| Citation |
IUCN SSC Amphibian Specialist Group 2018. Ichthyophis weberi. The IUCN Red List of Threatened Species 2018: e.T59606A114869780. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T59606A114869780.en. Downloaded on 10 May 2019. |
Description |
Geographic Range
NATIVE
Extant (resident)
Philippines
NUMBER OF LOCATIONS
2
UPPER ELEVATION LIMIT
LOWER ELEVATION LIMIT
UPPER DEPTH LIMIT
LOWER DEPTH LIMIT
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)
1360
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
The type locality of the species is the vicinity of the Malatgan (also known as the Malatgao) River in Iwahig, on Palawan Island in the Philippines (Taylor 1920). In 1961, the species was recorded at Thumb Peak, which represents the southernmost part of its known range (California Academy of Sciences herpetological database; Philippines Red List Assessment Workshop May 2017). In 2015, it was recorded in Cleopatras Needle and it may be more widespread (Philippines Red List Assessment Workshop May 2017). Its elevational range is unknown, and its extent of occurrence (EOO) is 1,360 km2.
Population
CURRENT POPULATION TREND
Decreasing
NUMBER OF MATURE INDIVIDUALS
POPULATION SEVERELY FRAGMENTED
Unknown
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
Targeted field surveys since 1994, including surveys of five different forested sites across Palawan (conducted between 2003 and 2005) failed to record the species (Diesmos 2012). In 2015, it was recorded in the forests of Cleopatras Needle after not being observed since 1961 at Iwahig, Palawan (van Beijnen et al. in press). Either this species is truly rare or a combination of sampling methods is necessary in order to detect it (Diesmos 2012). Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
Habitat and Ecology
SYSTEM
Terrestrial, Freshwater (=Inland waters)
HABITAT TYPE
Forest, Wetlands (inland)
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 inhabits riverine habitats (usually river banks) in lowland forest, where the adults are likely to be subterranean. In 2015, an individual was found 20 m away from a river on the surface in leaf litter around tree roots (Philippines Red List Assessment Workshop May 2017). Its breeding strategy is unknown, however it is presumably oviparous with terrestrial eggs and aquatic larvae.
CLASSIFICATION SCHEME
Habitats Suitability Major importance
1. Forest 1.6. Forest - Subtropical/Tropical Moist Lowland Suitable Yes
5. Wetlands (inland) 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls) Suitable Yes
5.2. Wetlands (inland) - Seasonal/Intermittent/Irregular Rivers/Streams/Creeks Suitable Yes
Threats
Agriculture & aquaculture
Annual & perennial non-timber crops
Energy production & mining
Mining & quarrying
Pollution
Agricultural & forestry effluents
Threats in detail
THREATS
The greatest threat to Philippine caecilians is habitat destruction, particularly of lowland forests, resulting in degradation of streams and creeks (Diesmos 2012). Potential threats to the species are slash-and-burn farming, mining and habitat conversion for agriculture, including within the limits of the Cleopatras Needle Critical Habitat (Philippines Red List Assessment Workshop May 2017), though suitable habitats still remain for this species on Palawan (Diesmos 2012). Also in Cleopatras Needle is the practice of sap-harvesting from Agathis trees (Philippines Red List Assessment Workshop May 2017), however these activities occur on mountain slopes at higher altitudes are not thought to be impacting this species (J. van Beijnen pers. comm. 2017). Threats are reduced at the Malatgan River site due to the presence of a government-run penal colony which limits the land uses (although parts of it are developed and being cleared for agricultural activities) and potentially maintains some of the forest habitat (Philippines Red List Assessment Workshop May 2017).
CLASSIFICATION SCHEME
Threats Timing Stresses Scope Severity Impact score Invasive species Virus
2. Agriculture & aquaculture 2.1. Annual & perennial non-timber crops 2.1.4. Scale Unknown/Unrecorded Ongoing
1. Ecosystem stresses 1.1. Ecosystem conversion
1.2. Ecosystem degradation
Low Impact: 3
3. Energy production & mining 3.2. Mining & quarrying Ongoing
1. Ecosystem stresses 1.2. Ecosystem degradation
Low Impact: 3
9. Pollution 9.3. Agricultural & forestry effluents 9.3.4. Type Unknown/Unrecorded Ongoing
1. Ecosystem stresses 1.2. Ecosystem degradation
Low Impact: 3
Use and Trade
Use and Trade in detail
USE AND TRADE
At present, there are no indications that the burgeoning illegal wildlife trade on Palawan has a direct impact on the species (Diesmos 2012). |
