The Amphibians of Mount Gede Pangrango and Mount Salak, Indonesia
Posted by Miqe on June 14, 2007
By Mirza D. Kusrini, A. Fitri, W. Endarwin and M. Yazid
Although there is good evidence that amphibian declines are a global problem, most reported amphibian declines have occured in developed countries or in countries that have a strong research culture. Almost no declines have been reported in Indonesia. However this may be due to a lack of research and long-term monitoring in this country (Iskandar & Erdelen, 2006).
In 2003, we conducted amphibian surveys in two mountainous areas in West Java province: Mount Gede Pangrango National Park (highest peak 3,400 m above sea level) and Mount Salak (part of Mount Salak-Halimun National Park; with the highest level of 2211 m). Both mountains represent some of the few remaining pristine areas of the heavily populated West Java province. Liem (1971) described 19 species of amphibians in the Cibodas Trail of Mount Gede from 1961 to 1964. Unfortunately, there are no further available reports of Mount Gede amphibians after this time. There are no comprehensive surveys of the amphibian fauna of Mount Salak region either, and only a few reports on amphibian biodiversity in adjacent areas. Surveys by The Indonesian Insitute of Science (LIPI) in 1999-2001 in Mount Halimun region found 27 species of frogs (Mumpuni, 2002).
We conducted Visual Encounter Surveys (Heyer et al., 1994) in several locations inside the national park with different types of habitat encompassing the forest floor, water bodies and surrounding vegetation. The occurrence of a species was determined by finding adults as well as larvae and if possible by male vocalization. Surveys in Mount Gede were conducted from September 2004-February 2005, comprising nine locations ranging from 700-2740 m asl including locations reported by Liem (1971). A second series of monitoring surveys has been underway since November 2006. Surveys in Mount Salak were conducted in 7 locations, ranging from 700-340 m asl from December 2005-June 2006. Each location was visited once, for four days in a row.
In total we found 19 and 21 species from five families (Bufonidae, Megophrydae, Microhylidae, Ranidae and Rhacophoridae) for Mount Gede Pangrango NP and Mount Salak NP respectively. The number of species found in Mount Gede Pangrango NP were less than those found by Liem (1971) and species composition differed. Four species from Liem’s result were not found in the first survey: Fejervarya cancrivora, Bufo bipocartus, Microhyla palmipes and Rana nicobariensis. Instead, we found additional species: Rana hosii, Leptophryne borbonica, and Limnonectes macrodon. During our second year monitoring in Mount Gede Pangrango NP (November 2006-February 2007) we found the missing M. palmipes. A particularly important finding was of a caecilian Ichthyophis hypocyaneus in Bodogol (700 mm asl). This is the first record of a caecilian in Mount Gede Pangrango NP. No mass mortalities were found on either mountain, however, an adult Limnonectes kuhlii was found dead, floating in a small pu!
ddle of water on the side of a walking trail in Chevron Geothermal Concessions in Mount Salak.
With additional data based on the work from Mumpuni (2002), we compiled a list of 26 frog species in the vicinity of Mount Gede Pangrango NP and Mount Halimun- Salak NP area which represent almost two-thirds of the total Java species (Iskandar, 1998). From this list, 12 species were not found in one or two locations. Based on the known biology and distribution of each of these species, we categorized three types of threat. “Red” represents species that are currently under threat, “yellow” represents species that might be vulnerable to threats and “green” represents species of least concern.
Leptophryne cruentata is the only species that is currently under threat (IUCN Red List, Critically Endangered). This small bufonid is currently found in Curug Cibeureum (Mount Gede Pangrango NP). The number found during the first sampling was very low (three individuals). However, during the second sampling we found more individuals including an aggregation of about 15 frogs which were well hidden in a moss-covered rock crevice in a wall of one of the three waterfalls in Cibeureum. Kurniati (2003) found three individuals of L. cruentata in Cikeris (Mount Halimun), which suggest that the current distribution of this frog is not restricted to the Cibeureum area alone.
We put three species of tree frogs (Nyxticalus margaritifer, Philautus vittiger and Philautus pallidipes) and a caecilian Ichthyophis hypocyaneus in the “yellow” category. All three tree frogs are endemic to Java with little or no bio-ecology information available. This entire species is rare, probably because of their cryptic nature (the genus Philautus are very small), although we can- not dismiss the possibility that populations may be in decline.
Seven species were placed in the “green” category (Bufo bipocartus, Rana nicobariensis, Rana erythraea, Fejervarya cancrivora, Occidozyga sumatrana, Microhyla palmipes). Although only found in one or two locations, almost all of these species are found in human settlements and are widely distributed .
There are several potential threats for frogs in both areas. Anthropogenic threats in the form of habitat modification are relatively absent in Mount Gede Pangrango, but more apparent in Mount Salak. Other potential threats are due to human visitation in the national park which include trampling of bottom substrate and more importantly solid waste such as plastics and empty tin cans.
Although chytridiomycosis has not yet been detected in Indonesia, locations in high elevations have suitable environmental conditions favourable to chytrid. For instance the temperature in Gede Pangrango NP and Halimun Salak NP in West Java ranges from from 13.5-28C in the morning to 9-21C at night. The humidity in all locations is high, ranging from 63- 100%. Using environmental variables, Ron (2005) developed a model to identify the geographic ranges of B. dendrobatidis. Although the primary focus of Ron’s research is neotropical, his model also predicted the occurrence of B. dendrobatidis in the montane forests of Java and Sumatra.
Knowledge of the population dynamics, ecology and biology of the amphibians in this report is generally poor. Therefore, there is a need to do more research to ensure conservation of these species, and in particular, for determining the cause of decline of L. cruentata.
We thank our volunteers for this project especially M. Lubis, N. Sholihat, A. Ul-hasanah, S. Kirono, F. Irawan, M. H. Lutfi, and B. Darmawan. Funding for this survey was granted from BP Conservation Programme (Mount Gede Pangrango) and The Wildlife Trust (Mount Salak) for which we are grateful.
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IUCN. (2006) 2006 IUCN Red List of Threatened Species. <www.iucnredlist.org>. (Accessed on the 15th of November 2006).
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Ron, S. R. (2005) Predicting the distribution of the amphibian pathogen Batrachochytrium dendrobatidis in the new world. Biotropica 37: 209-221.