Notes on the forest frogs of Cleopatra's Needle Mountain Range, with special reference to the newly defined and expanded geographical range of Pelophryne albotaeniata (Barbour, 1938): fuel for the conservation of the forests of northern Palawan Island, Philippines

Abstract

Cleopatra's Needle Mountain Range, in northern Palawan, holds some of the last naturally forested habitat, supporting a significant number of locally endemic amphibians. As preparation for a new conservation program focused on this remote mountain range, a preliminary visual herpetological survey was undertaken to gather initial data on amphibian populations from this biogeographically distinct region. Eleven frog species were documented during this study including the Palawan Toadlet, Pelophryne albotaeniata (Barbour, 1938). To date, Cleopatra's Needle is the fourth published locality for this species and the first record for the species in northern Palawan thereby extending the range of the species significantly. Other endemic amphibians recorded during our survey include; Barbourula busuangensis, Ingerophrynus philippinicus, Limnonectes acanthi, Hylarana moellendorffi, Sanguirana sanguinea, Leptobrachium tagbanorum, Megrophrys ligayae, Philautus longicrus, Staurois nubilus and the widespread Asian tree frog Polypedates macrotis.

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Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
Notes on the forest frogs of Cleopatra’s Needle Mountain Range, with special
reference to the newly defined and expanded geographical range of Pelophryne
albotaeniata (Barbour, 1938): fuel for the conservation of the forests of
northern Palawan Island, Philippines
Edgar D. Jose1 and Jonah van Beijnen1
1 Centre for Sustainability, Sta. Lucia, Puerto Princesa City, Palawan, Philippines
Email: edgar@centreforsustainability.org; jonah.vanbeijnen@gmail.com
ABSTRACT: Cleopatra’s Needle Mountain Range, in northern Palawan, holds some of the last naturally
forested habitat, supporting a significant number of locally endemic amphibians. As preparation for a new
conservation program focused on this remote mountain range, a preliminary visual herpetological survey
was undertaken to gather initial data on amphibian populations from this biogeographically distinct
region.
Eleven frog species were documented during this study including the Palawan Toadlet, Pelophryne
albotaeniata (Barbour, 1938). To date, Cleopatra’s Needle is the fourth published locality for this species
and the first record for the species in northern Palawan thereby extending the range of the species
significantly.
Other endemic amphibians recorded during our survey include; Barbourula busuangensis, Ingerophrynus
philippinicus, Limnonectes acanthi, Hylarana moellendorffi, Sanguirana sanguinea, Leptobrachium
tagbanorum, Megrophrys ligayae, Philautus longicrus, Staurois nubilus and the widespread Asian tree
frog Polypedates macrotis.

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
INTRODUCTION
The Philippine island province of Palawan (approximately 12,000 km2) is located in the southwest portion
of the archipelago, its southern reaches adjacent to Borneo Island, to which it once might have been
connected (Reis & Garong, 2001). Due to Palawan’s relatively low human population density, the island
has been spared the catastrophic deforestation that has taken place in the rest of the country (Widmann
et al.2008). In contrast to the rest of the Philippine archipelago, for which estimates of remaining original
forest range from 4–12% (DENR, 2012), approximately 40 - 50% of the primary forests of Palawan remain
at present (Baltazar, 1997). Nevertheless Palawan’s forests are currently being threatened by the rapid
urban development on the island.
Although the prevailing biogeographic paradigm considers Palawan to be a relatively young island (Matsui
et al., 2010), recent research has gathered evidence for a much older cretaceous origin of Palawan (Walia
et al., 2012). Additionally, Palawan’s hypothesized repeated connection to the landmasses of the Sunda
shelf (Esselstyn et al., 2010) has resulted in an interesting evolutionary experiment leading to a terrestrial
vertebrate diversity with very high levels of endemism ( Diesmos et al., 2002; Esselstyn et al., 2010; Inger
& Voris, 2001).
The importance of Palawan was further highlighted with its international recognition by the United
Nations Educational, Scientific and Cultural Organization (UNESCO) as a Biosphere Reserve containing two
World Heritage Sites, namely The Puerto Princesa Subterranean River National Park and the Tubbataha
Reefs Natural Park (Baltazar, 1997). However, because of bureaucratic obstacles to biodiversity field
research the island remains relatively understudied (Brown personal communication, 2014).

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
Palawan is home to at least 23 species of amphibians (Biju et al., 2007; Diesmos & Brown 2011; Diesmos
et al., 2005) of which at least ten species are endemic to the province (Sanguila et al., 2011; Matsui et al.,
2010). Palawan endemic amphibians include several species that are listed as threatened including the
Palawan Horned Frog (Megophrys ligayae, Taylor, 1920), the Philippine Flat-headed Frog (Barbourula
busuangensis, Taylor and Noble, 1924) and the Palawan Toadlet (Pelophryne albotaeniata, Barbour 1938).
The Palawan Horned Frog and the Palawan Toadlet are listed as Endangered in the IUCN red list (IUCN,
2015), while Barbourula busuangensis is currently listed as Vulnerable but this status will most probably
be upgraded to “Endangered” in a pending revision of the IUCN conservation status assessment for this
species (Diesmos personal communication, 2014; IUCN, 2015).
The Cleopatra’s Needle Mountain Range, in northern Palawan, is one of the last “stronghold” habitats for
the island’s locally endemic species as the forest covering the mountain has remained relatively
undisturbed as shown in Fig. 4. In conjunction with a new intended conservation program by the Centre
for Sustainability, a Palawan-based conservation group, for this remote mountain range, an initial visual
rapid assessment survey was undertaken to gather more data on the amphibians in the area. Here we
report on the species encountered, and undertake particular reference to the newly expanded
geographical range of Pelophryne albotaeniata, a species much more widely distributed than previously
thought.
MATERIALS AND METHODS
While trekking to the peak of the Cleopatra’s Needle on 3 – 8 January 2014, rivers, creeks and adjacent
forests were opportunistically visually surveyed for amphibians using passive encounter surveys and
incidental observations (Eekhout, 2010) during the daily 8 hour hikes. Visual surveys were only performed
during the day while following a predetermined route from Barangay San Rafael, following the Tanabag

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
River, then summiting the peak of Cleopatra’s Needle at 1593 meters above sea level (MASL) via an
approach from the eastern flank of the mountain. The team consisted of the two authors and three
colleagues of the Batak tribe. All encountered amphibian species were documented through photographs
only and no specimens were collected. Specimens were identified by photographs using literature (Brown
et al., 2009; Das, 2008; Diesmos & Brown, 2011; Diesmos et al., 2002) and through identification by
experts via email (Diesmos & Brown, 2014).
RESULTS AND DISCUSSION
A total of 11 amphibian species were encountered during our brief survey. Ten of these species are locally
endemic; and one is known to occur throughout Southeast Asia (Table 1).
Table 1: Amphibian species encountered during the survey at Cleopatra’s Needle Mountain Range, Palawan.
Species
Habitat
Extent of
Occurrence
Barbourula busuangensis
Lowland riverine forest streams (aquatic)
Palawan
Ingerophrynus philippinicus
Lowland forest and disturbed areas
Palawan
Pelophryne albotaeniata
Cloud forest
Palawan
Limnonectes acanthi
Riverine forest and streams
Palawan
Leptobrachium tagbanorum
Lowland riverine forest
Palawan
Megophrys ligayae
Lowland to montane forest
Palawan
Hylarana moellendorffi
Lowland riverine forest
Palawan
Sanguirana sanguinea
Lowland forest
Palawan
Staurois nubilus
Lowland forest
Palawan
Philautus longicrus
Lowland to montane forest
Palawan
Polypedates macrotis
Forest and disturbed habitats
Southeast Asia
Among the findings, the recording of the Palawan Toadlet (Pelophryne albotaeniata) was most notable.
Pelophryne albotaeniata was originally described from Thumb Peak (the type locality) by Barbour in 1938
(Barbour, 1938; Inger, 1954; Inger, 1960) at an altitude of 4500 feet (which is noteworthy as the mountain

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
measures only 1296 meter, approximately 4250 feet) with a second locality recorded by Wemer (1947)
for Mount Balabag (located in the Mantalingahan Mountain Range). Although the IUCN red list details
the research on the species as “no field observations of this species for more than 40 years” (IUCN, 2015),
a third locality was confirmed by Brown et al. (2007) at Mount Mantalingahan. To date, Cleopatra’s Needle
is the fourth recorded locality for the species, which is a significant northern Palawan range extension (Fig.
1), especially given the paucity of records for the species over the past 75 years since its discovery
(Barbour, 1938).
Fig.1: Map of the Philippines (inset) and the three main recorded localities of Pelophryne albotaeniata
in Palawan, Philippines.
On 7 January 2014, four Palawan Toadlets, Pelophryne albotaeniata (Barbour, 1938), were encountered
at elevations ranging from 1400 to 1580 meter above sea level. The species was recorded in the two types
of vegetation present at this altitude; the first vegetation type consists of fine leaved bamboo species

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
(Bambusa species) at elevations from 1400 to 1475 MASL, and the second vegetation type is mature cloud
forest (dominated by Quercus species) at approximately 1475 MASL, which persists till the peak (1593
MASL).
The first individual of Pelophryne albotaeniata was encountered calling (10:20 AM), resting (Fig. 2a,b) in
bamboo leaf litter, the second individual was found in the same bamboo dominated vegetation. Later in
the morning, two individuals (Fig. 2c) were encountered perched in lichen of a tree trunk (Quercus
species), in cloud forest at approximately 1490 MASL at 1.5 – 1.8 m above the ground. It is interesting to
note that one of these individuals feigned death upon discovery (as the specimen was approached for
photographing purposes) and it jumped from the tree landing on its back and remaining motionless for
about 1 minute (Fig 2d). Both individuals that were found perched in a tree, exhibited a clear black spotted
pattern on the ventral surface (Fig. 2d). Additionally these two specimens did not possess the parallel
polymorphic white colored stripes, which were previously identified as diagnostic for this species
(Barbour, 1938; Inger, 1954; Inger, 1960) and that we found on the specimens found in the bamboo forest.
Fig. 2a: Typical walking posture of Pelophryne albotaeniata; Fig. 2b: Pelophryne albotaeniata in calling
posture, Fig. 2c: Pelophryne albotaeniata lacking diagnostic while lateral stripes (Barbour, 1938; Inger,
1954), Fig. 2d: Pelophryne albotaeniata showing its spotted ventrum after jumping from a small tree
(© Jonah van Beijnen).

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
Although previous studies have used the two parallel polymorphic white colored stripes along the
dorsolateral body surface as diagnostic characters (Barbour, 1938; Inger, 1954; Inger, 1960), we suspect
that color variation observed here is indicative of sex, ontogenetic, or inter-population variation. Further
study of geographic variation in color variation of the species will be required to distinguish between these
hypotheses.
CONCLUSION AND RECOMMENDATION
The occurrence of Pelophryne albotaeniata and the presence of other locally endemic amphibian species
are indicators of a viable and intact forest ecosystem in northern Palawan. Taking into consideration the
‘Endangered’ and ‘Vulnerable’ IUCN conservation status of three recorded species, Cleopatra’s Needle
Mountain Range can be considered a key area for amphibian species conservation in the Palawan faunal
region. The first step in this conservation effort is enlisting local stakeholders in public education,
sustainable use of forest resources, and establishment of administratively formalized protected area
status for the Cleopatra’s Needle Mountain Range.
Additional research is needed to increase our understanding about of population status and conservation
biology of Pelophryne albotaeniata and other amphibians in northern Palawan. The genetic relationships
of the population of P. albotaeniata on Cleopatra’s Needle (northern Palawan), the original type locality
(Thumb Peak, central Palawan) and Mt. Mantalingahan Mountain Range (Southern Palawan) should be
investigated to get a clearer picture about the relationship between these populations in an effort to gain
more understanding about the biogeography and dispersal of amphibians on the island.
It is our hope that the results of this initial survey will trigger further research and conservation action
focused on the amphibians at Cleopatra’s Needle and other parts of Palawan. As updated field surveys

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
and new distributional data have become available elsewhere in the archipelago (Siler et al., 2011; Siler
et al., 2012; Devan-Song & Brown, 2012; Diesmos et al., 2005; Diesmos et al, 2002), Palawan amphibian
studies have conspicuously lagged behind due to bureaucratic obstacles to research (Brown personal
communication, 2014). Great strides could be made if a comprehensive Palawan faunal region amphibian
biodiversity inventory (and full taxonomic and conservation status assessment) were undertaken in a
coordinated fashion in the years to come.
ACKNOWLEDGEMENTS
The preliminary herpetological survey at the Cleopatra’s Needle Mountain Range was made possible
through the financial contributions of the Centre for Sustainability for an upcoming conservation program
in collaboration with Rainforest Trust, Global Wildlife Conservation and the Amphibian Survival Alliance.
We especially thank Samuel, Tirso and Oliver from the Batak tribe of Kalakwasan for their assistance in
the field and Dr. Rafe Brown for his feedback on the manuscript.

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
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APPENDIX
Fig. 3: Amphibian species encountered during the visual survey at Cleopatra’s Needle, Palawan.

Journal of Natural History – National Museum of the Philippines, Volume 2 (2017) ISSN 2013-2001, page 33- 37.
Fig. 4: Aerial shot of Cleopatra’s Needle, Palawan (© Jonah van Beijnen).