RECENT WORK ON THE CAVES OF TRINIDAD AND TOBAGO NOVEJŠE PREUČEVANJE JAM NA TRINIDADU IN TOB AGU JOHANNA P.E.C. DARLINGTON Izvleček UDK 551.442 (729) 591.542 (729) Darlington, Johanna P. E. C: Novejše preučevanje jam na Trinidadu in Tobagu Večina danes znanih jam na Trinidadu in Tobagu je bila odkritih do 1950, raziskane pa so bile predvsem V zadnjih treh desetletjih. Zaradi izbruha stekline je bila posebna pozornost posvečena preučevanju netopirjev, v zvezi z njimi pa tudi podzemeljskim jamam. V šestdesetih letih seje pojavilo vprašanje histoplasmose tudi v trinidadskih jamah. Po 1960 pa so pričenjali preučevati ptice tolstičnike (guacharo) iz znanstvenih in naravovarstvenih nagibov, kar je vzpodbudilo raziskave jam, med drugimi tudi deset let trajajočo ekološko študijo jamskega spleta Tamana. Ključne besede; speleologija, regionalne raziskave, netopirji, histoplasmosa, tolstičnik, zgodovina raziskav; Amerika, Zahodna Indija, Trinidad in Tobago Abstract UDC 551.442 (729) 591.542 (729) Darlington, Johanna P. E. C.: Recent work on the caves of Trinidad and Tobago By 1950 most of the Trinidad caves known today had already been discovered but the majority was explored in the last three decades. Due to an outbreak of paralytic rabies special atention was given to bats and thus, consequently, to cave exploration. In the 60s the problem of histoplasmosis appeared in the caves of Trinidad too. After 1960 the study of guacharos started mostly from scientific and natural conservation point of view arousing an interest for cave exploration, among others ten years lasting ecological study of Tamana cave system. Key words; speleology, regional researches, bats, histoplasmosis, guacharo, histoiy of explorations; America, West Indies, Trinidad and Tobago. Address - Naslov Johanna P.E.C. Darlington 21 Chesterfield Road Cambridge CB ILN England INTRODUCTION By 1950 most of the Trinidad caves known today had already been discovered. The process of exploration was far from continuous. Indeed a number of quite well-documented caves have become lost, as their locations have been forgotten. No systematic list has ever been published. Pawson, a sport caver stationed at Piarco Airport in 1945-46, wrote descriptions of all the caves known to hun, but his draft was never published in full (two short excerpts were published in 1974). Komisarcik (1979) made an independent attempt to hst the better known caves, reaching a total of 21. This is far fewer than were listed by de Verteuil and Urich (1936) for one small part of the island, but they were counting any activity that contained a bat roost, whereas Komisarcik only included caves large enough for people to enter. CAVE SURVEY AND EXPLORATION In 1974 a student from the Jamaica campus of UWI was employed by the Ministry of Planning in Trinidad to survey the caves in the Lopinot Valley with a view to developing them for tourism. His report (Aquing 1974) included brief descriptions and good maps with sketch sections of all the five known caves. This is certainly the best survey so far published of any Trinidad caves, but is not readily available. In 1978 four members of the Bloomington, Indiana Grotto of the National Speleological Society mounted their own small expedition to Trinidad (Komisarcik 1979; Wright 1979). They visited and made rough surveys of the Oropouche Cave, Caura Cave and the Tamana Caves, and drew up a list of other reputed caves in the island, but without quoting their sources (Komisarcik 1979). This was a very worthwhile effort (although some of the information was inaccurate) but these papers have remained largely unknown in Trinidad. At around the same time the Trinidad and Tobago Field Naturalists' Club (T&T FNC) took an active interest in caves during their monthly field trips. They surveyed the Oropouche Cave and part of the Aripo Main Cave, and estimated the numbers of oil-birds in each (Quesnel 1976, 1978b). The emergent river in the Oropouche Cave has stimulated much discussion and some field work. Stories are often told of ping-pong balls and other buoyant objects being thrown into the underground stream in Aripo Main Cave and later recovered from the Oropouche River, but these may be apocryphal. In 1964 two scuba divers, Adain Richards and Victor Abraham, attempted to dive through the syphon at the head of Oropouche Cave but drowned about 200 m upstream from the pool. The rescue party reported that the roof of the channel was unstable, and one of the bodies was trapped by fallen rocks. No subsequent attempt has ever been made. Members of the T&T FNC have made several unsuccessful attempts to locate a sinkhole marked on an old survey map 2 km West of the cave (Quesnel 1978a, c) which might be one source of the water. The hydrology of this whole limestone area still remains to be explored. In 1989 a cave was explored in the Aripo Valley of which no previous written record could be found, although it is clearly well known to local inhabitants. The cave contains a small colony of oilbirds. It was named the Soho Cave (Comeau 1991a) and a rough survey was made (still in manuscript). Another large cave nearby was explored by T&T FNC members in 1991 (Comeau 1991b). It fits the descriptiongivenby Carricker (1931) of cave in which he narrowly escaped a dangerous fall. There are likely to be other new caves in this area, and also in another heavily forested area of limestone in the mountains north of Matura. STUDIES ON BATS An outbreak of paralytic rabies occurred in 1932 in Trinidad, affecting livestock and humans. The disease was found to be transmitted by vampire bats, Desmodus r. rotundus. This provided a tremendous stimulus to cave exploration in the island (eg de Verteuil and Urich 1936), and also to studies on bats in general, the viruses they carry, and their associated ectoparasites and bloodsuckers. Taxonomic work on bats resulted in the publication of a monograph reporting 58 species to occur in Trinidad (Goodwin and Greenhall 1961). A more recent update lists 64 species (Carter et al. 1981). Much work has been done on the behaviour of vampire bats, and on methods to reduce their numbers (eg Greenhall 1968, 1970). Caves containing bat roosts were sought out, and in many cases the bats were needlessly destroyed where vampires formed only a small proportion of the bat population. It is now considered more efficient to catch the bats in mist nets when they approach livestock, or to poison them with a strychnine preparation pamted onto the skin of the host (Greenhall 1970). Control of vampire bats remains the responsability of the Veterinary Department of the Ministry of Agriculture. The feeding methods of the fishing bat Noctilio leporinus were studied by Griffm (1963). There have been several studies on reproduction in some cave-roosting bats (James 1977; Deoraj 1987) and on social behaviour and genetics in Phyllostomus h. hastatus in Guanapo Cave (McCracken and Bradbury 1977, 1981). A number of viruses have been isolated from the blood of bats, other mammals, and birds by the Trinidad Regional Virus Laboratory (TRVL), now called the Caribbean Regional Epidemiology Cenfre (CAREC). The same organisation has done a lot of work on arthropod vectors, including cave-dwelling species (e.g. Wirth and Blanton 1971). No disease is knovm to have been spread directly from cave-dwelling invertebrates to humans. although the potential exists. An example is the reduviid bugs Panstrongylus geniculatus in Tamana Dry Cave that were found to be infested with Trypanosoma cruzi, the causative organism of Chagas disease (Omah-Maharaj 1987). HISTOPLASMOSIS A different health problem associated with caves came to light in the 1960s. Histoplasmosis usually occurs as a lung disease resembling tuberculosis. The causative organism is a fungus Histoplasma capsulatum, which is commonly found in bird guano accumulated in communal roost sites or chicken houses, and also in guano deposits in bat caves. People who inhale the spores may suffer an accute form of infection called cave sickness or cave fever, which occasionally proves fatal. The flmgus was found to occur in some Trinidad caves associated either with oilbird colonies or bat roosts (Ajello, Greenhall et al. 1962; Ajello, Snow et al. 1962). Retrospective diagnoses were later made of some previously unidentified ilhiess associated with visits to the caves (Brown 1988). OILBIRD COLONIES Commercial interest in oilbirds as food waned in the earlier part of this centuiy, but scientific interest has intensified, culminating in a detailed study by Snow (1961, 1962) on the small nesting colony in a river gorge that is variously called the Arima Gorge, Spring Hill Cave, Dunstans Cave, or the Asa Wright Cave. Snow (1962) also listed all known oilbird colonies in Trinidad, eight of them active and five extinct. The Spring Hill colony is monitored regularly, once a year since 1969 (National Audubon Society Christmas bird counts) and quarterly since 1987 (Elias, pers. comm.). Numbers of birds in the Oropouche Cave and the Aripo Main Cave are estimated from time to time by members of the T&T FNC on their field trips (Quesnel 1976, 1978b, 1985). The colonies in the sea caves have not been visited for many years, and the exact locations of some of them are now uncertain. The species composition of the seeds regurgitated by the oilbu-ds (adults and young) in the cave at different times of year gave detailed information about the birds' food, and their role in dispersing plant seeds (Snow 1962). The plant debris thus brought into the cave, including seedlings that sprout from the regurgitated seeds where the cave floor is moist, provide the basis for a cave-dwelling biota of decomposer organisms and their grazers and predators, which has never been studied in detail. CAVE ECOSYSTEM STUDIES A combined project to study the bats, macrofauna and microbiota of the Tamana bat caves was planned in the late 1960s by Professor J.S. Kenny of the Zoology Department, University of the West Indies, Trinidad. In the event only the two latter topics were carried out at that time, and even they had to be localised in different parts of the cave because of the small size and fragility of the cave ecosystem. Only part of this work has been published. The Tamana Main Cave was mapped by J.S. Kenny and some of his students, omitting the deepest parts of the cave which still have not been explored. A brief description of the topography of the cave and an account of the atmospheric dynamics was published by Kenny (1978-79). A connection to the Tamana Dry Cave was explored in 1989 and the map extended (Fig. 1). Several new species of invertebrates were found in the caves, including a tineid moth (Davis 1972), a lygaeid bug (Scudder et al. 1967), a ptiliid beetle (Johnson 1969), a cetaropogonid fly (Wirth and Blanton 1971) and several other arthropods still to be described. The study of the macrofauna showed that the Upper and Deep Parts of the main cave were occupied by analogous but different species, the Upper Part (and the Dry Cave) being more diverse that the hot, wet Deep Part where most of the bat roosts were located. The fauna in the Deep Part was dominated by a blaberine cockroach Eublaberusposticus which is a guano eater and general scavenger. The biomass and energy dynamics of this population were studied in detail, both in the cave and the laboratory (Darlington 1970). The microbiota was studied in great detail in the Upper Part (Hill 1969). Compared with epigean soil the population densities were high (up to 19 times the highest previously recorded density for mites) but the number of species present was low. Guano of the fhiit-eating bat Phyllostomus h. hastatus was decomposed initially through a bacteria-nematode food chain, and later through fungus-mite food chains. Insectivorous bat guano was eaten by a cockroach Eublaberus distanti and also attacked by a fungus Penicillium janthinellum, which was then grazed by mites. A summary of the results was published by Hill 1981. CAVES IN TOBAGO Four small caves are known from near Crown Point in Tobago (Grady 1982). They were found to contain vertebrate fossils representing three distinct ages, and indicating changes in climate over the past 12.000 years (Eshelman et al. 1945). WORK IN PROGRESS AND PROSPECT Recreational visits to Trinidad caves continue, but a few people are more seriously interested in cave studies. T&T FNC members have been trying to re-locate some of the lost caves, and to improve the available information about the better known caves (Comeau 1991a, b). The Club has some basic caving equipment, but the level of caving experience among members is generally low. A bibliography of all published information on caves m Trinidad and Tobago is available in draft (from the present author) but is not yet complete. An attempt is being made to Tamana Caves, Central Range, Trinidad \ MAIN CAVE lirj}! DRY CAVE .vuc,-, chimney-kamin stream-struga approximate extent of chamber root - Unexplored - neraziskano približen obseg stropa dvorane trace all previous survey and sketch maps of the caves, although these vary greatly in quality. This will pinpoint which caves still need new or better survey work. Specimens of cave animals have been collected over many years by overseas visitors. Some were subsequently identified or described (eg Haas 1962), while others remam unreported in collections. New material collected over the past few years is currently being studied. Results of a student project on flies in the Tamana Main Cave have been published (Jennings & Darlington 1990). A short paper on cave craneflies is in press (Darlington & Gelhaus 1993-4), and a monograph on phorid flies is in preparation (R.H.L. Disney). The gradual increase in available information makes cave studies increasingly attractive to students and research workers. Table 1. Dimensions of some of the largest caves in Trinidad Cave name length Source of information Aripo Cave no. 1 853 m Gunther 1940 "no. 2 152 m a "no. 3 305 m it Aripo Soho Cave 70 m New survey, 1990 Oropouche Cave 214 m G.M. & L.M.Miller, Jan. 1960 it 225 m Quesnel 1976 it 215m Komisarcik 1979 Tamana Main Cave 130 m + J.S.Kenny, 1965 (incomplete survey) Tamana Dry Cave 50 m New Survey, 1989 Tabela 1. Največje jame na Trinidadu Ime jame dolžina Vir Aripo Cave no. 1 853 m Gunther 1940 "no. 2 152 m "no. 3 305 m Aripo Soho Cave 70 m Nov načrt, 1990 Oropouche Cave 214 m G.M. & L.M.Miller, Jan. 1960 (( 225 m Quesnel 1976 (( 215m Komisarcik 1979 Tamana Main Cave 130 m + J.S.Kenny, 1965 (nepopoln načrt) Tamana Dry Cave 50 m New Survey, 1989 REFERENCES Ajello, L. & A.M. Greenhall J.C. Moore, 1962: Occurrence of Histoplasma capsulatum on the island of Trinidad, B. W. I.: II. Survey of chiropteran habitats. Amer. J. Trop. Med.Hyg. 11 (2), 249-254 Ajello, L. & D. Snow & W.G. Downs & J.C. Moore, 1962: Occurrence of Histoplasma capsulatum on the island of Trinidad, B.W.I. : I. Survey of oil bird {Steatornis caripensis) habitats. Amer. J. Trop. Med. Hyg. 11 (2), 245-248 Aquing, F., 1974: Survey of Lopinot Caves. National Environment and Conservation Council Research Paper No. 1/74, Govt, of Trinidad and Tobago Ministry of Planning, 11 pp and 6 maps Carricker, M.A., 1931: The cave birds of Trinidad. Auk 48, 186-194 Carter, C.H. & H.H. Genoways & R.S. Loregnard & R.J. Baker, 198 h Observations on bats from Trinidad, with a checklist of species occurring on the island. Mus. Texas Tech. Univ., Occasional Papers 72, 29 pp. Comeau, P.L., 1991a: Frield trip to "Soho" cave on the 25"' November 1990. Bull T&T FNC, 2"" Quarter 1991,2-4 Comeau, P.L., 1991b: Rediscovering one of Carricker's caves. Bull. T&T FNC, 4"' Quarter 1991,2-3 Darlington, J.P.E.C., 1970: Studies on the ecology of Tamana Caves with special reference to cave-dwelling cockroaches. PhD. Thesis, Univ. of the West Indies, Trinidad, 224 pp. Darlington, J.P.E.C. & J.K. Gelhaus (1993-94 in press): Crane flies (Diptera: Tipulidae) in Trinidad caves. Living world (J. T&T FNC) Deoraj, P., 1987: The reproductive biology of the neotropical bats Carollia perspicillata, Anoura geoffioyi and Natalus tumidirostris. M.Phil, thesis, Univ. of the West Indies, Trinidad, 169 pp. Eshelman, R. & G. Morgan & F. Grady 1945: First records of fossil vertebrates (Quaternary) from the island of Tobago, West Indies (Abstract). NSS Bulletin 45 (2), April 1945 Goodwin, G.G. & A.M. Greenhall, 1961: A review of the bats of Trinidad and Tobago. Bull. Amer. Mus. Nat. Hist. 122, 191-301 Grady, F., 1982: The caves of Tobago: A preliminary account. The Potomac Caver 25 (8), 114-117. Reprinted in Speleo Digest 1982, 264-265 Greenhall, A.M., 1968: Bats, rabies and control problems. Oryx 9 (4), 263-266 Greenhall, A.M., 1970: Problems and ecological implications in the control of vampire bats. Proc. Latin Amer. Conf Cons. Renewable Nat. Res., San Carlos de Bariloche, Argentina, 27 March - 2nd April 1968, 7 pp. Griffm, D.R., 1963: The fishing bats of Trinidad. Animal Kingdom 66, 152-158 Gunther, A.E., 1940: Unpublished survey map of Aripo Caves 1, 2 and 3. By courtesy of the Archivist, TRINTOPEC, Point-a-Pierre, Trinidad Haas, F., 1962: Caribbean land molluscs: Subulinidae and Oleacinidae. No. 58, Fauna of Curacao 13, 49-60 Hill, S.B., 1969: The ecology of bat guano in Tamana Cave, Trinidad, West Indies. Ph.D. thesis, Univ. of the West Indies, Trinidad, 310 pp. Hill, S.B., 1981: Ecology of bat guano in Tamana Cave, Trinidad, W.l. Proc. 8* International Congress of Speleology 1, 243-246 James, C.J.W., 1977: Studies on reproduction in the female Neotropical bat Phyllostomus hastatus hastatus (Pallas) with observations on its general biology and ecology in Trinidad W.I. Ph.D. Thesis, Univ. of the West Indies, Trinidad, 282 pp. Jennings, G.M. & Darlington, J.RE.C., 1990: Flies in Tamana Cave. U.W.I. BioSpectrum 2, 4-8 Johnson, C., 1969: A new genus of Ptillidae (Coleoptera) from Tamana Cave, Trinidad. Entomologist 102, 145-148 Kenny, J.S., 1978-79: Floor plan, environment, and fauna of Tamana Caves. Living World (J. T&T FNC) 1978-79, 5-9 Komisarcik, K. /Editor, 1979: Caves of Trinidad issue. Bloomington, Indiana Grotto Newsletter 14 (2), 18-39, Feb. 1979. Reprinted in Speleo Digest 1979, 196-203 McCracken, G.F. & J.W. Bradbury, 1977: Paternity and genetic heterogeneity in the polygynous bat, Phyllostomus hastatus. Science 198, 303-306 McCracken G.F. & J.W. Bradbury, 1981: Social organisation and kinship in the polygynous bat Phyllostomus hastatus. Behav. Ecol. Sociobiol. 8, 11-34 Omah-Maharaj, I.R., 1987: Studies on the epidemiology of American trypanosomiasis in Trinidad. Ph.D. thesis, Univ. of the West Indies, Tmidad Pawson, K. Šs.a.Č: Explorations in the caves and potholes of Trinidad, W.L 1945-46 (with brief notes on the Barbados caves). Unpublished article, 58 pp. + 3 maps Pawson, K., 1974: Caving in Trinidad and Barbados. Canadian Caver 6, 21-26 Quesnel, V.C., 1976: Report on the trip to the Oropouche Cave on 7 March 1976. Bull. T&T FNC, 2"" Quarter 1976 Quesnel, V.C., 1978a: Field trip to the Oropouche Cave - 19"' March 1978. Bull. T&T FNC, 3'" Quarter 1978 Quesnel, V.C., 1978b: Field trip to the Aripo Cave on the 30"- April 1978. Bull. T&T FNC, 3"" Quarter 1978 Quesnel, V.C., 1978c: The search for the Oropouche Sink on 2P' May 1978. Bull. T&T FNC, 3'" Quarter 1978 Quesnel, V.C., 1985: Field trip to the CumacaCave on 28* April 1985. Bull. T&T FNC, 3^'' Quarter 1985 Scudder, E. & J.RE.C. Darlington & S.B. Hill, 1967: A new species of Lygaeidae (Hemiptera) from the Tamana Caves, Trinidad. Ann. Spel. 22 (2), 465-469 Snow, D.W., 1961: The natural history of oilbird, Steatornis caripensis, in Trinidad, West Indies. Part 1. General behaviour and breeding habits. Zoologica 46, 27-47 Snow, D.W., 1962: The natural history of oilbird, Steatornis caripensis, in Trinidad, West Indies. Part 2. Population, breeding ecology and food. Zoologica 47,129-139 Verteuil, E. de & F.W. Urich, 1936: The study and confrol of paralytic rabies fransmitted by bats in Trinidad, B. W. I. Trans. Roy. Soc. Trop. Med. Hyg. 29, 317-347 Wirth, W. W. & F.S. Blanton, 1971: New Neotropical sandflies of the Culicoides debilipalpis group (Diptera: Ceratopogonidea). Proc. ent. Soc. Washington 73, 34-43 Wright, M., 1979: Some inhabitants of Trinidad caves. Bloomington, Indiana Grotto Newsletter 14, 21-26, 8 Feb. 1979. Reprinted in NSS News 37, 76-78, April 1979 NOVEJŠE PREUČEVANJE JAM NA TRINIDADU IN TOBAGU Povzetek Večina danes znanih jam na Trinidadu in Tobagu je bila odkritih do 1950, vendar so slabo dokumentirane. Ta vrzel je bila v precejšnji meri zapokijena v zadnjih treh desetletjih. Zaradi izbruha stekline je bila posebna pozornost posvečena preučevanju netopirjev, v zvezi z njimi pa tudi podzemeljskim jamam. Žal so bile uničene cele kolonije jamskih netopirjev, čeprav so vampirji - prenašalci bolezni, predstavljali le majhen delež take kolonije. V šestdesetih letih seje pojavilo vprašanje histoplasmose in izkazalo seje, da so tudi v nekaterih trinidadskih jamah, kjer so kolonije netopiijev ali ptic tolstičnikov (guacharo), glive -povzročiteljice te bolezni. V zgodnjih letih tega stoletja so se ljudje zanimali za ptice tolstičnike predvsem kot vir prehrane, po 1960 pa so jih pričenjali preučevati iz znanstvenih in naravovarstvenih nagibov, kar je vzpodbudilo tudi raziskave jam, kjer so kolonije teh ptic. Oddelek za biologijo Zahodnoindijske univerze v Trinidadu je izpeljal tudi deset let trajajočo ekološko študijo jamskega spleta Tamana, kar je dalo vrsto objavljenih študij o jamskih netopirjih, makro- in mikrofavni. Avtor zaključi, da zanimanje zajame na Trinidadu in Tobagu raste, vedno večje zbranih podatkov in tudi vedno več zanimanja za nova preučevanja.