Data Zone
Justification of Red List category
This obscure woodcock has a very small range restricted to the island of Obi and is estimated to have a small population that is inferred to be undergoing a continuing decline due to an accelerating rate of habitat loss, especially in the lowlands where the bulk of the species's population is believed to occur. The occurrence of the species on the island of Bacan is now considered uncertain, with only a single specimen record from more than a century ago. Consequently the population estimate for Obi, based on measured territory size and extent of modelled suitable habitat, is considered to be that for the entire population, 9,500-19,000 mature individuals. Given that occupancy of the entire modelled suitable area is unlikely to be complete, the lower bound is a plausible estimate. With a small population size and a continuing decline, the species is listed as Vulnerable.
Population justification
A MaxEnt species distribution model based on 51 sightings at 11 locations was used to predict that 9,530 territories were likely present on Obi, based on a measured mean territory size of 10.67 hectares (Cottee-Jones et al. 2013). Cottee-Jones et al. (2013) estimated a population size based on a mean of one and two mature individuals per territory (accounting for unoccupied territories) of 9,530 - 19,059 mature individuals. The relationship between number of displaying individuals and population size is currently unknown, so verification of this estimate is desirable. Equally it is very likely that the species is not evenly distributed across this landscape: hence the lower bound is considered the more plausible estimate, especially as the actual number of sites from which the species has been recorded remains very small.
Trend justification
The species has been observed performing aerial display flights in degraded forest, but almost all records are from intact forest areas, and proximity to rivers appears to be a key requirement (Cottee-Jones et al. 2013). Forest cover was a key parameter in the species distribution model, hence the loss of forest cover is considered directly related to the number of territories and mature individuals present. Forest cover loss has been equivalent to 4.7-4.9% over the past three generations (data from Global Forest Watch 2021), but this rate has been increasing. The most recent 5-year annual mean rate of forest cover loss has been 0.5%, compared to a 5-year annual mean of 0.3% between 2001-2005 (data from Global Forest Watch 2021). This increase in rate has also been observed to be directly impacting the species. J. Eaton (in litt. 2020) reported that one site with several displaying birds in early 2016 was bulldozed, with only a single bird located in early 2017. Clearance is being undertaken primarily for conversion of land for agricultural purposes, but there is also significant habitat that has already been lost to mining and extensive degradation through logging.
Scolopax rochussenii is known from the islands of Obi and possibly Bacan, North Maluku, Indonesia, where it was originally known from eight specimens (the most recent collected in 1980) (BirdLife International 2001). It has not been recorded on Bacan apart from a single female specimen (lacking a specific locality) from 1902 (BirdLife International 2001), despite multiple ornithological investigations of the island subsequently (Cottee-Jones et al. 2013).
On Obi, the species was not recorded during surveys in 1991-1992, but was recorded during a two week survey in Obi in 2010 (M. Thibault in litt. 2012) and on 51 occasions at 11 sites during 2012 (out of 20 surveyed, Cottee-Jones et al. 2013). It has been regularly observed since in forested areas close to rivers at a wide range of elevations (Thibault 2010a,b,c, eBird 2021). Previous assumptions about the species being associated with montane forest were incorrect: the species was recorded between 15-1,150 m with a greater (though not statistically significant) number of records at lower elevations particularly in swampy forest or near rivers (Cottee-Jones et al. 2013, J. C. Mittermeier in litt. 2020, J. A. Eaton in litt. 2020).
With the population now considered to be restricted to Obi, the extent of occurrence (EOO) is only 2,100 km2, and a 2 km x 2 km grid over the mapped range (based on the suitability model of Cottee-Jones et al. 2013) gives a maximum area of occurrence (AOO) of 1,928 km2. The true value of the AOO may be considerably smaller than this, as the species was only observed at 11 sites out of 20 during the surveys in 2012 (Cottee-Jones et al. 2013).
Recent records suggest territories are held in lowland forest and the species can tolerate slightly disturbed habitat, with sightings of the species in selectively logged, agroforestry, coconut plantation and agriculturally cleared areas (Thibault et al. 2013, Cottee-Jones et al. 2013). The species is found between 15–1,150 m and has a strong association with streams and rivers (Cottee-Jones et al. 2013). It is assumed to be resident, but may make local elevational movements.
Obi is a small island, with limited forest and no gazetted protected areas. Any deforestation is likely to cause difficulties for the species. The highest densities of the species appear to be in lowland swampy forest, which is reported to be suffering a greater rate of conversion than other forest on the island (J. A. Eaton in litt. 2020). While the species has been observed in degraded forest and edge habitat when displaying, it is considered to require forest alongside rivers and numbers were quickly reduced at one high density site bulldozed in 2016 (J. A. Eaton in litt. 2020). In addition, a large mine has removed a sizable area of previously suitable habitat in the west of the island, and illegal gold mining is suspected to be both destroying further patches of forest and polluting wetland habitat in which the species feeds. Hunting is not considered a current significant threat. Hunters on the island have a very low level of knowledge of the bird and it is not targeted: one hunter who had captured one said he released it because it did not look good to eat (Cottee-Jones et al. 2013). This situation may change quickly with immigration to the island (Cottee-Jones et al. 2013).
Conservation Actions Underway
The species occurs within Pulau Obi National Park, which protects the centre of Obi (UNEP-WCMC 2021). The proposed protected area of Danau Saku may also support the species, though there are no records from around the lake as yet. Given that they are the most mountainous parts of either island, they may not conserve the optimum habitat for the species which appears to be lowland swampy forest (Cottee-Jones et al. 2013, J. A. Eaton in litt. 2020).
Conservation Actions Proposed
Conduct sampling surveys at a large number of sites within the range on Obi, timed to coincide with display flights in order to improve knowledge of distribution and to refine the population estimate. Repeat these at intervals ideally shorter than ten years in order to generate a trend for the population. Use the results of the assessment of distribution and trend to assess the likely severity of recent forest cover loss and habitat degradation on the population. Conduct further surveys for the species on Bacan to establish if the species does currently occur. Support the establishment of protected area at Danau Saku, and also seek to ensure a sizable extent of lowland swamp forest including rivers is protected. There needs to be a management plan devised based on watersheds on Obi to secure ecological services, principally water supply and quality, that can stipulate the retention of riparian vegetation and restrict the proportion of each watershed that may be cleared for agriculture or selectively logged.
32-40 cm. Large, forest-dwelling woodcock. Long, heavy, dark bill. Black upperparts with large contrasting ochre-buff spots and little barring. Underparts fairly uniform orange-buff, with sparse blackish scaling. Black bars on hindneck and between eye and bill. Similar spp. Sulawesi Woodcock S. celebensis is smaller, darker, finely barred rather than spotted and highly unlikely to visit the range of S. rochusseni. Voice 8–11 motifs, given at intervals of 0.04–0.05 seconds, transcribed as "ti’ti’ti’ti’ti’ti’ti’ti’ti" (Thibault et al. 2013).
Text account compilers
Martin, R.
Contributors
Jones, S., Mittermeier, J., Eaton, J. & Wheatley, H.
Recommended citation
BirdLife International (2024) Species factsheet: Moluccan Woodcock Scolopax rochussenii. Downloaded from
https://datazone.birdlife.org/species/factsheet/moluccan-woodcock-scolopax-rochussenii on 22/11/2024.
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 22/11/2024.