An observational study of Nusa Penidas Herpetofauna: A preliminary examination of the islands biodiversity

Transcription

1 An observational study of Nusa Penidas Herpetofauna: A preliminary examination of the islands biodiversity Research completed on behalf of FNPF by Sami Asad, 28/10/2011 Abstract The Friends of the National Parks Foundation (FNPF) have recently been attempting to implement a biodiversity monitoring program through its field center on the island of Nusa Penida. At this moment there is little baseline data concerning the islands fauna and flora due to a lack of previous research. Therefore, an examination of the islands herpetofauna will not only provide records for species presence and biodiversity, but will also provide a preliminary assessment of habitat health and ecosystem viability. As such the purpose of this study is to carry out a brief habitat assessment of the island in relation to specific study areas and then survey said areas for herpetofauna thus providing a database for their presence and distribution, as well as providing a measure of biodiversity and habitat health. 1

2 Contents 1. Introduction Project outline Nusa penida Project overview Objectives Applications Methods Habitat assessment Vegetation types/diversity Anthropogenic disturbance Elevation Soil quality Hereptofuana diversity survey Results Habitat assessment Herpetofauna diversity surveys Discussion Habitat assessment Savannah

3 4.1.2 Plantation Scrubland Tropical monsoon forest Tropical rainforest Wetland Conclusion Herpetofauna diversity surveys Amphibians Reptiles Lizards Snakes Conclusion Acknowledgments References Appendix..27 3

4 Introduction With the assistance of FNPF the aim of this particular study is to carry out a herpetofauna species survey and undertake a basic habitat assessment of the island. The overall aim of which is to create not only a database of herpetofauna species present, but also provide a better understanding of the islands biodiversity. As the islands flora and fauna have been poorly documented little is known concerning its biodiversity and at present there is no definitive species database. As such if further wildlife studies and conservation programs are to be implemented there must first be a biodiversity and ecological census initiated to provide baseline data for future projects. Project outline This study seeks to examine the reptile and amphibian species present as well as defining and identifying the various habitat types of the island and their relative herpetofauna diversity. Without which information, future studies and conservation implementations would be impossible. The studies emphasis is primarily concerning herpetofauna as various organisms within this group provide excellent environmental indicators. Ideally, in a rich tropical environment with little species knowledge one would focus ones indicator species on larger mammal species with fairly demanding ecological requirements (Sunderland 2006). However due to the islands poor size and fairly impoverished natural habitats mammal diversity is likely to be poor. In fact only a handful of species have ever been recorded on the island and these have been identified by unconfirmed sightings. The islands reptile and amphibian species however seem to be present in some numbers, and groups within these classes should provide ample information concerning habitat health. Within the reptilian group, the presence of many snake species is indication that specific prey items (small mammals, other reptiles and amphibians, birds, invertebrates) 4

5 are in relative abundance, with the amphibian presence indicating water quality(noss 1990). The secondary aim and arguably the most important of the project is identifying and outlining the major habitat types on the island. Once these areas have been measured in terms of vegetation types/diversity, soil quality and anthropogenic influence a further habitat type database can be compiled which will serve as baseline habitat information for more in depth biodiversity monitoring and species specific research. Also, the outlining of habitat types can be used to further assist conservation projects on the island. Infact, once the survey outlines suitable habitat the FNPFs reforestation program could be implemented on such sites throughout the island thus improving habitat health. Nusa penida The island of Nusa Penida lies 14km SE off the coast of Bali and is a branch of the Klungkung regency. The island is a typically dry habitat with rolling hills cleared of vegetation and predominantly used for agriculture. Despite its proximity to mainland Bali, Nusa Penida and its two neighboring islands (Nusa Ceningan and Nusa Lembongan) originated as coral islands as opposed to Balis volcanic origins. This coupled with its significantly lower annual rainfall has led to the islands poor soil quality and apparent dry and barren qualities (Giambelli 1999) Although the island is significantly dryer than Bali it has not always been devoid of vegetation. In fact the areas surviving primary forest are believed to be remnants of forest which once covered the majority of the island. These areas are believed to have begun being cleared over 4oo years ago by convicts exiled to the island by the king and ordered to clear the forests to supply timber to the mainland. Despite this some areas of primary and secondary forest still remain, and are confined to valleys, ravines and gullys, which have proved too difficult and costly to clear and utilize (McKay 2006). 5

6 The islands flora and fauna as well as Bali s exhibits classic Wallacean transitional diversity with the majority of organisms being associated with the Asian assemblage with a few Sundanese specimens. Indeed, Bali and neighboring Lombok represent the most easterly of many Asian species ranges and the most westerly of the Austronesian species. (Jonsson. Et.al. 2008) The island of Nusa Pendia however is likely to contain far lower species diversity than Bali, due to its small size and few areas of primary habitat. Objectives Project overview To compile a preliminary database of the islands habitat types with reference to the presence of herpetofauna species. With which the integration of future biodiversity and species abundance surveys may provide useful information to further scientific research and conservation projects on Nusa Penida. Applications Once the information from this project has been collected and catalogued it may be used to further a number of scientific research and conservation activities. - Offers information on the islands hereptofauna and habitat types - Provides repeatable study sites for future species diversity research. The collaboration of which can be used to implement a biodiversity monitoring program - Presents an indicator species inventory which can be applied to the foundations reforestation scheme as a measure of colonization success. - Offers a information on habitat types which may be suitable for the foundations rehabilitation and release program. 6

7 Methodology Habitat assessment Before any herpetofauna studies can be implemented the priority will be the assigning of study areas and habitat assessment of these areas. For the purpose of the study 17 sites have been assigned based on distribution throughout Nusa Penida and accessibility. Ideally, to provide a more accurate overview of the entire island areas would be assigned with equal spacing and cover a set area (Sunderland 2006). However due to accessibility issues and time constraints only areas within reasonable distance from roads and paths have been chosen. Basic habitat assessments will be carried out throughout these sites to provide a habitat type database and for the purpose of repeatability, a GPS device will be used to record the co- ordinates and elevation of each study site. The assessment of habitats will be based on- Vegetation types/diversity As literature concerning vegetation identification is limited on the island, the majority of specimens will merely be identified to groups, ie ferns, deciduous trees etc as to provide an example of the major vegetation groups present. Once The habitats have been assessed they can be assigned into board groups outlining the islands environments. Ideally, vegetation would be identified down to species and specimens measured via random sampling quadrats (Sunderland 2006), however with limited time and resources this study will seek to outline habitats for further analysis. Anthropogenic disturbance To gain an understanding of human influence on the assigned areas, disturbance in the form of human habitation, agricultural activity and other activities will be 7

8 measured observationally in terms of distance from the study area and intensity within Soil quality As no equipment is available for soil testing, observational information will be made on the soils quality, depth and content. Herpetofauna diversity survey For the purpose of a reptile and amphibian presence census, several methods were considered for providing optimum results within the study period, sight transect surveys, pitfall and funnel trapping and drift netting. Although both the latter provide high detect ability for small ground dwelling organisms they are completely ineffective at sampling larger specimens or arboreal species (Melbourne 1999). These methods also raise various issues, for example pitfall traps and drift nets require substantial environmental disturbance. This fact is not only impractical in areas with poor soil and dense vegetation, but also highly disturbs agricultural land. This, coupled with the labor intensive nature of these methods indicates that the best method for detection in this particular case is standard sight transects (day/night). This method allows for the detection of arboreal and large terrestrial species, it also has minimal environmental impact with the exception of the presence of researchers. (Sunderland 2006) As such 3 sight transects (morning/afternoon/night) will be carried out on each of the 17 study areas. Transects will ideally be walked for up to two hours with sighting effort being backed by extensive micro- habitats searches. Due to the nature of these methods, no equipment, save the use of maps and GPS devices has been used. 8

9 This method of surveying is not however without its bias. Not only does detect ability vary between groups, species and individuals, but also ability and experience of the researcher. Indeed, many of the smaller Eutropis and other skink specimens are superficially similar, and correct identification may be impossible if one sees only a glimpse of the specimen as it flees (McKay 2006). As such, not only must care be taken in identification, but if the species cannot be identified from the sighting and is not in hand then it must be disregarded and a brief description given. This method, although most certainly not fully conclusive, will provide an outline of the habitat types throughout the island as well as the variety of herpetofauna present. It cannot however be used to make assumptions concerning population dynamics and abundance of the islands reptile and amphibians. If one wishes to implement a study such as this however, these results will provide baseline information on suitable study sites and highlight species, which may provide optimum results. Another major issue, which must be discussed, is the possibility of contact with venomous snakes. Three venomous snakes are known to inhabit Bali, Naja sputatrix, Ophiophagus Hannah and Cryptelytrops albolabris. Another concern is the venom spitting characteristics of Naja sputatrix (McKay 2006). As such it is imperative that a safe distance (4 meters minimum) be kept from these organisms. It should also be noted that a safe distance be kept from any snake which cannot be identified as a non- venomous species. Results The following are the results and observations from the implementation of the above methods concerning habitats types and herpetofauna diversity. Habitat assessment 9

10 Throughout the island 6 major habitat types were identified: Scrubland, savannah, plantation, tropical monsoon forest, tropical rainforest and wetland. It should be noted that the majority of study sites featured two habitat types. For the habitat assessment of the 17 study areas see appendices. Table 1- Habitat types found throughout Nusa penida with relating assessment criteria. Habitat type Vegetation Vegetatio n diversity Anthropogenic disturbance Scrub Acacias, palms, grasses Moderate Moderate Soil quality Low - moderate Wetland Predominately aquatic vegetation,lillies, Mangrove trees, palms High Low High Plantation Palms Low High Low Tropical dry forest Tropical rain forest Savanna h Deciduous/Evergreen trees, acacias, vines, ferns Predominantly evergreen trees, deciduous trees, ferns, vines, palms, acacias Predominantly grasses, acacias, palms High Low High Very high Low Very high Low High Low Herpetofauna diversity surveys During the course of the sight transects throughout the 17 study areas 21 reptile species and 3 amphibian species were found (see table 2 ). Although in many cases more than one individual of a species was seen they have not been recorded as the aim of this study is simply to confirm presence, not attempt to make deductions on population dynamics and abundance. Records of James McKays survey can be found in appendices. Table 2- Presence and distribution information for herpetofauna species recorded on Nusa Penida 10

11 Location Habitat type Species Penangkidan Penida Sebunibus Toyapakeh Ped Pilah Butumalapan Karangsari Sewana Scrub Wetland Tropical dry forest/scrub Plantation Plantation/Scrub Plantation/Tropical dry forest Plantation Tropical dry forest Scrub /Plantation 11 Eutropis multifasciata Varanas Salvator bivittatus Crytodactylus fumosus Hemidactylus frenatus Duttaphrynus melanostictus Varanus salvator bivittatus bivittatus Crytodactylus fumosus Duttaphrynus melanostictus Fejervarya cancrivora Ahaetulla prasina Eutropis multifasciata Dendrelaphis pictus Naja sputatrix Polypedates leucomystax Crytodactylus fumosus Duttaphrynus melanostictus Pytas korros Crytodactylus fumosus Hemidactylus platyurus Eutropis multifasciata Dendrelaphis pictus Coelognathus radiatus Eutropis rugifera Hemidactylus platyurus Ramphotyphlops braminus Eutropis multifasciata Rhabdophis chrysargos Crytodactylus fumosus Ramphotyphlops braminus Eutropis rugifera Hemidactylus frenatus Dibamus taylori Eutropis multifasciata Dendrelaphis pictus Crytodactylus fumosus Boiga multomaculata Lycodon subcintus Lycodon aculus capucinus Ramphotyphlops braminus Eutropis multifasciata

12 Crytodactylus fumosus Hemidactylus frenatus Pejukutan Tropical dry forest Rampholyphlops braminus Eutropis multifasciata Lygosoma bowringii Cryptelytrops albolabris Crytodactylus fumous Lycodon subcinctus Pareas carinatus Tanglad Savannah Eutropis multifasciata Sukartaji Scrub/Plantation Eutropis multifasciata Dendrelaphis pictus Lygosoma bowringii Crytodactylus fumous Debuloh Scrub/Tropical dry forest Varanus salvator bivittatus bivittatus Naja sputatrix Eutropis rugifera Eutropis multifasciata Crytodactylus fumous Cryptelytrops albolabris Tembling Tropical rain forest Polypedates leucomystax Varanus salvator bivittatus Eutropis multifasciata Dibamus taylori Dendrelaphis pictus Duttaphrynus melanostictus Crytodactylus fumous Lycodon aculus capucinus Psammodynastes pulverulentus Mundi Tropical dry forest Eutropis multifasciata Varanus salvator bivittatus bivittatus Lygosoma bowringi Lycodon aculus capucinus Crytodactylus fumous Duttaphrynus melanostictus Varanus salvator bivittatus Pulagan bivittatus Plantation/Tropical dry Eutropis multifasciata forest Crytodactylus fumous Soyo Savannah - 12

13 Discussion With the above habitat assessment, herpetofauna surveys, general observations and secondary source information collected during the course of the study several assumptions can be made concerning the habitat and reptile and amphibian diversity of Nusa Penida. It should be noted however, that the results and conclusions presented here are based on a fairly small amount of data collected over a short period of time, and should serve only to provide an overview of the islands habitats and herpetofauna. The timescale and spectrum of the data are insufficient as to provide accurate representations about the abundance and population dynamics of the islands reptile and amphibians or extensive information concerning its habitats. This article seeks to merely outline herpetofauna species present, provide a preliminary examination of the islands biodiversity and discuss and suggest further research activities. Habitat assessment Firstly it is fairly evident from the habitat assessment and general observations made over the course of the study that the majority of areas on Nusa Penida are sufficiently altered as a result of past and present anthropogenic disturbance. The majority of habitats appear to be of secondary growth with only few areas of primary vegetation. Despite this, Habitats found and assessed are as follows. Savannah This was the most prevalent habitat type throughout the island, being characterized by large quantities of grasses with few other vegetation types and trees above 3 meters almost non- existent with exception of some acacias and bosurrus palms. Soil quality appeared to be poor, with little decaying organic matter and very low water content. Despite poor vegetation diversity and soil 13

14 content active anthropogenic disturbance is comparatively low, indicating possible past incidences for poor habitat. This correlates with the history of deforestation on the island. Plantation The second most prevalent habitat on Nusa Penida, these were characterized by active agricultural activity with crop species ranging from banana s, palms, cassavas, corn and chilies and most often being present in monocultures with heavy anthropogenic disturbance. Vegetation types were reduced to crops with few naturally occurring species. Soil quality was varied between sights from low to moderate with little decaying organic matter and water. It should be noted that many of the sites less intensively farmed areas had thick layers of leave litter which must have led to the variance in soil quality. However slash and burning is the norm in terms of agricultural practice, and is most likely the cause of the lower end of the scale of plantation soil quality. However, a number of these regions were bordered by areas of significantly higher biodiversity (scrub land, monsoon forest) and as such a number of them exhibited higher herpetofauna diversity due to a buffer zone affect of these surrounding areas. Scrubland Scrubland covered large areas of Nusa Penida, appearing to buffer between other habitat types. This habitat was characterized by moderate to high vegetation diversity being mostly acacias, shrubs and small deciduous trees. Soil quality appears to be moderate, with a fair amount of decaying organic matter. It was however fairly poor in terms of water content. These areas often had little to moderate anthropogenic activity often in the form of human habitation and some grazing animals. 14

15 Tropical monsoon forest This was the most prevalent forest habitat on Nusa Penida and appears to be present in many of the valleys, rifts and man made gullies around the island in small isolated areas. The majority of tree species were deciduous with some intermittent evergreens with thick ground vegetation of ferns and shrubs. Vegetation was most often dense and resulted in a thick layer of leaf litter. Soil quality was fairly high, with soil showing sufficient decaying organic matter but still showed only moderate water content. Anthropogenic disturbance was negligible and as a result, biodiversity in these areas appeared to be fairly high. Tropical rain forest This region housed by far the most diverse vegetation on Nusa penida with a myriad of evergreen/deciduous species as well as a host of tropical trees, shrubs, ferns and epiphytes. Soil quality was also excellent with deep layers of decaying organic matter and high water content. Although the most biodiverse region it was also one of the least prevalent with only one large undisturbed region at Tembling. Anthropogenic disturbance was also negligible Wetland A high diversity of aquatic plants and water tolerant species dominated this area which was recorded at only one location, Penida. Anthropogenic presence in the area was fairly high, as the wetland is situated on a fresh water spring, however the influence on the habitat and vegetation was negligible and as such was not recorded. Conclusion Firstly it is fairly obvious that islands vegetation is sufficiently depleted by comparison to mainland Bali, with the only truly biodiverse tropical habitats being confined to the forested valleys present throughout the island. 15

16 This apparent lack of forest is attributed to felling activity initiated by convicts exiled to the island by the king of Bali 400 years ago. It is after this time that the island most likely adopted its arid, scrub/savannah like habitat, with healthy forest regrowth severely hindered by further felling, agricultural activity and the islanders standard slash and burn farming practices (Giambelli1999). This has resulted in the fragmentation of the islands forests, with these remaining areas serving as biodiversity islands for Nusa Penidas flora and fauna. It should be noted that these remaining areas of forest housed by far the highest number of plant species, and as shown form the herpetofauna surveys contained the majority of the islands reptile and amphibian diversity, as such it is likely that they house the majority of the islands other species (birds, mammals invertebrates). Therefore it is highly recommended that future studies of biodiversity be based at these sites, in particular Karangsari, Tembling, Pejukutan and Mundi. Not only do these areas appear to be the most biodiverse but their comparatively small size should make more thorough studies of diversity and population dynamics sufficiently easier. As for the habitat assessments presented here, these should also only be used as a means of identifying and distinguishing between the various habitat types of Nusa Penida. It is highly recommended by this researcher that more in depth habitat analysis be carried out over the entire island as to provide a more in depth knowledge of these areas. This in collaboration with GPS coordinates and ArcView GIS software could provide an island wide habitat database which would provide details of the range and size of Nusa Penidas habitat types. Further integration with biodiversity surveys could also provide an excellent means of confirming areas of biodiversity. Also if yearly updates were made to the database, deductions could be made concerning habitat loss/gain, use by key species and population dynamics of certain species. (Sunderland 2006) 16

17 Herpetofauna diversity surveys The reptile and amphibian surveys and general observations suggest that the forested areas contained higher herpetofauna species diversity than any other habitat on Nusa penida. The wetland and some scrubland sights did exhibit similar, if slightly lower levels of biodiversity however the majority of scrubland habitat contained sufficiently fewer species. The plantation and savannah habitats appeared to show drastically lower species diversity with the latter habitat yielding incredibly poor results. In fact the surveys of the two savannah study areas (Tanglad and Soyo) only one Eutropis multifasciata specimen was found. Amphibians As for the presence and distribution of Nusa Penidas herpetofauna the immediately obvious issues is the minimal amphibian presence on the island. Of the 14 amphibian species known to occur on mainland Bali only 3 were found throughout the course of the survey Duttaphrynus melanostictus, Polypedates leucomystax and Fejervarya cancrivora, with another species, Kaloula baleata being recorded during James McKays study (see appendices). Of these species Duttaphrynus melanostictus was by far the most prevalent, not only being detected within the study areas but also observed throughout the island between sites. Of the other amphibians Polypedates leucomystax was only found at two sites with Fejervarya cancrivora only being recorded in the wetlands of the Penida study site. As one might expect, the most likely cause for this reduced amphibian presence is water quantity. As previously mentioned, Penida was the only wetland habitat found on Nusa Penida, with the only other bodies of water being sufficiently smaller and of lesser quality. The island also receives significantly lower rainfall than mainland Bali, this coupled with the poor soil and Nusa Penidas coral island origins results in little to no water 17

18 holding ability, with streams and rivers only running for a short period after heavy rainfall (McTaggart 1989). As such, the presence of so few amphibian species is to be expected of this island. An interesting aspect however is that amphibians were only detected in the northern and western areas, indeed, even Duttaphrynus melanostictus was not detected in the islands southern and eastern regions. As such it is highly likely that the water holding quality and possibly rainfall on the northern and western areas is sufficiently higher than the rest of the island. Reptiles As for the reptile species found during the course of the study, all were squamates with 9 lizard and 13 snake species recorded throughout the island with a further 2 lizard species and one snake species being recorded by James McKay. Although many of the species recorded were in some numbers it should be noted that the number of species appears to be significantly lower than those recorded on mainland Bali. It should also be noted that no freshwater turtles were found during the course of the study. However this was to be expected due to the low standing water content of Nusa Penida. Although the survey was carried out over a short time period and covered a comparatively small area, and as such can not absolutely rule out species absence. However the lack of suitable habitat coupled with the lack of reported sightings from locals means that the presence of fresh water turtles on the island is highly unlikely. Lizards With the exception of Varanus salvator bivittatus, all the Lacertilla species on Nusa Penida were small insectivores, with 4 Gekkonidae, 3 Scincidae species and Dibamus taylori being the only species found within the Dibamidae family. During the course of the study, the three most widespread and abundant organisms found were Gecko gecko, Cyrtodactylus fumosus and Eutropis multifasciata which all inhabited a widerange of habitats throughout the island. 18

19 All of these species adopted significantly different ecological strategies and were observed to be active at different times and as such were found within the same area and often found in sufficiently higher numbers than other organisms at the study sites. Cyrtodactylus fumosus appeared to be the most abundant of these, possibly due to its highly active terrestrial lifestyle, indeed, during night surveys they were fairly easy to locate due to their fast paced rustling through the leaf litter. and Eutropis multifasciata were the largest of the insectivores found on the island, with Eutropis multifasciata being highly diurnally active and due to its size, fairly easy to spot. This coupled with the tokays distinctive tok- ayy vocal display shows that the reason that these species in particular may have been recorded in higher numbers than others is purely due to their high detectability (Tang et.al. 2001). The other Scincidae found were Eutropis rugifera and Lygosoma Bowringii with Hemidactylus frenatus and Hemidactylus platyurus compromising the remaining Gekkonidae. Hemidactylus frenatus and Hemidactylus platyurus were found predominately around human habitation, usually hunting invertebrates around artificial lights at night (Rich et.al. 2006). The only reason these species are likely to have been recorded to a lesser extent during the study is because human habitations were often avoided for study sites. As such, it is highly likely that these species, as well as the Tokay gecko are in fact the most widespread of the Nusa Penidan Lacertids. As for Lygosoma Bowringii and Eutropis rugifera these were found within deep leaf litter at various study sites throughout the island. Despite the comparatively fewer sightings compared to Eutropis multifasciata it is highly likely that they inhabit the same areas (McKay 2006). During the course of the study, many small skinks fled before they could be correctly identified resulting in limited confirmed sightings. Despite this, the presence of these species was evidence 19

20 enough that their leaf litter habitat was providing a rich microhabitat for invertebrates and small vertebrates, as more often than not a large number of individuals were found at the same sights within close proximity. Dibamus taylori was found at only two sites, both were found under rocks and logs in densely forested areas with deep leaf litter. Dibamus taylori presents an interesting case as it was the only specimen found during the study which is not a part of the south east Asian assemblage of organisms. In fact Dibamus taylori and the other Dibamids are found throughout the lesser Sundas inhabiting the seasonally dryer areas east of Bali (Hallerman 1998). Therefore it is highly likely that Nusa Penidas Dibamid population is at the westernmost point of their distribution. Despite this and their comparative isolation, Nusa Penidas individuals retain the anatomical characteristics of other Dibamus taylori populations throughout their range, possibly suggesting a recent dispersal to Nusa penida from the Lesser Sundas. Snakes The most diverse of the herpetofauna species found on Nusa penida are serpentines with 13 species within 4 families, Typhlopidae, Colubridae, Elapidae and Crotalidae. During James McKays surveys several sightings of Broghammerus reticulatus (Family: Pythonidae) were also made (see appendices). The species found showed a range of size, activity and ecology, with the majority being small to medium sized terrestrial/arboreal snakes known to prey on small vertebrates, most likely lizards. Despite this high diversity, only a few species were recorded regularly, with the majority of observations made being of single specimens. As is expected, snakes were found in sufficiently lower numbers than lizards on the island and in far fewer habitats, with the majority of species found in the monsoon/rain forest regions of the island. It should also be noted that during the course of the study only 3 species measuring over a meter were found. These 20

21 were Najas putatrix, Pyta skorros and a large unidentified Colubrid specimen located at Tembling. Also during the course of James Mckays research, only two Broghammerus reticulatus speciemens and the skins of two Naja sputatrix were recorded. This apparent lack of large snakes may possibly be explained by the islands low mammalian populations. Although several species have been unofficially recorded on Nusa Penida only a few were encountered during the course of the study, possibly suggesting reduced population sizes. However, due to the lack of baseline data concerning mammalian populations and the abundance of large snake species, this theory can only be speculative. As a result it is highly suggested that further research be carried out on the abundance of these organisms. Concerning the other snakes found on Nusa Penida the most abundant and widespread appeared to be Dendrelaphis pictus, Ramphotyphlops braminus, Lycodon aulicus capucinus and Lycodon subcinctus respectively. With the exception of Ramphotyphlops braminus all are highly active (which no doubt increases their detect ability) small vertebrate predators. Both Lycodon species are nocturnal, and judging by the difference in size, most likely hunt different prey items, preventing inter species competition. Dendrelaphis pictus although similar in ecology, is a diurnal species, and the most arboreal, therefore adopting a similar yet non overlapping ecological niche. Ramphotyphlops braminus is the most ecologically distinct of Nusa penidas snake species. Its ecology and morphology closely resembles that of Dibamus taylori as opposed to any of the other snake species. This partially subterranean nocturnal snake spends the majority of its time burrowing through leaf litter in search of suitable invertebrate prey items and as such is rarely encountered. In fact all Ramphotyphlops braminus specimens recorded were found under rocks or logs. This micro habitat utilization coupled with their parthenogenic reproductive system has not only allowed this species to utilize the majority of habitats on Nusa Penida, but also has allowed its colonization of suitable habitats throughout the world (Kamosawa et.al 1996). 21

22 Conclusion During the course of the study and with information obtained from secondary sources it is apparent that Nusa Penida has sufficiently lower Herpetofauna diversity than mainland Bali. The islands amphibian diversity in particular is drastically lower, which is most likely the result of not only the wide sea crossing but also the islands low water content and annual rainfall. Reptile species present on the island exhibit a range of lifestyles and ecotypes with the majority of species being found in the biodiverse yet restricted forest regions. There also appears to be sufficient prey items to accommodate a large number of snake species, which suggests a fairly healthy population of prey species (small vertebrates). It should be noted that due to time constraints and other restrictions it is likely that a number of species have not been recorded, indeed, several species recorded during James McKays search effort were not detected during this study, and vice versa. As such it is highly recommended that the study be repeated every few months with particular focus around the rainy season (November- February). This would coincide with the breeding seasons of many of the islands reptiles and amphibians, a time when activity and abundance are at there highest. Indeed, many of the local villagers throughout the island unanimously agreed that the vast majority of herpetofauna sightings, particularly snakes occurred throughout January, the middle of the rainy season. Acknowledgments Firstly many thanks must go to Agus Pradana Putra my research assistant who provided invaluable assistance throughout the project. Also to James McKay, 22

23 whose knowledge and expertise proved incredibly useful. Above all most thanks to the FNPF staff who have not only made this research possible but have also provided constant support and advice throughout the project References Giambelli.R (1999) Working the land: Babad as forest clearing and analogy between land and human fertility in Nusa Penida (Bali) Bijdragen tot de Taal-, Land- en VolkenkundeVol 155 (4) Hallermann.J (1998) The ethmoidal region of Dibamus taylori (Squamata: Dibamidae), with a phylogenetic hypothesis on dibamid relationships within Squamata. Zoological Journal of the Linnean Society. Vol.122 (3) How. R.A, Kitchener. D.J (2003) Biogeography of Indonesian snakes. Journal of biogeography.vol 24 (6) Jonsson. K.A, Irestedt. M, Fuchs. J, Ericson. P.G.P, Christidis. L, Bowie. R.C.K, Norman. J.A, Pasquet.E, Fjeldsa.J (2008) Explosive avian radiations and multi- directional dispersal across Wallacea: evidence from the Campephagidae and other Crown Corvida (Aves) Molecular Phylogenetics and Evolution. Vol 47, Kamosawa. M, Ota. H (1996) Reproductive biology of the brahminy blind snake (Ramphoyphlops braminus) from the Ryukyu archipelago, Japan. Journal of herpetology. Vol. 30 (1) 9-14 McKay.J (2006) A field guide to the reptiles and amphibians of Bali. Kreiger publishing company, USA. 23

24 McTaggart. W.D (1989) Hydrologic management in Bali.Singapore journal of tropical geography.vol: 9 (2) Melbourne. B.A (1999) Bias in the effect of habitat structure on pitfall traps: An experimental evaluation.australian journal of ecology.vol 24, Noss.R (1990) Indicators for monitoring biodiversity: a hierarchical approach. Conservation biology. Vol.4 (4) Rich. C, Longcore. T (2006) Ecological consequences of artificial night lighting. Island press, USA. Sunderland.W.J (2006) Ecological census techniques: A handbook. 2 nd Edition, Cambridge University Press. United Kingdom Tang. Y, Zhuang. L, Wang.Z (2001) Advertisement Calls and Their Relation to Reproductive Cycles in Gekko gecko (Reptilia, Lacertilia). Copeia. Vol (1)

25 Appendices Table 3 Habitat assessments of the 17 study sites throughout Nusa Penida Location Batumulapa n Altitude (meter) dpl 6 GPS Point Habitat Type Vegetation S E Vegetatio n diversity Anthropogeni c disturbance Soil quality Plantation Palms Low High Low Karangsari 35 S E Tropical Dry forest Deciduous/Evergreen trees, acacias, ferns, vines High Low High Sumaya 8 S E Scrub /Plantation Acacias, palms, grasses Moderate Moderate Poor Pejukutan 245 S E Tropical dry forest Deciduous/Evergreen trees, acacias, vines, ferns High Low High Tanglad 442 S E Savannah Predominantly grasses, acacias, palms Low Moderate Low Sukartaji 234 S E Scrub/Plantatio n Acacias, palms, grasses Moderate - High High Moderate Mundi 530 S E Tropical dry forest Deciduous/Evergreen trees, ferns, vines, acacias High Low High Pangalan 288 Soyo 444 Penangkidan 203 Penida 19 Sebunibus 147 Toya Pakeh 13 S E S E S E S E S E S E Plantation/Tropi cal dry forest Savannah Scrub Wetland Tropical dry forest/scrub Deciduous trees, palms, acacias Predominantly grasses, acacias, palms Acacias, palms, grasses Predominately aquatic vegetation,lillies, Mangrove trees, palms Deciduous trees, vines, ferns, palms, acacias Moderate- High Moderate Moderate Low High Low Moderate Moderate Low - moderate High Low High Moderate - High Moderate Moderate Plantation Palms Low High Low 25

26 Ped 7 S E Plantation/Scru b Acacias, palms Moderate Moderate Moderate Pilah 182 S E Plantation/Tropi cal dry forest Deciduous trees, palms, acacias Moderate Moderate Moderate Sebuluh 195 Tembeling 259 S E S E Scrub/Tropical dry forest Tropical rain forest Deciduous/Evergreen trees, ferns, vines, acacias Predominantly evergreen trees, deciduous trees, ferns, vines, palms, acacias High Low High High Low Very high Table 4- Copy of James L McKays records on herpetofauna searches on Nusa Penida Date Location Species Sampalan Lycodon aulicus capuchinus Sampalan Gekko gecko Sampalan Hemidactylus frenatus Sampalan Hemidactylus platyurus Sampalan Cyrtodactylus fumosus Broghammerus reticulatus Sampalan (skin) Goa Karangsari Rhabdophis chrysargos Goa Karangsari Broghammerus reticulatus Goa Karangsari Cyrtodactylus fumosus Goa Karangsari Gekko gecko Desa Ponjok(?) Eutropis multifasciata Desa Ponjok(?) Gehyra mutilata Desa Ponjok(?) Dendrelaphis pictus Desa Karang Dibamus cf taylori Toyapakeh Lygosoma bowringii Toyapakeh Broghammerus reticulatus Toyapakeh Cyrtodactylus fumosus Toyapakeh Lycodon aulicus capuchinus Toyapakeh Duttaphrynus melanostictus Toyapakeh Gekko gecko 26

27 Jungkutbatu Kaloula baleata Jungkutbatu Lycodon aulicus capuchinus Jungkutbatu Lygosoma bowringii Jungkutbatu Cryptoblepharus renschi Jungkutbatu Gekko gecko Jungkutbatu Gehyra mutilata Jungkutbatu Hemidactylus frenatus Jungkutbatu Cyrtodactylus fumosus Sampalan Hemidactylus frenatus Sampalan Hemidactylus platyurus Sampalan Gekko gecko Ped Naja sputatrix (skin) Ped Varanus salvator bivittatus bivittatus Ped Hemidactylus frenatus Ped Gekko gecko Ped Duttaphrynus melanostictus Tembeling Eutropis multifasciata Tembeling Dendrelaphis pictus Ped Ahaetulla prasina Ped Lycodon aulicus capuchinus Ped Gehyra mutilata Ped Varanus salvator bivittatus bivittatus Ped Gekko gecko Ped Hemidactylus platyurus 27

28 Ped Gehyra mutilata Ped Duttaphrynus melanostictus Table 5 A comprehensive list of herpetofauna species found on Nusa Penida. Compiled from field surveys and secondary research Amphibia Anura: Bufonidae: Duttaphrynus melanostictus Microhylidae: Kaloula baleata Ranidae: Fejervarya cancrivora Rhacophoridae: Polypedates leucomystax Reptilia Squamata: Lacertilla Dibamidae: Dibamus taylori Gekkonidae: Hemidactylus platyurus Crytodactylus fumous Gekko gecko Gehyra mutilata Hemidactylus frenatus Scincidae: Cryptoblepharus renschi Eutropis multifasciata Eutropis rugifera Lygosoma bowringii Varanidae: 28

29 Varanus salvator bivittatus Squamata: Serpentes Colubridae: Ahaetulla prasina Boiga multomaculata Coelognathus radiatus Dendrelaphis pictus Lycodon aulicus capucinus Lycodon subcinctus Pareas carinatus Psammodynastes pulverulentus Pytas korros Rhabdophis chrysargos Crotalidae: Cryptelytrops albolabris Elapidae: Naja sputatrix Pythonidae: Broghammerus reticulatus Typhlopidae: Ramphotyphlops braminus 29