| Citation |
IUCN SSC Amphibian Specialist Group 2018. Platymantis diesmosi. The IUCN Red List of Threatened Species 2018: e.T136008A58483258. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T136008A58483258.en. Downloaded on 14 May 2019. |
Description |
Geographic Range
NATIVE
Extant (resident)
Philippines
NUMBER OF LOCATIONS
2
UPPER ELEVATION LIMIT
1,350 metres
LOWER ELEVATION LIMIT
900 metres
Geographic Range in detail
ESTIMATED AREA OF OCCUPANCY (AOO) (KM²)
CONTINUING DECLINE IN AREA OF OCCUPANCY (AOO)
EXTREME FLUCTUATIONS IN AREA OF OCCUPANCY (AOO)
ESTIMATED EXTENT OF OCCURRENCE (EOO) (KM²)
121.14
CONTINUING DECLINE IN EXTENT OF OCCURRENCE (EOO)
EXTREME FLUCTUATIONS IN EXTENT OF OCCURRENCE (EOO)
CONTINUING DECLINE IN NUMBER OF LOCATIONS
EXTREME FLUCTUATIONS IN THE NUMBER OF LOCATIONS
RANGE DESCRIPTION
This species is thus far only known from Mount Malinao, in the municipalities of Tiwi and Malinao, Albay Province, on the Bicol Peninsula, in the south of Luzon Island, in the Philippines, between 900–1,350 m asl (Brown and Gonzalez 2007, Philippine Red List Assessment Workshop May 2017). It is presumed to have a small distribution, but might occur more widely on the central geological component of the Bicol peninsula (for example on Mounts Isarog, Bulusan and Labo). It could possibly occur even further afield on Catanduanes and the Caramoan Peninsula. Its extent of occurrence (EOO) is 121 km2.
Population
CURRENT POPULATION TREND
Decreasing
NUMBER OF MATURE INDIVIDUALS
POPULATION SEVERELY FRAGMENTED
No
CONTINUING DECLINE OF MATURE INDIVIDUALS
Population in detail
EXTREME FLUCTUATIONS
NO. OF SUBPOPULATIONS
CONTINUING DECLINE IN SUBPOPULATIONS
EXTREME FLUCTUATIONS IN SUBPOPULATIONS
ALL INDIVIDUALS IN ONE SUBPOPULATION
NO. OF INDIVIDUALS IN LARGEST SUBPOPULATION
DESCRIPTION
It is relatively abundant locally where it has been recorded. Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
Habitat and Ecology
SYSTEM
Terrestrial
HABITAT TYPE
Rocky areas (eg. inland cliffs, mountain peaks), Forest
GENERATION LENGTH (YEARS)
CONGREGATORY
MOVEMENT PATTERNS
Not a Migrant
CONTINUING DECLINE IN AREA, EXTENT AND/OR QUALITY OF HABITAT
Yes
Habitat and Ecology in detail
HABITAT AND ECOLOGY
This species is currently known only from mid-elevational transitional forest between lower- and mid-montane dipterocarp forest communities (Brown and Gonzalez 2007). Calling males exhibit a microhabitat preference unique among similar species, calling solely from the edge of steep cliffs along deep arroyo-like creek ravines (Brown and Gonzalez 2007). During surveys on Mount Malinao, biologists spent several weeks at the lower edge of the forest (ca 700–800 m asl) and at higher elevations between the type locality and the mountain’s peak (1,550 m asl), but the species was only encountered between 900–1,160 m asl (Brown and Gonzalez 2007). It has not been found outside forest. It is presumed to breed by direct development without dependence on water.
CLASSIFICATION SCHEME
Habitats Suitability Major importance
1. Forest 1.6. Forest - Subtropical/Tropical Moist Lowland Suitable Yes
1.9. Forest - Subtropical/Tropical Moist Montane Suitable Yes
6. Rocky areas (eg. inland cliffs, mountain peaks)
Threats
Agriculture & aquaculture
Annual & perennial non-timber crops
Biological resource use
Logging & wood harvesting
Threats in detail
THREATS
The available evidence suggests that this species is restricted to a single habitat type: the transition zone between lower- and mid-montane dipterocarp forests (Brown and Gonzalez 2007). Near the type locality, extensive slash-and-burn shifting agriculture and selective logging is taking place throughout mid-montane elevations on Mount Malinao (Brown and Gonzalez 2007). In 2001, the type locality was barely 100 m above some of the most severe disturbances on the eastern face of Mount Malinao, and it is feared that continued degradation of the forest edge at this site will soon extend upwards to the type locality (Brown and Gonzalez 2007). Because this area also supplies the majority of freshwater to the municipality of Tiwi, continued and unchecked exploitation of this fragile transition zone habitat will threaten not only the continued existence of the species, but also the future availability of freshwater for humans in the Tiwi watershed (Brown and Gonzalez 2007). In addition to agricultural expansion, extensive timber poaching is taking place within the forest.
CLASSIFICATION SCHEME
Threats Timing Stresses Scope Severity Impact score Invasive species Virus
2. Agriculture & aquaculture 2.1. Annual & perennial non-timber crops 2.1.1. Shifting agriculture Ongoing
1. Ecosystem stresses 1.1. Ecosystem conversion
1.2. Ecosystem degradation
2.1.2. Small-holder farming Ongoing
1. Ecosystem stresses 1.1. Ecosystem conversion
1.2. Ecosystem degradation
5. Biological resource use 5.3. Logging & wood harvesting 5.3.5. Motivation Unknown/Unrecorded Ongoing
1. Ecosystem stresses 1.2. Ecosystem degradation |
