Rhyacornis bicolor 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Muscicapidae

Scientific Name: Rhyacornis bicolor
Species Authority: (Ogilvie-Grant, 1894)
Common Name(s):
English Luzon Water-redstart, Luzon Water Redstart, Luzon Redstart, Luzon Water-Redstart, Philippine Water-redstart
Identification information: 15 cm. Small, blue-and-orange chat restricted to riparian habitats. Male has dark slaty-blue upperparts, tinged brown on wings. Deep orange-chestnut uppertail-coverts, tail, belly and vent. Dark bare parts. Female similar though duller with brownish uppertail-coverts and tail. Voice Shrill high-pitched whistles.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2c+3c+4c;D2 ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Allen, D.
Facilitator/Compiler(s): Benstead, P., Derhé, M., Gilroy, J.
This species qualifies as Vulnerable because it has a very small range, and rather strict ecological requirements that are likely to make it more sensitive to habitat loss and degradation, resulting in rapid population declines.

Previously published Red List assessments:
2008 Vulnerable (VU)
2006 Vulnerable (VU)
2004 Vulnerable (VU)
2000 Vulnerable (VU)
1996 Endangered (EN)
1994 Endangered (EN)
1988 Threatened (T)

Geographic Range [top]

Range Description: Rhyacornis bicolor is endemic to the Philippines, where it occurs principally in the Cordillera Central and also the Sierra Madre mountains on Luzon. There are two recently discovered 1960s records from central Mindoro. Overall it is uncommon and probably declining, owing to its restricted habitat use within a limited range. Nevertheless, it appears to be locally common, with pairs separated by intervals of only 200-300 m along suitable streams on Mt Polis, and reports of it being common in Kalinga (D. Allen in litt. 2012). although evidence suggests that in some places its occurrence may be spatially and temporally patchy.

Countries occurrence:
Continuing decline in area of occupancy (AOO): Yes
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 29100
Continuing decline in extent of occurrence (EOO): Yes
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 2-5
Continuing decline in number of locations: Yes
Extreme fluctuations in the number of locations: No
Lower elevation limit (metres): 300
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The population is estimated to number 2,500-9,999 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend Justification:  Rapid population declines are suspected to be occurring in line with rates of habitat degradation, accentuated by the species's strict habitat requirements and sensitivity to environmental change.
Current Population Trend: Decreasing
Additional data:
Number of mature individuals: 1500-7000 Continuing decline of mature individuals: Yes
Extreme fluctuations: No Population severely fragmented: No
No. of subpopulations: 2-100 Continuing decline in subpopulations: Yes
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No
No. of individuals in largest subpopulation: 1-89

Habitat and Ecology [top]

Habitat and Ecology: It inhabits the margins of clear, undisturbed, fast-flowing and rocky-sided mountain streams and rivers, above 300 m. Adjacent habitat includes tropical montane forest, pine forest or just scrub and scattered trees. Records from Dalton Pass, between August and December, indicate that some birds wander post-breeding.

Systems: Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 3.8
Movement patterns: Not a Migrant

Threats [top]

Major Threat(s): Stream pollution and siltation caused by mining and logging are threats, as is the increasing use of agro-chemicals, all of which negatively affect water quality and prey abundance. A provincial ban on mining was recently rescinded, placing many streams at high risk from toxic pollution in the near future (D. Allen in litt. 2007). As a result, gold mining has become more widespread in recent years, along with the use of mercury in the refining process, which can lead to the pollution of watercourses. In addition to current mining activities, watercourses may also have been polluted by past mining operations (D. Allen in litt. 2012). Within Mt Pulog National Park, cultivation and clearing of forest are common, both of which are likely to cause erosion and siltation in due course. There is also increasing use of fertilisers, herbicides and pesticides by local farmers. Very few suitable, forest-flanked watercourses remain in Mt Iglit-Baco National Park (Mindoro), whilst Mt Data (Luzon) is almost devoid of forest, although some trees were preserved along streams to limit erosion. A vast proportion of Benguet province is now under intense cultivation, although forest areas with poor road access are likely to have survived (D. Allen in litt. 2007).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
It occurs in Balbalasang-Balbalan National Park in Kalinga, Mt Pulog National Park and the Northern Sierra Madre Natural Park on Luzon, and Mt Iglit-Baco National Park on Mindoro. There is also a recent record from the Maria Aurora Memorial National Park, which receives nominal protection.

Conservation Actions Proposed
Conduct comprehensive surveys of suitable mountain streams to clarify its range, distribution, population status and the influence of pollution / siltation on population persistence. Research its ecological requirements and seasonal movements to facilitate conservation planning. Propose further known key sites, including Mts Cetaceo and Polis for establishment as formal protected areas. Promote stricter enforcement of legislation controlling river pollution through logging, agricultural intensification and especially ore mining. Monitor water quality and habitat conditions in areas downstream of mining operations. Campaign for a ban on mining in key areas for this species.

Citation: BirdLife International. 2012. Rhyacornis bicolor. The IUCN Red List of Threatened Species 2012: e.T22710101A39767468. . Downloaded on 25 November 2015.
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