences at the coastal in size, some well decorated, and connect three blue holes, several kilometers away and more than successive deep dolines. Several passages are 300 m below).

275 ... Caves and Soils ......

?

? ?

sump: 42 m; -4 m 5 m

? 8 m -44 m 3 m sketchmap 7 m 10 m

Doline 3

7 m -25 m

sump -31 m

downstream sump doline 2 -21 m 2 m

doline 1 4 m -22 m

+-0 m sump P122 Fakir channel

shaft 2 m

4 m sump

2005

NM

-16 m sink 0 100 m

Figure 323: Fapon Cave (Butmas-Santo-Vanuatu, Santo 2006 expedition).

...276 ...... The Natural History of Santo

P34 NM 2005 -35 m

map 0 50 m R4 R4 section -43 m R4 0 50 m voûte P6 mouillante sump -59 m -49 m

P34

-35 m R3 -43 m R4 R4 voûte -49 m mouillante P6 sump -59 m

Figure 324: Mba Aven (Butmas-Santo-Vanuatu, Santo 2006 expedition).

The future of cave exploration in santo

One of the important and unexpected finding only a small part of what exists in the heart of the of Santo 2006 has been the existence of a well limestone, both in terms of length and depth of the organized underground drainage, with very large karstic features. Furthermore, we have no idea of underground passages in spite of the relative recen- the hydrological course of the largest subterranean tness of the karstification (younger than the Upper rivers discovered in Butmas: these questions are the Miocene). Kilometers of beautiful galleries have exciting challenge that Santo 2006 has raised for already been recognized, but they clearly represent future expeditions.

277 ... IRD ISBN MNHN ISBN 1281-6213ISSN Santo The NaturalHistory of : 978-2-7099-1708-7: in mind. world the over all from naturalists armchair as wellas stakeholders local with written was Santo conservation and education, Bridging the gap scientific between knowledge and "planet-island".this of biodiversity the to homage illustratedlavishly a is Santo of History Natural authors, 100 than more by contributions Withcountries. 25 from originating students and volunteers150scientists, over together brought ofthepast,Santo2006 expedition of discovery 3 back going habitation human of history a and islands, satellite mountains, caves, reefs, combining cosm, micro- cultural and geographical extraordinary an isVanuatu,Santo in highest and largest the tives: superla- of island an is Santo, as simply known affectionatelySanto, Espiritu floras. and faunas uniquetheir to, threats and of, endemism of levels The islands of the Pacific are renowned for the high : 978-2-85653-627-8: 000 years. In the spirit of famous voyagesfamous of spirit the In years. 000 9 The Natural History of 78 28 56 53 62 78 The

Prix : 59 : Prix monde entier. loppement et de l'éducation qu'aux naturalistes du ble. Il s'adresse autant aux acteurs locaux du déve- dura conservation sa pour connaissance de outil tifiques, richement illustré et bilan des connaissances scien- diversité de cette "île-planète". À la fois beau livre ce 100de auteurs, plus avec éditorial force de tour Petitpays. 25 de étudiants et bénévoles fiques, 150de scienti- plus terrain le sur mobilisé avait 2006Santo l’expédition Naturalistes", Expéditions à 3 à remontequi humaine occupation une et satellites, îlotset îles montagnes, grottes, récifs, avec rel, cultu- et géographique microcosme extraordinaire unest Vanuatu, Santo du haute plus la et grande plusla : superlatifs les cumule Santo, ou Santo, d'EspirituL'île flores. leurs de et faunes leurs de vulnérabilitégrande la et d’endémisme niveau Les îles du Pacifique sont célèbres pour le très haut Natural History of Santo est un éloge de la bio-

000 ans. Renouant avec l'esprit des "Grandesdes l'esprit avec Renouant ans. 000  The

TTC se veut unveut se Santo of History Natural -