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Corresponding author: Amirrudin B. Ahmad ( amirrudin@umt.edu.my ) Academic editor: Anthony Herrel
© 2020 Muhamad Fatihah-Syafiq, Baizul Hafsyam Badli-Sham, Muhammad Fahmi-Ahmad, Mohamad Aqmal-Naser, Syed Ahmad Rizal, Mohd Shahrizan Azrul Azmi, Larry L. Grismer, Amirrudin B. Ahmad.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
Fatihah-Syafiq M, Badli-Sham BH, Fahmi-Ahmad M, Aqmal-Naser M, Rizal SA, Azmi MSA, Grismer LL, Ahmad AB (2020) Checklist of herpetofauna in the severely degraded ecosystem of Bidong Island, Peninsular Malaysia, South China Sea. ZooKeys 985: 143-162. https://doi.org/10.3897/zookeys.985.54737
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A herpetofaunal inventory was conducted on Bidong Island, Terengganu, Peninsular Malaysia. It incorporates data from a recent herpetological survey conducted from 1 to 3 April 2019 with reptile records from previous publications. Specimens were collected with drift-fenced pitfall traps and taxa were recorded with visual encounter surveys (VES). In total, 18 species of reptiles and amphibians were recorded, including three species of frogs, 12 species of lizards, and three species of snakes. Six species from the present survey are new records for the island.
amphibian, Bidong Island, herpetological survey, Peninsular Malaysia, reptile, South China Sea
The South China Sea has environmentally diverse groups of islands that have engaged researchers’ attention for the past two decades (
The Bidong Archipelago comprises six islands with Bidong Island (Fig.
The fauna of Bidong Island was apparently first studied by
In this article, we report the baseline data on a collection of amphibians and terrestrial reptiles acquired during a recent survey on the western side of Bidong Island in early April 2019. This report incorporates the findings of
Bidong Island, the largest island of the Bidong Archipelago, has a land area of about one square kilometre and is 321 m above sea level at its highest point. The island was used for housing Vietnamese refugees from 1975 to 1991. The settlement area (Fig.
Field surveys were conducted at the western part of Bidong Island, Terengganu, Malaysia from 1 to 3 April 2019. Study areas included chalets and research facilities, hilly areas, accessible forest trails, coastal vegetation as well as stagnant ponds near Pantai Pasir Cina (5°37'16"N, 103°3'28"E), Pantai Pasir Pengkalan (5°36'53"N, 103°3'32"E) and Pantai Pasir Tenggara (5°36'43"N, 103°3'36"E). Specimens were inventoried using the following approaches: Visual Encounter Survey (VES) and drift-fenced pitfall traps. VES is an active collecting method used to sample for species richness and abundance along the survey area by an observer under a time limit condition (
The VES method involved active searching and was conducted during the day (10 am to 4 pm) and at night (8 pm to 11 pm) to record both diurnal and nocturnal species. Animals were caught by hand or with snake tongs. Identification of amphibians follows
List of terrestrial amphibians and reptiles recorded from Bidong Island, Terengganu in this study and from
Family | Species |
|
This study | IUCN Status |
---|---|---|---|---|
Amphibians | ||||
Microhylidae | Kaloula pulchra | – | + | LC |
Microhyla heymonsi | – | + | LC | |
Rhacophoridae | Polypedates leucomystax | – | + | LC |
Reptilians | ||||
Agamidae | Bronchocela cristatella | + | + | NE |
Scincidae | Dasia olivacea | + | + | LC |
Eutropis multifasciata | + | + | LC | |
Gekkonidae | Cnemaspis bidongensis | + | + | LC |
Gekko cicakterbang | + | + | NE | |
Gekko gecko | + | + | LC | |
Gekko monarchus | + | – | NE | |
Hemidactylus frenatus | + | + | LC | |
Hemidactylus garnotii | + | – | NE | |
Hemidactylus platyurus | + | + | NE | |
Lepidodactylus lugubris | + | + | NE | |
Varanidae | Varanus salvator | + | + | LC |
Colubridae | Lycodon capucinus | – | + | LC |
Pythonidae | Malayopython reticulatus | – | + | NE |
Typhlopidae | Indotyphlops braminus | – | + | NE |
Total no. of species/study | 12 | 16 | ||
Total no. of species | 18 |
In this checklist, taxonomic categories are alphabetically arranged and information for each species is presented in the following format: family name, species name, English name, notes and known distribution of the species in the offshore islands of Terengganu.
Table
Order Anura
Suborder Neobatrachia
The banded bullfrog is fossorial but also shelters in burrows, tree holes and beneath surface objects. On 1 April 2019, one specimen was collected in a small tree cavity about 1.5 m above ground near MNRS at night.
Many individuals were observed on the ground near puddles in grassy areas. Several males can be heard calling from the puddles. On 1 April 2019, a single specimen was collected from a stagnant puddle near MNRS at night. This specimen agrees with the morphology diagnosis by
This species was commonly observed on the hiking trail about 10 m above sea level. Individuals were located at night perching on leaves and branches of low to medium level vegetation. One was collected on a leaf 1 m above the ground at night on 2 April 2019. It matches the diagnosis of the species by
Order Squamata
Suborder Sauria
Family Agamidae
This striking green-coloured and diurnal lizard is active during the day and can be commonly found in open areas on bushes and trees from 1 to 3 m above the ground. On 2 April 2019, eight individuals were observed and a specimen was collected from Pantai Pasir Pengkalan. Two large individuals were seen climbing up to 3 m high on a tree near Pantai Pasir Tenggara . All examples on Bidong Island match the diagnosis of this species by
Cnemaspis bidongensis is apparently endemic to Bidong Island where it seemed to be common. It inhabits forest in the interior of the island where it was found on rocks, twigs and tree trunks. About five individuals were observed on 1 April 2019 in the forest near MNRS. The species was described in 2014 by Grismer et al.
This gecko was occasionally observed on man-made structures in MNRS. It is nocturnal and apparently has the capability to glide from one tree to another. Until 2019, this species was thought to be conspecific with Ptychozoon lionotum (see
This large species of gecko was common on Bidong Island, especially at the MNRS area. Individuals observed match the diagnosis of the species by
This species was not sighted in this study but was reported by
Gekko monarchus is known from Perhentian Besar, Redang and Tenggol islands (
Hemidactylus frenatus is a widespread species that seems to have a preference for human settlements and disturbed forest on Bidong Island. Individuals observed match the diagnosis of this species in
This gekkonid is found on all of Terengganu’s offshore islands except Susu Dara Kecil Island (
Although reported to occur on Bidong Island by
This species has been observed in Kuala Aring, Kelantan (
This species was observed living in syntopy with Hemidactylus frenatus in human settlements near MNRS. Individuals seen match the diagnosis of this species in
Off the Terengganu coast, Perhentian Besar Island seems to be the only other island where Hemidactylus platyurus has been recorded (
On Bidong Island, one individual was found near Pantai Pasir Pengkalan. Its appearance matches the diagnosis of the species in
Dasia olivacea is diurnal, arboreal species that can be seen basking head down on tree trunks. About three individuals were observed from 1 to 3 April 2019, and all were about 2 m high on trees. One was seen with a small, unidentified gecko in its mouth on 2 April 2019. The predation of this species on geckos was reported by
This species is also recorded from Perhentian Besar, Perhentian Kecil, Redang and Tenggol islands (
This common skink can be found across almost all habitats, including disturbed forest, open areas, human settlements and primary forest. It was very common at Pantai Pasir Pengkalan with 11 individuals being recorded during the recent survey. Specimens observed match the diagnosis of this species by
Several individuals of this large, diurnal lizard that weres seen frequently on Bidong Island from 1 to 3 April 2019, especially near MNRS, due to the availability of food at the garbage piles. They were observed foraging in the afternoon and evening before dusk. The appearance of those lizards matches the diagnosis of this species in
This species has been recorded on many islands off Terengganu except Susu Dara Kecil, Seringgeh and Tokong Burung Besar islands (
Family Colubridae
This nocturnal snake was common on Bidong Island where individuals were often found beneath logs, rocks and beach debris. Several individuals were observed near MNRS and Pantai Pasir Pengkalan on 1and 2 April 2019. The individuals examined match the diagnosis of the species in
This large and widespread snake can be found in a wide variety of habitats and preys on large animals. A 2 m long individual was spotted at night on 2 April 2019 among grass near Pantai Pasir Pengkalan. It fits the diagnosis of the species in
Also recorded from Perhentian Besar, Susu Dara Besar, Redang and Tenggol islands (
This small fossorial snake resembles an earthworm and seems to occur largely in human settlements. It feeds on the larvae of ants and termites, and is known to be parthenogenic. One specimen was captured on surface debris at night on 2 April 2019 near MNRS. Its morphology matches the diagnosis of the species in
Indotyphlops braminus was recorded by
Human activities are the major cause of an island’s ecosystem degradation around the world (see
It has been almost 30 years since the Vietnamese occupants left Bidong Island and the persistence of the herpetofauna to withstand the human-imposed pressure in the past is remarkable despite the great deterioration of the island’s forest ecosystem. Since then, anthropogenic abandonment and forest succession may help terrestrial herpetofauna to recover (
Many of the species on the island are to some extent human commensals, and some may even have been introduced with human occupation of the island. High densities of species such as Microhyla heymonsi, Kaloula pulchra, Gekko gecko, Varanus salvator, Hemidactylus frenatus and Bronchocela cristatella were also observed in this study. Anthropogenic-adapated species such as G. gecko and H. frenatus could also be accidentally introduced by humans during the arrival of the refugees on the island, which also may influence the abundance of these species on this island. Hypothetically, the abundance of these species may result from the availability of microhabitat as refugia, lack of predators, availability of food resources, human introduction and density compensation due to missing interspecific competitors in the island (
Generally, many species that occur on this island are ubiquitous species; hence these do not require a specialized microhabitat. Reptiles in particular, have a suit of biological traits that may help them to subsist on this island such as efficiency in energy expenditure, flexibility in growth development and ability to shift diet spatially and/or temporally (see
The results of this inventory are not conclusive, as the studies done only covered several small sites of the island. Large parts of the island forest are still unexplored, thus the results may not represent the true species richness of the island. The north-eastern part of the island is rugged with steep slopes and sharp outcrops, hence has limited access during the survey. The northern, central and eastern parts of the islands’ forests are still unexplored. These large areas (which encompassed 60% of the island’s landscape) are now covered by mature secondary forest and receive less human disturbance after the recovery of the forest from the past incident. Increased sampling efforts, in terms of sampling areas and sampling time, may result in the discovery of new island records, perhaps even new ground dwelling species with the installation of pitfall traps. Long-term monitoring and ecological studies are needed to realize the true diversity of herpetofauna and improve the conservation of the terrestrial herpetofauna.The herpetofauna of Bidong Island survived the catastrophic ecological event in the past, but the resilience of species to recover after land abandonment and forest succession (true species richness and population density) remains in question. Abandoned habitat from the past and intact forests need to be maintained and undisturbed to promote the persistence of this island’s herpetofauna. This study provides baseline data for ecological monitoring and studies which are crucial to uncover the diversity of this insular herpetofauna and inform conservation authorities and stakeholders about current and future conservation management.
We thank Universiti Malaysia Terengganu, specifically the Centre of Research and Field Service (CRAFS) for the accommodation and supporting staff to facilitate this research at Pulau Bidong Marine Nature Research Station as well as the Faculty of Science and Marine Environment (FSSM) and the Institute of Tropical Biodiversity and Sustainable Development (IBTPL) for the equipment provided to conduct this study and sponsoring this research. We thank the anonymous reviewer for helpful comments.