Alcedo argentata


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Alcedo argentata
Species Authority: Tweeddale, 1877
Common Name/s:
English Silvery Kingfisher

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2c+3c+4c ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor/s: BirdLife International
Reviewer/s: Butchart, S. & Symes, A.
Contributor/s: Ibanez, J.
Facilitator/s: Benstead, P., Bird, J., Davidson, P., Lowen, J., Peet, N., Taylor, J.
This species qualifies as Vulnerable because its population is suspected to be undergoing a rapid decline as a result of the loss and decline in quality of its forested lowland stream habitats.

Geographic Range [top]

Range Description: Alcedo argentata is endemic to the Philippines, where its two distinct populations occur on Samar, Leyte and Bohol (A. a. flumenicola), and Dinagat, Siargao, Mindanao and Basilan (A. a. argentata) (Collar et al. 1999). Formerly widespread and locally common, a comparison of pre-1970 and more recent records indicate a decline throughout its range. Since 1980, there have been documented observations from only c.10 sites confined to east Mindanao, Bohol and Leyte, although there are also recent sightings from the Zamboanga Peninsula, particularly within the Lituban-Quipit Watershed IBA. It is shy and inconspicuous and very likely under-recorded. Nevertheless, remaining areas of lowland forest with clear streams are very limited.

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.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: It appears to be reliant upon forested streams below 1,000 m (with one record from 1,120-1,350 m). It will tolerate secondary and selectively logged forest and even streamside vegetation within coconut plantations, close to forest edge, but terminalia and sago are the principal forest types where the highest densities were recorded during mist-netting in 2002-2003 (J. Ibanez in litt. 2007). It breeds in riverside banks and is apparently sedentary.

Systems: Terrestrial; Freshwater

Threats [top]

Major Threat(s): Extensive lowland deforestation throughout its range is the chief threat. Only 4% forest cover is estimated to remain on Bohol. Most remaining lowland forest is leased to logging concessions or mining applications. Watercourses with high siltation loads, resulting from deforestation, appear not to hold the species, and riverine pollution is likely to have a similar impact. Tree-cutting, agricultural expansion, including pesticide (specifically Carbofuran) contamination from commercial growing of banana, and soil erosion are all threats to Rajah Sikatuna National Park (Bohol) and forest at Bislig (Mindanao) is being cleared under concession and re-planted with exotic trees for paper production. Both are key sites for the species. Conversion of terminalia forest into rice fields and oil palm plantation is driving habitat loss elsewhere.

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
There are post-1990 records from two protected areas, Rajah Sikatuna National Park, Bohol and Agusan Marsh, Mindanao. There are pre-1980 records from two further protected areas, Siargao Island and Mt Apo Natural Park, Mindanao, and also northern Dinagat Island, which is a priority site for conservation funding. There were recent sightings at Lituban Quipit Watershed and there is a pending DENR proposal to have this IBA declared as a national protected area (J. Ibanez in litt. 2007). Meanwhile, 627,631 ha of lowland forest watersheds, which are likely habitats for the species, were declared through Presidential Proclamation as protected watersheds (J. Ibanez in litt. 2007). While populations in Pasonanca (10,560 ha; Zamboanga City) and Malagos Watersheds (235 ha, Davao City) are well protected by armed guards patrolling the watershed, doubts remain over how well these sites are managed and protected (J. Ibanez in litt. 2007). Current laws protecting riverine habitats are weak and require revision.

Conservation Actions Proposed
Conduct further surveys to clarify its current distribution and population status. Investigate factors affecting river pollution and determine its dependency on high-quality watercourses. Establish further protected areas at other key lowland sites (e.g. Mt Cabalantian/Capoto-an on Samar, Mt Lobi on Leyte, and Mts Dapiak, Sugarloaf, Piapayungan, Diwata and Mayo on Mindanao). Encourage the legal and practical protection of riparian habitats.

Citation: BirdLife International 2012. Alcedo argentata. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 23 April 2014.
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