NT
Slender-billed Flufftail Sarothrura watersi



Justification

Justification of Red List category

This species is suspected to have a small or very small population that is declining due to the ongoing loss and degradation of its wetland habitats. It is therefore classified as Near Threatened. Urgent survey is required to assess the plausible bounds of the population size, which may lead to the species being reassessed as threatened in the future.

Population justification
There is very little data on the species occurrence from which a population estimate can be derived. Previously, based on the likely small area of remaining habitat (P.B. Taylor in litt. 1999) a provisional population size was given as most likely to fall between 250-999 mature individuals. However, no surveys to generate even rough abundance have been carried out and while it is plausible that the population size is small or very small, this can only be suspected from the available information. The abundance of the species at individual sites is unknown largely due to the secretive nature of the species, but also a lack of targeted survey effort. In addition, there is the potential for suitable habitat to be present at a number of sites additional to those that do have records (Safford and Hawkins 2013). What is currently known is that records come from three areas that are widely separated but all lie within a narrow elevational band in the zone of eastern slope rainforest, which is now highly fragmented itself (Safford and Hawkins 2013). The areas with records are also sites regularly visited by birdwatching groups: systematic or randomised searches of similar habitat in between has not yet taken place. The current, suspected small or very small population size is retained, but there is potential for the true population to be somewhat larger given the limited survey effort to date.

Trend justification
This species's population is inferred to be declining due to ongoing habitat loss owing to transformation of its aquatic habitats by agricultural activities (Kull 2012) and from reports of a recent sudden drop in abundance at a site where the species was previously commonly observed (L.-A. Rene de Roland in litt. 2022). Kull (2012) estimated that between 1950-1994, 60% of wetlands were lost, roughly equating to a loss rate of 19% over 10 years. Wetlands are being degraded through conversion to rice paddies, and while there is some evidence that this species can utilise these habitats (Taylor and van Perlo 1998) almost all records come from wetlands in the vicinity of forest. Assuming that the rate of loss is continuing at the same rate, and that the population declines at a similar rate, then the rate of decline is suspected to fall into the band of 10-19%. Wetland degradation is linked to the expanding population, hence it is likely to continue.

Distribution and population

Sarothrura watersi has been recorded reliably from well-separated areas in eastern Madagascar. If 1970-1971 records from the Antananarivo district are discounted as erroneous, the remaining sites are near Analamazaotra in 1928, near Andapa in 1930, Torotorofotsy Marsh since 1997, several sightings at Anjozorobe (including photograph in 2009 [Safford 2013]), Ranomafana/Vohiparara since 1988, and in Andringitra National Park, as well as between Andringitra and Ranomafana - corresponding to specimens from "south-east Betsileo" in 1875 (Safford 2013). All sites are in, or adjacent to, mid-altitude rainforest. Its marshland habitat is widely but very patchily distributed (Wilmé and Langrand 1990, ZICOMA 1999) and it may yet occur at other sites, having been overlooked due to its extremely secretive behaviour (Morris and Hawkins 1998). Nevertheless, very little suitable habitat is likely to remain (P.B. Taylor in litt. 1999), and its total population may number considerably less than 1,000 individuals (Taylor and van Perlo 1998).

Ecology

Behaviour The species is presumed to be sedentary in the absence of any evidence of movements (del Hoyo et al. 1996, Taylor and van Perlo 1998). It is incredibly difficult to see (Langrand 1990), but has a fairly loud and distinctive call, given most frequently between October and February. It may thus breed during the rainy season, but its breeding behaviour is otherwise unknown (Langrand 1990). Habitat This is an aquatic species which is largely confined to permanent, montane marshland which is shallowly flooded, at least seasonally, and dominated by dense, short grasses, with scattered clumps of thin-stemmed sedges and rushes (Cyperus, Schoenoplectus) (P.B. Taylor in litt. 1999). It prefers wetlands with adjacent dense, grassy terrain or even rice paddies, near rainforest at altitudes of 950-1,800m (Taylor and van Perlo 1998). It is possible that it may also occur in overgrown, weedy, disused agricultural land and the scrubby edges of marshes (Taylor and van Perlo 1998). Diet Its diet is unknown (Langrand 1990, del Hoyo et al. 1996, Taylor and van Perlo 1998). Breeding site Its nest, nest site and eggs are unknown (Langrand 1990, del Hoyo et al. 1996, Taylor and van Perlo 1998).

Threats

Most grass-dominated marshes on the eastern plateau of Madagascar are heavily used and exploited, especially for cultivating rice, the staple diet of the rapidly increasing human population (Langrand and Goodman 1995, Kull 2012). Climate change may pose a threat in the future due to its direct effect on the species's habitat, and indirectly via its effects on human populations (Segan et al. 2015). More recently, the Ranomafana National Park appears to be under threat from habitat degradation due to illegal gold mining (Cabeza et al. 2019).

Conservation actions

Conservation Actions Underway
Ranomafana has been a national park since 1987, but there is no protection specifically for wetlands in eastern Madagascar (Stattersfield et al. 1998). The Malagasy government has ratified the Ramsar Convention, which came into force for the country in 1999. Ramsar site status has benefited the conservation of at least one site where the species occurs, Torotorofotsy Marsh, and the convention could be of additional importance to the species if it is found in the watershed of Lake Alaotra (O. Langrand in litt. 2007).

Conservation Actions Proposed
Survey the distribution and population at all known and possible sites of occurrence (Langrand and Wilmé 1993). Evaluate sites suitable for protection (Taylor and van Perlo 1998). Assess the feasibility of conducting research into the species's ecology and life history. Enforce the protection of the Ranomafana national park against illegal gold mining. 

Identification

14-17 cm. Tiny rail, with slim body and bill. Males are rufous, darker on mantle and wings and paler on throat and central belly. Females are greyish-brown, slightly barred darker on rear flanks and on tail, and paler on belly. Similar spp. Male distinguished from Madagascar Flufftail S. insularis by lack of black on upperparts and belly, female by lack of streaking on back and underparts. From all other rails by tiny size and rufous coloration. Voice Call is a rhythmic, repeated chong-ga-chonk and variants. Hints Call is only realistic way of locating species.

Acknowledgements

Text account compilers
Clark, J., Rotton, H.

Contributors
Benstead, P., Ekstrom, J., Evans, M., Hawkins, F., Khwaja, N., Langrand, O., Réné De Roland, L.A., Safford, R., Shutes, S., Starkey, M., Symes, A., Taylor, P.B., Taylor, J. & Westrip, J.R.S.


Recommended citation
BirdLife International (2024) Species factsheet: Slender-billed Flufftail Sarothrura watersi. Downloaded from https://datazone.birdlife.org/species/factsheet/slender-billed-flufftail-sarothrura-watersi on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.