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The Komodo National Park in the Wallacea region is the komodo dragon’s primary habitats. Published report on the herpetofauna of this national park is mostly concentrated in Komodo island. To increase our knowledge of amphibian and reptile communities in Komodo National Park, we conducted a herpetofauna survey in Komodo and Rinca Island and the nearby coastal area to assess diversity and community similarity and developed a complete checklist of the herpetofauna of Komodo National Park. We conducted a Visual Encounter Survey and put glue traps from February-April 2018 at six locations on Komodo Island (Loh Liang, Loh Wau dan Komodo Village) and Rinca Island (Loh Buaya, Loh Baru, and Rinca Village); and three locations on coastal areas of Flores (Labuan Bajo and Cumbi Village) and coastal area of Sumbawa (Sape) adjacent to Komodo National Park. We found seven species of amphibians and 22 species of reptiles and, however, only two species of amphibians and 18 species of reptiles were found in Komodo and Rinca Island. The highest diversity (H’ = 2.14) is in Loh Buaya (Rinca Island), and the highest evenness (E=0.58) is in Loh Baru (Rinca Island). The highest similarity occurs between Komodo Island and Rinca Island (IS = 0.8). Using data from other research, we have compiled a list of four species of amphibians and 39 species of reptiles occurring at three main islands of Komodo National Park: Komodo island, Rinca Island and Padar Island. Keywords: Herpetofauna diversity, Komodo National Park, Lesser Sunda Islands
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Media Konservasi Vol.26 No.3 Desember 2021: 217-230 ISSN: 0215-1677
DOI: 10.29244/medkon.26.3.217-230 E-ISSN: 2502-6313
217
THE AMPHIBIANS AND REPTILES
IN KOMODO NATIONAL PARK AND THE SURROUNDING AREA
UMAR F. KENNEDI 1*), MIRZA D. KUSRINI1), ANI MARDIASTUTI1), AND ACHMAD ARIEFIANDY2)
1) Department of Forest Resources Conservation and Ecotourism, Faculty of Forestry and Environment, IPB
University, Bogor, 16680, Indonesia
2) Komodo Survival Program, Denpasar, 80117, Indonesia
*Email: umarfhadlikennedi@gmail.com
Accepted March 22, 2021 / Approved November 30, 2021
ABSTRACT
The Komodo National Park in the Wallacea region is the komodo dragons primary habitats. Published report on the herpetofauna of this
national park is mostly concentrated in Komodo island. To increase our knowledge of amphibian and reptile communities in Komodo National Park,
we conducted a herpetofauna survey in Komodo and Rinca Island and the nearby coastal area to assess diversity and community similarity and
developed a complete checklist of the herpetofauna of Komodo National Park. We conducted a Visual Encounter Survey and put glue traps from
February-April 2018 at six locations on Komodo Island (Loh Liang, Loh Wau dan Komodo Village) and Rinca Island (Loh Buaya, Loh Baru, and
Rinca Village); and three locations on coastal areas of Flores (Labuan Bajo and Cumbi Village) and coastal area of Sumbawa (Sape) adjacent to
Komodo National Park. We found seven species of amphibians and 22 species of reptiles and, however, only two species of amphibians and 18
species of reptiles were found in Komodo and Rinca Island. The highest diversity (H = 2.14) is in Loh Buaya (Rinca Island), and the highest
evenness (E=0.58) is in Loh Baru (Rinca Island). The highest similarity occurs between Komodo Island and Rinca Island (IS = 0.8). Using data from
other research, we have compiled a list of four species of amphibians and 39 species of reptiles occurring at three main islands of Komodo National
Park: Komodo island, Rinca Island and Padar Island.
Keywords: Herpetofauna diversity, Komodo National Park, Lesser Sunda Islands
INTRODUCTION
Komodo National Park is a conservation area in the
Wallacea region, known as the region with low
biodiversity but rich in endemicity (Monk et al., 1997).
As a conservation area, Komodo National Park primarily
designated to preserve the charismatic and threatened
species, komodo dragon (Varanus komodoensis), and its
habitat. The national park comprises two large islands
(Komodo and Rinca) and three smaller islands (Padar,
Gili Motang, and Nusa Kode) inhabited by Komodo
dragons. These islands are located between Sumbawa
and Flores islands.
Since the national park focus is the conservation of
the komodo dragon, there is a lack of study on the other
species of reptiles or amphibians (see Ardiantiono et al.
2018, Ciofi et al., 1999, Jessop et al. 2018, Purwandana
et al., 2016). During his research on the behavioral
ecology of the komodo dragon (from 1969 to 1973),
Auffenberg collected specimens of amphibians and
reptiles in Komodo Island using accidental sampling. He
reported two amphibians and 28 reptiles, including
marine species in Komodo Island. For more than 30
years afterward, there has been no other report on
amphibian and reptile species of Komodo National Park
until Wahyuni (2012) reported 16 species of reptiles
from 7 families from Padar Island. A few years later, a
booklet on amphibian and reptile of Komodo National
Park was written by Somaweera et al. (2018), which
listed four species of amphibians and 39 species of
reptiles, including marine species. The list was produced
mainly based on accidental sighting and did not specify
the distribution of the species within the islands of
Komodo National Park. The list also did not identify the
most abundant species and the herpetofauna community
of each island.
Labuan Bajo in coastal Flores Island and Sape in
coastal Sumbawa Island are the main entry points for
tourism activity in the Komodo National Park. High
mobility of sea transport between locations is considered
as the pathway for the distribution of invasive species
(Hulme et al., 2008). To increase our knowledge of
amphibian and reptile communities in Komodo National
Park, we conducted a herpetofauna survey in Rinca dan
Komodo Island and the adjacent coastal area to assess the
diversity and the similarity of the herpetofauna of
Komodo National Park with the surrounding coastal area
from the nearby mainland. Using additional information
from Somaweera et al. (2018), Wahyuni (2012), and
Auffenberg (1980), we then developed a complete list of
amphibian and reptile of Komodo National Park.
RESEARCH METHOD
We conducted field surveys in six locations within
two main islands of Komodo National Park and three
locations outside of the national park. The locations
within the national park were Komodo Village, Loh
Liang, Loh Wau (Komodo Island); Rinca Village, Loh
The Amphibians And Reptiles
218
Buaya, Loh Baru (Rinca Island); and locations outside
the national park were Sape (coastal Sumbawa Island),
Labuan Bajo, and Cumbi village (coastal Flores Island)
(Fig 1). The habitat characteristic of each location is
similar, mostly dry, and arid valleys with an elevation
between 2-270 m a.s.l. The freshwater source was
available in Komodo Village, and Loh Wau with stream
flows throughout the year. However, in Loh Liang, there
is no water sources, and the stream only flows during the
rainy season. All locations in Rinca have water all year
round. Labuan Bajo and Cumbi Village (Flores) are also
considered dry; however, they were relatively wetter than
Komodo and Rinca Islands. The Cumbi Village is near
Wae Wuul Nature Reserve, a Komodo dragon habitat
outside the national park (Ariefiandy et al., 2015). Water
sources are plentiful and flow throughout the years in the
area. Similarly, Sape in the eastern part of Sumbawa is
also wetter, with water that flows all year round. Sape
and Labuan Bajo are the main entry points to enter
Komodo National Park (Figure 2a, b, c, and d).
Figure 1 Map of Komodo National Park and its adjacent coastal area of mainland Flores and Sumbawa
Figure 2 Habitat condition in Loh Liang, Komodo Island (A), Loh Buaya, Rinca Island (B), Cumbi Village,
coastal Flores Island (C), and Sape, coastal Sumbawa Island (D).
Media Konservasi Vol.26 No.3 Desember 2021: 217-230
219
Data were collected at the end of the rainy season in
February-April 2018. We concentrated the survey on the
area within a maximum range of 100 m from water
sources to make sure that we were able to observe
amphibians. A Visual Encounter Survey method (Heyer
et al., 1994) was carried out by randomly walking
through the selected habitat by two-three surveyors. We
actively searched the areas at night (19:00-21:00 Eastern
Indonesian Time) on the forest floor, leaf litter, fallen
logs, water bodies, and surrounding vegetation. During
the day (08:00-10:00), we used a glue trap to capture
small lizards and an active search for other reptiles. We
put ten glue traps (size 30x30 cm) within ± 20 m of each
other in locations that serve as a habitat for basking or
feeding on the forest floor with leaf litter, stones, or
fallen tree trunks. The total effort during the research was
654 person-hours.
We recorded locations, species, and date of capture
at the time of capture. Habitat characteristics were noted.
Frogs and reptiles were released after examination at the
point of capture. Several individuals of amphibian and
reptiles were preserved using 90% alcohol as voucher
specimens, especially for species that have not been
identified. Specimens were stored at the Museum
Zoologicum Bogoriense, Research Centre for Biology,
Indonesian Institute of Sciences (LIPI). There was no
ethical clearance for collecting specimens as no such
document was requested by the park management, other
than permit to collect published by the national park
management. However, we used guidance from Clemann
et al. (2014) for the ethical collection of specimens and
Kusrini (2019) for making specimens in an ethical
manner. Nomenclature follows the reptile database
https://reptile-database.reptarium.cz/ (Uetz and Etzold,
1996) and amphibian species of the world version 6.1
from the American Museum Natural History (AMNH)
https://amphibiansoftheworld.amnh.org/ (Frost, 2020).
We constructed a checklist of amphibians and
reptiles and grouped it based on Red List IUCN
(International Union for Conservation of Nature), CITES
Appendix (Convention on International Trade in
Endangered Species of Wild Fauna and Flora), and
Indonesian Law (Peraturan Menteri Kehutanan and
Lingkungan Hidup nomor 106 Tahun 2018). We
developed an accumulation curve for species obtained
during each periodic survey, thus omitting species
obtained outside sampling time but described in this
report.
We measured diversity indices using the Shannon-
Wiener diversity index (H) (Brower and Zar, 1997),
Evenness (E), and Jackknife estimator for species
richness (S) for each location. Data were analyzed using
program PAST version 3.22 except for the Jackknife
estimator for species richness (S), which was calculated
following Heltse & Forester (1983). The community
similarity index was measured using the Bray-Curtis
index (Bray and Curtis, 1957).
RESULT AND DISCUSSION
1. Species compositions and relative abundance
During the survey, we found 29 species of
herpetofauna (n=671), consisting of 7 species of
amphibians from 4 families and 22 species of reptiles
from 10 families (Table 1). We found two endemic
amphibians (Limnonectes kadarsani and Oreophryne
jeffersoniana) and five endemic reptiles (Draco
boschmai, Dendrelaphis inornatus, Coelognathus
subradiatus, Malayopython timoriensis, and Varanus
komodoensis). Fifteen species are listed as Least Concern
on IUCN Red List, 10 species are Not Evaluated, one
species is listed as Near Threatened (O. jeffersoniana),
and one species is listed as Vulnerable (M. timoriensis),
and one species is listed as Endangered (V.
komodoensis). There are three species listed in Appendix
II CITES: M. reticulatus, M. timoriensis, V. salvator, and
one species is listed in Appendix I CITES, V.
komodoensis (Figure 3).
The cumulative curves for each location differed;
however, it tend to increase in all locations (Fig. 4). This
indicates that there is a possibility that additional
observation will yield other species, i.e., C. subradiatus,
B. hoeseli, N. sputatrix, which have been found by the
first author outside the sampling time of this research.
The Amphibians And Reptiles
220
Figure 3 Endemic species of reptile found during survey Draco boschmai (A), Dendrelaphis inornatus (B),
Coelognathus subradiatus (C), Malayopython timoriensis (D), and Varanus komodoensis (E), except for
Varanus salvator (F), which is listed in CITES Appendix 2
Table 1 Amphibian and reptile community comparison by location, endemicity (E), and conservation status based on
the survey in February April 2018.
No
Spesies
Komodo
Island
Rinca
Island
Coastal
Sumbawa
AMPHIBIANS
Bufonidae
1
Duttaphrynus melanostictus (Schneider, 1799)
-
-
+
Dicroglossidae
2
Fejervarya cancrivora (Gravenhorst, 1829)
-
+
+
3
Fejervarya limnocharis (Gravenhorst, 1829)
-
-
+
4
Fejervarya verruculosaE (Roux, 1911)
-
-
-
5
Limnonectes kadarsaniE (Iskandar, Boeadi, and Sancoyo, 1996)
-
-
-
Microhylidae
6
Kaloula baleata (Muller, 1836)
+
-
+
7
Oreophryne jeffersonianaE (Dunn, 1928)
-
-
-
Rhacoporidae
8
Polypedates leucomystax (Gravenhorst, 1829)
-
-
-
REPTILES
Agamidae/Lizard
1
Draco boschmai (Hennig, 1936)
-
-
+
Gekkonidae/ Gecko
2
Cyrtodactylus darmandvilleiE (Weber, 1890)
+
+
+
3
Hemidactylus frenatus (Dumeril & Bibron, 1836)
+
+
+
4
Hemidactylus platyurus (Schneider, 1797)
+
+
+
5
Gekko gecko (Linnaeus, 1758)
+
+
+
Media Konservasi Vol.26 No.3 Desember 2021: 217-230
221
No
Spesies
Komodo
Island
Rinca
Island
Coastal
Sumbawa
6
Gehyra mutilata (Wiegmann, 1834)
+
-
-
Scincidae/Skink
7
Sphenomorphus melanopogon (Dumeril & Bibron, 1839)
+
+
-
8
Sphenomorphus striolatusE (Weber, 1890)
+
+
+
9
Cryptoblepharus renschi (Mertens, 1928)
+
+
-
10
Emoia similisE (Dunn, 1927)
-
+
-
11
Lamprolepis smaragdina (Lesson, 1829)
-
-
+
Colubridae
12
Lycodon capucinus (Boie, 1827)
+
+
+
13
Dendrelaphis inornatusE (Boulenger, 1897)
+
-
-
14
Coelognathus subradiatusE (Schlegel, 1837)
-
-
+
Elapidae
15
Laticauda colubrina (Schneider, 1799)
+
+
-
Homalopsidae
16
Cerberus schneiderii (Schlegel, 1837)
-
+
-
Pythonidae
17
Malayopython timoriensisE,II, # (Peters, 1876)
-
+
-
18
Malayopython reticulatusII (Schneider, 1801)
-
-
-
Typhlopidae
19
Virgotyphlops braminus (Wallach 2020)
-
+
-
Viperidae
20
Trimeresurus insularis (Kramer, 1977)
+
+
+
Varanidae
21
Varanus komodoensisE, I, *, ^ (Ouwens, 1912)
+
+
-
22
Varanus salvatorII (Laurenti, 1768)
-
+
+
N amphibian species
1
2
5
N reptile species
13
18
11
Number of herpetofauna species
14
20
16
Jackknife index
18
23
20
Note: endemicity (E), conservation status (CITES, IUCN Red List, and Indonesian Government regulation on
Protected species or PP No. 106 MenLHK 2018) for Komodo National Park and its surrounding, Nusa Tenggara,
Indonesia (+ present; - absent). I, II denotes Appendix I and II in CITES, # represents vulnerable in IUCN Red List, *
denotes endangered in IUCN Red List, and ^ denotes protected species
The presence of endemic species and species listed
in threatened categories at IUCN Red List or in the
protected category, i.e., M. timoriensis, V. komodoensis,
and the blue-green T. insularis, which only found in the
Nusa Tenggara region, shows the importance of Komodo
National Park to ensure the existence of herpetofauna
(De Lang, 2011). However, except for V. komodoensis,
which is a protected species and well known, the
presence of endemic snakes is under threat as snakes are
often considered dangerous and thus killed by local
people. During the survey, we encountered a dead T.
insularis, which were most probably killed by the local
people. Based on an interview with locals, the blue-green
variant of T. insularis is often hunted and traded on the
island of Sumbawa (Fig. 5).
The highest relative abundance of species was the
Asian black-spined toad D. melanostictus in Sumbawa
(114.81 ind/100 person-hours, Fig. 6). While the lowest
relative abundance was the smooth-fingered narrow-
mouthed frog Kaloula baleata and the common four-
The Amphibians And Reptiles
222
clawed gecko Gehyra mutilata in Komodo Island (0.36
ind/100 person-hours each). The crab-eating frog Fejervarya cancrivora was the most abundant amphibian
in Rinca and coastal Flores.
Figure 4 Species cumulative curves for amphibians and reptiles for each island
Figure 5 Color differences in Trimeresurus insularis; left: bluish-green color on Komodo Island and right: green
coloration, the common coloration
Figure 6 The Asian black-spined toad (D. melanostictus) (A) is the most abundant toad in Sape (left) and considered a
threat if it arrives in Komodo National Park, while the crab-eating frog (F. cancrivora) (B) might be a new
immigrant to Komodo National Park
A
B
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There has been a concern that the Asian common
toad (Duttaphrynus melanostictus), considered as an
alien species for the eastern part of Indonesia, might have
been distributed in Komodo National Park (Reilly et al.,
2017). However, there is no evidence that the species has
been found in the national park, although it was abundant
in Sape (Kennedi et al., 2020). There is a possibility that
the absence of D. melanostictus in Komodo National
Park is due to its intolerance to salinity and extreme
dryness. Research has shown that D. melanostictus
tadpole is unable to withstand salinity (Strahan, 1953)
compared to F. cancrivora (Dunson, 1977). Research by
Mogali et al. (2017) has shown that the tadpole of D.
melanostictus has the plasticity to adapt with desiccation
by increasing its metamorphic process but at the same
time decreasing its body size. However, Mogali et al.
(2017) showed that the tadpole of D. melanostictus still
needs a minimum threshold period to complete
development, with a minimum of 20 days. The rain-filled
ephemeral water bodies in Komodo and Rinca islands
and Labuan Bajo might not sustain enough time for D.
melanostictus tadpole to survive and metamorphose. On
the contrary, the wet condition of Sape during research
might explain the relatively high abundance of this toad
in the area.
During the survey, the crab-eating frog (F.
cancrivora) was spotted in Loh Buaya and Loh Baru at
Rinca Island (Fig. 6). The first encounter was on 15
March 2018 in Loh Buaya; the frog was calling in the
water-buffalo mud puddle. There are two other records
on the occurrence of this frog. Gilbert (2020) has found
these species in April 2018, and Somaweera et al. (2018)
also reported this species, although it was not clear the
exact location. This species distributes widely in Asia
(Islam et al., 2008) and adapts to a wide range of
salinities (Dunson, 1977). It is unclear whether F.
cancrivora has been established in Rinca for a long time
or is a recent immigrant.
Table 2 Relative abundance (individual/100 person-hours) of herpetofauna at Komodo National Park and its
surrounding areas based on islands. Data for amphibians were reported by Kennedi et al. (2020) but
miscalculated as individual/person-hours.
No
Scientific Name
Komodo Island
Rinca Island
Coastal Flores
Coastal Sumbawa
Amphibians
1
Duttaphrynus melanostictus
-
-
-
114.81
2
Fejervarya cancrivora
-
12.12
66.67
81.48
3
Fejervarya limnocharis
-
-
4.00
9.26
4
Limnonectes kadarsani
-
-
21.33
-
5
Kaloula baleata
0.36
1.21
18.67
3.70
6
Oreophryne jeffersoniana
-
-
5.33
-
7
Polypedates leucomystax
-
-
4.00
5.56
Reptiles
8
Gekko gecko
1.44
1.62
6.67
16.67
9
Hemidactylus frenatus
16.22
7.68
7.68
24.07
10
Hemidactylus platyurus
14.05
8.48
2.67
14.81
11
Gehyra mutilata
0.36
0.81
-
1.85
12
Cyrtodactylus darmandvillei
7.93
5.66
12.00
7.41
13
Sphenomorphus melanopogon
7.21
6.06
6.06
-
14
Sphenomorphus striolatus
9.73
9.29
9.29
1.85
15
Cryptoblepharus renschi
2.52
1.62
1.62
-
16
Emoia similis
-
3.64
-
-
17
Lamprolepis smaragdina
-
-
2.67
-
18
Draco boschmai
-
-
-
1.85
19
Lycodon capucinus
3.60
3.64
1.33
7.41
20
Dendrelaphis inornatus
1.08
0.81
1.33
-
21
Coelognathus subradiatus
-
-
-
1.85
22
Indotyphlops braminus
-
0.81
-
-
23
Trimeresurus insularis
0.72
1.62
28.00
3.70
24
Malayopython timoriensis
-
0.40
-
-
25
Malayopython reticulatus
-
-
1.33
-
26
Cerberus schneiderii
-
-
-
-
27
Laticauda colubrina
-
-
-
-
28
Varanus komodoensis
2.16
1.62
-
-
29
Varanus salvator
-
-
1.33
11.11
The Amphibians And Reptiles
224
The highest abundance of reptiles in Komodo Island
was the common house gecko, Hemidactylus frenatus
followed by the flat-tail gecko H. platyurus, the Flores
banded skink Sphenomorphus striolatus, and Lesser
Sunda dark-throated skink S. melanopogon. All four
species were found in all survey sites on Komodo Island
and also found in coastal Flores and Sumbawa (Table 2,
Fig. 7).
2. Diversity and Community Similarity
The highest index of Shannon-Wiener diversity was
found in Loh Buaya (Rinca Island) (H’=2.42), while the
lowest index was in Komodo Village (H’=1.74). The
highest evenness index was in Sape, while the lowest
was in Rinca Village (E=0.38).
Shannon-Wiener index has been used widely to show
species richness and abundance of ecosystems. It is most
efficient to compare between sites, especially when the
number of species richness is similar (Spellerberg and
Fedor 2003). For instance, the number of species in Sape
was similar to Loh Buaya, but the latter has the highest
diversity due to higher evenness. The value of evenness
in Sape, which was near the end of the spectrum (0.38),
indicates single-species dominance (Stirling and Wilsey
2001), mostly the Asian black spined toad (D.
melanostictus). The environmental conditions might
affect the diversity of amphibian and reptile. The absence
of running water sources might cause a low number of
species in some locations, especially during dry weather
and the lack of rain.
Figure 7 The four most abundant reptiles in Komodo Island: Hemidactylus frenatus (A), H. platyurus (B),
Sphenomorphus striolatus (C), and S. melanopogon (D).
Table 3 Number of species, number of individuals, diversity, and evenness index of herpetofauna of Komodo, Rinca,
coastal Flores, and coastal Sumbawa. Note: KPK=Kampung Komodo, LLG=Loh Liang, LBR=Loh Baru, LBY=Loh
Buaya, KPR=Kampung Rinca, LWU=Loh Wau, CMB=Desa Cumbi, LBJ=Labuan Bajo, and SAP=Sape.
Index
Komodo Island
Rinca Island
Coastal
Flores
Coastal
Sumbawa
KP
K
LL
G
LW
U
LB
Y
KP
R
LB
R
CMB
LBJ
SAP
Number of Species
11
10
8
17
10
14
9
13
17
Number of individuals
66
70
52
71
47
51
85
66
166
Shannon Wiener Diversity Index
(H')
1.74
1.99
1.86
2.42
1.79
2.31
1.87
1.94
1.95
Evenness Index (E)
0.40
0.47
0.47
0.55
0.43
0.59
0.42
0.46
0.38
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Figure 8 Dendrogram of paired group analysis depicting the Bray-Curtis similarity based on the occurrence and
abundance of amphibian and reptile species in all locations.
The Bray-Curtis similarity is primarily used to
quantify the differences in species populations between
different species. Based on figure 8 There were two
clusters of similarity between locations. The Locations at
Komodo Island and Rinca Island belong to one cluster
(with similarity of 0.45), where similar species can be
found in locations within the islands. The similarity of
ecosystems and the close distance between Komodo and
Rinca Islands might explained the higher community
similarity between these islands.
The community assemblages of coastal Flores and
Sumbawa has formed a cluster with low similarity (0.35).
This cluster is linked with Komodo-Rinca Islands cluster
with lower similarity (0.28). The Bray-Curtis similarity
indices distinguished compositional similarity of species
assemblages by matching abundances of species in each
community (Chao et al., 2005). Almost 80% of species
found in Komodo and Rinca Island were found either in
coastal Flores or Sumbawa. However, there were
differences in abundance. In coastal Sumbawa, one
species tended to dominate, whereas there was no
dominance in other locations. The resulting clustering
showed that the community assemblages between
Komodo and Rinca Islands with adjacent coastal areas
differed in abundance.
The number of species on an island is influenced by
the size of the island and the distance to the main island,
which both affect the rate of extinction and immigration
(MacArthur & Wilson, 1967). Flores and Sumbawa,
which are large (main) islands, should have higher
species diversity than smaller islands such as Rinca and
Komodo. However, our sampling was restricted to the
selected coastal area in Flores and Sumbawa, which is
only a tiny part of the entire island. Small islands usually
have fewer species richness than the mainland, which has
been explained by the theory of island biogeography
(MacArthur & Wilson, 1967), as shown in this result.
All species in Rinca and Komodo Island were
distributed either in Flores or Sumbawa, or both. For
instance, V. komodoensis is not only found in Komodo
National Park but also on Flores Island, i.e., Longos
Island, Waewuul Nature Reserve, Tanjung Karita, and
North Flores (Ariefiandy et al. 2021; Ciofi and De Boer,
2014). C. schneiderii, E. similis, I. braminus, and M.
timoriensis were also found in Flores and Sumbawa
(Reilly et al. 2020). Although the occurrence of
amphibian and reptile in Komodo National Park are
mostly secure due to the protected status of the area, it
might be different on the mainland. For instance,
Komodo distribution in Flores is mostly non-protected
areas and at risk from anthropogenic threats (Ariefiandy
et al., 2021; Azmi et al., 2021; Ciofi et al., 2002) and
climate change (Jones et al., 2020).
3. A complete list of reptile and amphibian of
Komodo National Park
Based on this research, combined with the report by
Auffenberg (1980), Wahyuni (2012), and Somaweera et
al. (2018), the herpetofauna of Komodo National Park
comprised of four species of amphibians (Table 4, Figure
6) and 39 species of reptiles (Table 4). Our survey
yielded only two species of amphibian out of three
species reported by Auffenberg (1980) in Komodo Island
The Amphibians And Reptiles
226
and about half of the Komodo Island reptiles and mostly
terrestrial species. O. jeffersoniana, an endemic species
was notably absent during our research in Komodo
Island, although it was recorded in coastal Flores.
Wahyuni (2012) did not find any amphibian in
Padar, a smaller and mostly dry island in Komodo
National Park compared to Komodo and Rinca. Four
species of reptiles reported by Wahyuni (2012) were
absent in Komodo and Rinca island: B. hoeseli, and C.
subradiatus (both endemic of Nusa Tenggara), N.
sputatrix, and C. yulensis. There is a possibility of
misidentification of Wahyuni for C. yulensis. The species
was only reported from Yule Island in Papua New
Guinea (Horner, 2007). No specimens or pictures were
available from Wahyuni’s work; thus, we omitted C.
yulensis from the list of reptiles and amphibian species of
Komodo National Park. A comparison between a list of
herpetofauna published by Auffenberg (1980) on the
Komodo Island showed that our study result was also
lower. From 1969 through 1970, 1971, and 1973,
Auffenberg discovered 30 species of herpetofauna,
whereas our study only found 14 species in Komodo
Island. However, three species found in this study (F.
cancrivora, M. timoriensis, and E. similis) were not
reported by Wahyuni (2012) in Padar or by Auffenberg
(1980) in Komodo Island.
Table 4 List of amphibian and reptile species in three main islands of Komodo National Park based on Auffenberg 1980
(1), Wahyuni 2012 (2), this study (3), and Somaweera et al. 2018 (4).
No
Species
Komodo Island
Rinca Island3
Padar island 2
Komodo NP4
AMPHIBIANS
1
Fejervarya cancrivora
no
yes
no
yes
2
Kaloula baleata
yes3
yes
no
yes
3
Kaloula pulchra
no
no
no
yes
4
Oreophryne jeffersoniana
yes1
no
no
yes
REPTILES
Geckoes
1
Cyrtodactylus darmandvillei
yes1,3
yes
yes
yes
2
Cyrtodactylus laevigatus
yes1
no
no
yes
3
Gehyra mutilata
yes1,3
yes
yes
yes
4
Gekko gecko
yes1,3
yes
yes
yes
5
Hemidactylus frenatus
yes1,3
yes
yes
yes
6
Hemidactylus platyurus
yes1,3
yes
yes
yes
7
Hemiphyllodactylus typus
no
no
no
yes
8
Lepidodactylus lugubris
yes1
no
no
yes
Skinks
9
Cryptoblepharus burdeni
yes1
no
no
yes
10
Cryptoblepharus renschi
yes1,3
yes
yes
yes
11
Emoia similis
yes1
yes
no
yes
12
Eremiascincus emigrans
yes1
no
no
yes
13
Eutropis multifasciata
yes1
no
no
yes
14
Sphenomorphus melanopogon
yes1,3
yes
yes
yes
15
Sphenomorphus schlegeli
yes1
no
yes
yes
16
Sphenomorphus striolatus
yes1,3
yes
yes
yes
Other lizards
17
Draco boschmai
yes1
yes
no
yes
18
Dibamus novaeguineae
yes1
no
no
yes
19
Varanus komodoensis
yes1,3
yes
no
yes
20
Varanus salvator
no
yes
no
yes
Sea turtles
Media Konservasi Vol.26 No.3 Desember 2021: 217-230
227
No
Species
Komodo Island
Rinca Island3
Padar island 2
Komodo NP4
21
Chelonia mydas
yes1
NA
no
yes
22
Eretmochelys imbricata
yes1
NA
no
yes
Crocodiles
23
Crocodylus porosus
yes1
NA
no
yes
Sea snakes
24
Laticauda colubrina
yes1,3
yes
no
yesa
Aquatic snakes
25
Acrochordus granulatus
yes1
NA
no
yes
26
Cerberus schneiderii
yes1
yes
yes
yes
Land and tree snakes
27
Boiga hoeseli
yes1
no
yes
yes
28
Coelognathus subradiatus
yes1
yes
yes
yes
29
Dendrelaphis inornatus
yes1,3
yes
yes
yes
30
Lycodon capucinus
yes1,3
yes
yes
yes
31
Psammodynastes pulverulentus
yes1
no
no
yes
32
Malayopython timoriensis
no
yes
yes
yes
33
Naja sputatrix
yes1
no
no
yes
34
Daboia siamensis
yes1
no
no
yes
35
Trimeresurus insularis
yes1,3
yes
yes
yes
Burrowing snakes
36
Cylindrophis opisthorhodus
no
no
no
yes
37
Indotyphlops braminus
yes1
yes
yes
yes
38
Indotyphlops schmutzi
yes1
no
no
yes
39
Sundatyphlops polygrammicus
yes1
no
no
yes
Note: NA=Not Available (the survey was not carried out in its habitat).
The absence of several species in contrast to
Auffenbergs (1980) was influenced by total search effort
and seasonality. One amphibian and 17 reptiles were
absent in this research as listed in Table 4. Auffenberg
(1980) were based on almost three years fieldwork,
including the rainy season and the dry season, thus
increasing the opportunity to get more species. Our
survey was conducted at the end of the wet season. It is
recommended that other sampling should account for the
rainy season, especially during December-January,
during the highest rainfall, due to the possibility of
different encounters between the rainy season and dry
season.
This survey did not record several marine reptiles’
species because it mostly focused on terrestrial
herpetofauna habitat. Based on Jackknifes calculations,
there was still a possibility that more herpetofauna can be
found on Komodo Island.
CONCLUSION
Our field surveys were recorded 22 species of
reptiles and seven species of amphibians, but only 18
species of reptiles and two species of amphibian were
from Komodo and Rinca Island. All species found in
Komodo, and Rinca Island are also distributed in the
mainland (Flores Island), and 80% of species of Komodo
and Rinca Island were also recorded from coastal Flores
and Sumbawa. The highest Shannon-Wiener diversity
index (2.14) was in Loh Buaya (Rinca). The number of
species in Loh Buaya was similar to Sape in coastal
Sumbawa; however, the evenness index was higher
(0.55) in Loh Buaya, which showed no dominant species
in this area. Komodo National Park is home to 39 species
of reptiles and four species of amphibians. As a
conservation area, this national park is essential to ensure
the survival of herpetofauna. Moreover, it serves as a
habitat for protected species and highly endemic reptiles
from the Lesser Sunda Islands.
The Amphibians And Reptiles
228
ACKNOWLEDGEMENTS
The Komodo Survival Program and University of
Florence provided funding for this research (UFK and
MDK). We thank the Komodo National Park office,
especially the Head of the National Park, Bapak Budi,
and staff of Komodo National Park: M. R. Panggur, B.
Darmawan, and Andan for the assistance. We thank D.
Purwananda and C. Ciofi for their help and advice during
the research. We are grateful for the support of F. S.
Ramadani, Mufti, Adam, pak Sidik, and teachers of SMK
Kelautan Sape for their assistance in the field. Fieldwork
by UFK in the national park has been granted through the
SIMAKSI number SI. 24/T.17/TU/2/2018.
REFERENCES
Ardiantiono, Jessop TS, Purwananda D, Ciofi C, Jeri
Imansyah M, Panggur MR, Ariefiandy A. 2018.
Effects of human activities on Komodo dragons in
Komodo National Park. Biodiversity and
Conservation 27: 33293347.
AmphibiaWeb. 2020. University of California, Berkeley,
CA, USA. https:// https://amphibiaweb.org. [access
date: 29 June 2020].
Ariefiandy A, Purwandana D, Natali C, Imansyah MJ,
Surahman M, Jessop TS, Ciofi C. 2015. Conservation
of Komodo dragons Varanus komodoensis in the
Wae Wuul nature reserve, Flores, Indonesia: a
multidisciplinary approach. International Zoo
Yearbook, 49: 6780.
Ariefiandy A, Purwandana D, Azmi M, Nasu SA,
Mardani J, Ciofi C, Jessop TS. 2021. Human
activities associated with reduced Komodo dragon
habitat use and range loss on Flores. Biodiversity and
Conservation 30:461-79.
Auffenberg W. 1980. The herpetofauna of Komodo, with
notes on adjacent areas. Bulletin of the Florida States
Museum Biological Sciences 25(2): 40-150.
Azmi M, Nasu SA, Kasim AM, Ariefiandy A,
Purwandana D, Ciofi C, Jessop TS. 2021. Incidences
of Road Kills and Injuries of Komodo Dragons Along
the North Coast of Flores Island, Indonesia.
Herpetological Conservation and Biology 16(1): 11
16.
Bray RJ, Curtis JT. 1957. An ordinary of the upland
forest communities of southern Wisconsin. Ecol.
Monogr. 27: 326-349.
Brower JE, Zar JH. 1997. Field and Laboratory Methods
for General Ecology. Brown. Iowa.
Chao A, Chazdon RL, Colwell RK, Shen T-J. 2005. A
new statistical approach for assessing similarity of
species composition with incidence and abundance
data: A new statistical approach for assessing
similarity. Ecology Letters 8: 148159.
Ciofi C, Beaumontf MA, Swingland IR, Bruford MW.
1999. Genetic divergence and units for conservation
in the Komodo dragon Varanus komodoensis.
Proceedings of the Royal Society of London. Series
B: Biological Sciences 266: 22692274.
Ciofi C, De Boer M. 2004. Distribution and conservation
of the komodo monitor (Varanus komodoensis).
Herpetological Journal 14: 99-107.
Ciofi C, Smith BR, Hutchins M. 2002. Conservation in
situ and ex situ contributions. In Komodo Dragon:
Biology and Conservation (eds. Murphy JB, Ciofi C.
De La Panouse C, Walsh T. Smothsonian Institution
Press. Washington. Pp: 211-230.
Clemann N, Rowe KM, Rowe KC, Raadik T, Gomon M,
Menkhorst P, Sumner J, Bray D, Norman M, Melville
J. 2014. Value and impacts of collecting vertebrate
voucher specimens, with guidelines for ethical
collection. Memoirs of Museum Victoria 72: 141
151.
De Lang R. 2011. The snake of the lesser sunda island
(Nusa Tenggara) Indonesia. Asian Herpetological
Research 2(1): 46-54.
Dunson WA. 1977. Tolerance to high temperature and
salinity by tadpoles of the Philippine frog, Rana
cancrivora. Copeia 1977: 375378.
Frost DR. 2020. Amphibian Species of the world Ver
6.1.
https://amphibiansoftheworld.amnh.org/index.php.
[access date: 29 June 2020].
Gilbert JB, Ocock J, Martinez CAP, Riley JL. 2020.
Fejervarya cancrivora (Crab-eating frog) Dunging
(Natural History Notes). Herpetological review 51(1):
97-98.
Heltse JF, Forester NE. 1983. Estimating species
richness using the jackknife procedure. Biometrics
39: 1-11.
Heyer WR, Donnelly MA, McDiarmid RW, Hayek LC,
Foster MS. 1994. Measuring and Monitoring
Biological Diversity: Standard Methods for
Amphibians. Smithsonian Institution Pr. Washington
DC.
Horner P. 2007. Systematics of the snake-eyed skinks,
Cryptoblepharus Wiegmann (Reptilia: Squamata:
Scincidae) an Australian-based review. The Beagle,
Records of the Museums and Art Galleries of the
Northern Territory Supplement 3: 21198.
Hulme PE, Bacher S, Kenis M, Klotz S, Kuhn I, Minchin
D, Nentwig W, Olenin S, Panov V, Pergl J, Pysek P,
Roques A, Sol D, Solarz W, Vila M. 2008. Grasping
at the routes of biological invasions: a framework for
integrating pathways into policy. Journal of Applied
Ecology 45: 403-414.
Islam MM, Kurose N, Khan MMR, Nishizawa T,
Kuramoto M, Alam MS, Hasan M, Kurniawan N,
Nishioka M, and Sumida M. 2008. Genetic
divergence and reproductive isolation in the genus
Fejervarya (Amphibia: Anura) from Bangladesh
inferred from morphological observations, crossing
experiments, and molecular analyses. Zool Sci 25:
1084-1105.
Media Konservasi Vol.26 No.3 Desember 2021: 217-230
229
Jones AR, Jessop TS, Ariefiandy A, Brook BW, Brown
SC, Ciofi C, Benu YJ, Purwandana D, Sitorus T,
Wigley TML, Fordham DA. 2020. Identifying island
safe havens to prevent the extinction of the World’s
largest lizard from global warming. Ecology and
Evolution 10: 1049210507.
Jessop TS, Ariefiandy A, Purwandana D, Ciofi C,
Imansyah J, Benu YJ, Fordham DA, Forsyth DM,
Mulder RA, Phillips BL. 2018. Exploring
mechanisms and origins of reduced dispersal in
islands Komodo dragons. Proc. R. Soc. B 285:
20181829.
Kennedi UF, Kusrini MD, Mardiastuti A, Ariefiandy A.
2020. Invasive toads are close to but absent from
Komodo National Park. BIO Web of Conferences
19(1): 00017.
Kusrini MD. 2013. Panduan Bergambar Identifikasi
Amfibi Jawa Barat. Fakultas Kehutanan IPB. Bogor.
MacArthur RH, Wilson EO. 1967. The Theory of Island
Biogeography. Princeton University Press. Princeton.
Mogali S, Saidapur S, Shanbhag B. 2017. Influence of
desiccation threat on the metamorphic traits of the
Asian common toad, Duttaphrynus melanostictus
(Anura). Acta Herpetologica 12 (2): 175-180.
Monk KA, De Freter, Reksodihardjo G, Lilley. 1997. The
Ecology of Nusa Tenggara and Maluku (The Ecology
of Indonesia Series Volume V). Periplus edition.
Singapore.
Purwandana D, Ariefiandy A, Imansyah M., Seno A,
Ciofi C, Letnic M, Jessop TS. 2016. Ecological
allometries and niche use dynamics across Komodo
dragon ontogeny. The Science of Nature 103(3-4): 1-
11.
Reilly SB, Wogan G, Arida E, Iskandar DT, McGuire J.
2017. Toxic toad invasion of Wallacea: a biodiversity
hotspot characterized by extraordinary endemism.
Global Change Biology 23(12): 1-3.
Reilly SB, Stubbs AL, Arida E, Arifin U, Bloch L,
Hamidy A, Harmon K, Hykin S, Karin BR,
Ramadhan G, Iskandar DT, McGuire JA. 2020. New
Island Records for Anurans and Squamates from the
Lesser Sunda Archipelago. Herpetological Review
51(4): 785789.
Somaweera R, Azis A, Resa E, Panggur MR, Saverinus
D, Muga K. 2018. Amphibians and Reptiles of
Komodo National Park. Aaranya Wildlife Odysseys.
Australia.
Spellerberg IF, Fedor PJ. 2003. A tribute to Claude
Shannon (19162001) and a plea for more rigorous
use of species richness, species diversity, and the
‘Shannon–Wiener’ Index. Global Ecology &
Biogeography 2003: 177179.
Stirling G, Wilsey B. 2001. Empirical relationships
between species richness, evenness, and proportional
diversity. The American Naturalist 158 (3): 286299.
Strahan R. 1953. The effect of salinity on the survival of
larvae of Bufo melanostictus Schneider. Copeia
1957(2): 146147.
Uetz P, Etzold T. 1996. The EMBL/EBI reptile database.
Herpetological Review 27(4): 174-175.
Wahyuni SR. 2012. Keanekaragaman jenis and sebaran
spasial reptil di Pulau Padar, Taman Nasional
Komodo. Skripsi. Institut Pertanian Bogor. Bogor.
The Amphibians And Reptiles
230
APPENDICES
Appendix 1. Specimens deposited at Museum Zoological Bogor (MZB).
No
Species
Code
MZB
Site
Island
1
Cryptoblepharus renschi
Lace
14906
Loh Wau
Komodo
2
Cryptoblepharus renschi
Lace
14907
Loh Wau
Komodo
3
Cyrtodactylus darmandvillei
Lace
14897
Kp. Komodo
Komodo
4
Cyrtodactylus darmandvillei
Lace
14898
Loh Liang
Komodo
5
Sphenomorphus melanopogon
Lace
14903
Kp. Komodo
Komodo
6
Sphenomorphus melanopogon
Lace
14904
Loh Buaya
Rinca
7
Sphenomorphus striolatus
Lace
14901
Kp. Komodo
Komodo
8
Sphenomorphus striolatus
Lace
14905
Loh Buaya
Rinca
9
Sphenomorphus striolatus
Lace
14902
Loh Buaya
Rinca
10
Emoia similis
Lace
14908
Loh Buaya
Rinca
11
Emoia similis
Lace
14909
Loh Buaya
Rinca
12
Gehyra mutilata
Lace
14910
Sape
Sumbawa
13
Hemidactylus frenatus
Lace
14899
Kp. Komodo
Komodo
14
Hemidactylus frenatus
Lace
14900
Kp. Komodo
Komodo
15
Lycodon capucinus
Ophi
6237
Loh Liang
Komodo
16
Indotyphlops braminus
Ophi
6236
Loh Buaya
Rinca
17
Duttaphrynus melanostictus
Amph
31740
Sape
Sumbawa
18
Duttaphrynus melanostictus
Amph
31741
Sape
Sumbawa
19
Fejervarya cancrivora
Amph
31738
Loh Buaya
Rinca
20
Fejervarya verruculosa
Amph
31739
Labuan Bajo
Flores
21
Kaloula baleata
Amph
31742
Loh Buaya
Rinca
22
Limnonectes kadarsani
Amph
31743
Wae Wuul
Flores
23
Limnonectes kadarsani
Amph
31744
Wae Wuul
Flores
24
Oreophryne jeffersoniana
Amph
31745
Wae Wuul
Flores
25
Polypedates leucomystax
Amph
31746
Labuan Bajo
Flores
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Phenotypic plasticity of metamorphic traits, in response to desiccation threat, was studied in Duttaphrynus melanostictus under laboratory conditions. Newly hatched Gosner stage 19 tadpoles were exposed to decreasing water levels (gradually or rapidly) up to the beginning of metamorphic climax (MC, Gosner stage 42). The control group was reared in unchanging water levels. The tadpoles experiencing desiccation threat reached MC earlier than those reared in constant water levels and metamorphosed (Gosner stage 46) at smaller body sizes. Time to reach MC was comparable between the groups of tadpoles experiencing a gradual or rapid decrease in water levels but their size at the completion of metamorphosis varied. They emerged at a significantly smaller size under rapid desiccation threat compared to the gradual desiccation threat. Impact on size at emergence was in proportion to the level of desiccation threat and this accelerated development and led to an early metamorphosis. The study shows the ability of D. melanos-tictus for developmental plasticity under adverse ecological conditions like the desiccation threat.
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Invasions of poisonous species can cause rapid population declines among native fauna because predators are naïve and often vulnerable to these toxins. The recent invasion of Madagascar by the poisonous Asian common toad, Duttaphrynus melanostictus, has sparked international attention (Kolby, 2015), as well as research and conservation efforts to predict the climate suitability of Madagascar for the invasive toads (Pearson 2015; Vences et al., 2017), pinpoint the origin of the invasive lineage (Wogan et al., 2016; Vences et al., 2017), determining the toads’ distribution, and educating local communities (Andreone, 2014). While the invasion in Madagascar has received much attention, an invasion of this same toad species on the islands of Wallacea in eastern Indonesia is ongoing but virtually unrecognized. This article is protected by copyright. All rights reserved.