Data Zone
Justification of Red List category
This species is listed as Vulnerable as it has suffered a rapid population decline over the past 20 years (three generations) due to loss of primary forest cover throughout much of its range. However the true rate of decline may be greater than currently estimated, and evidence of such declines would result in the species being uplisted in the future.
Population justification
The global population size of this species was estimated by Lammertink et al. (2009) to lie somewhere in the broad range of 26,000 to 550,000 mature individuals, a figure derived from an initial remote-sensing based analysis which yielded an estimate of 260,000-550,000, but with an adjusted lower bound (reduced by 90%) to reflect occupancy and the insensitivities of the land cover data used. If these numbers were accurate for 2005 as proposed, then the suspected population decline of 25-49% (best estimate 35–49%) since 2005 (see Population Trend text) yields an adjusted total in 2023 of 13,260–412,500 (best estimate 13,260–357,500). A bespoke internal analysis using land cover data from 2010 (with totals adjusted for forest loss rates since) and an approximate density of 0.5–5 birds/km2 (reflecting a range of densities recorded by Lammertink et al. [2009] and by Kumar and Shahabuddin [2012]) suggests a similar global population of 12,750–63,750. This alternative total is congruent with the scenarios provided by Lammertink et al. (2009) but suggests that their more pessimistic scenarios were likely more accurate. Accordingly, but reflecting the great uncertainty in the population size of this species, the total is set here to 10,000-70,000 mature individuals.
Trend justification
Few direct population data exist this species, although it has evidently declined, probably rapidly, in response to the large-scale clearance and degradation of its forest habitat through most of its range (Lammertink et al. 2009). Remote sensing data suggest that forest cover in this species' range has reduced by c.16–21% over the past three generations (17 years: 2006–2023) (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein).
Alone therefore, remote sensing data indicate a rate of population decline much lower than that proposed here. However, there are several reasons to believe that population declines in this species are (perhaps substantially) more rapid than satellite data alone suggest. In some parts of its range (especially Lao PDR, and perhaps locally in Myanmar and Viet Nam), gun and projectile hunting is thought to have contributed to (at least historic) declines (Timmins et al. in press); this species is vocal and easy to locate, rendering it particularly vulnerable to local areas where there is a high propensity to hunt larger-bodied species. Likely more impacting, however, is the threat of selective logging and habitat degradation that is undetectable to unsensitive remote sensing analyses. This species is dependent on old growth forests with large diameter trees for nesting (Lammertink et al. 2009). Selective logging for these trees—an activity that has increased rapidly with increasing access to even formerly remote forest blocks—is considered to be capable of driving declines possibly greater than outright forest loss. Data to evidence this assumption are few (in part because of its low detectability as a threat), however in Lao PDR, repeat surveys from some sites provides 'strong evidence for serious declines in the species' (Timmins et al. in press, and references therein). This threat is believed to occur across a wide area of this species' range, and is particularly pervasive in lowland dipterocarp deciduous forests of southern Indochina, where densities of this species is high in unaltered habitat (eBird 2023) and large areas of suitable habitat are either not formally protected, or ineffectually so.
The minimum rate of global population decline over the past three generations (17 years: 2005-2023) is set at 25%, representing an optimistic scenario where selective logging is not as serious a threat as suggested by Timmins et al. (in press) and/or it is not as reliant on old growth forests as suspected (Lammertink et al. 2009). The upper bound is set to 49%, representing a scenario where a disproportionate of this species' population occurs in areas most impacted by selective logging. There is high confidence that the true rate of decline lies somewhere between these two scenarios, with a best estimate (given the evidence of localised extirpation/density reduction in Lao PDR: Timmins et al. in press) that a pessimistic scenario (declines of 35-49%) is probably more likely. The same rates of decline are also suspected in the future, with selective logging considered a threat so difficult to control (even in protected areas) that there is a high likelihood that such rapid declines will also occur over the next three generations (17 years: 2023-2040). Whether the rapid declines suspected will ever be reversed is unclear: Timmins et al. (in press) suggest that population recoveries may take decades, if not centuries, to occur.
Mulleripicus pulverulentus is found in South-East Asia, from northern India through the foothills of the Himalaya (including, locally, Nepal and Bhutan) to southern China, Myanmar, Lao PDR, Viet Nam, Cambodia and Thailand, and through Peninsular Malaysia to Sumatra (Indonesia), Borneo, and Palawan, Philippines (del Hoyo et al. 2002, Inskipp et al. 2011, Allen 2020, eBird 2023). It previously bred in Singapore, with the most recent historic observation made in 1949; since, there have been records in 2018 and 2023, but there is no evidence the species has yet recolonised as a breeding bird and here it is still considered a vagrant (Bird Society of Singapore 2023).
Behaviour This resident species breeds between March and June in the west of its range and without a distinct season in South-East Asia (Lammertink 2004; see Kumar and Shahabuddin 2012). Clutch size is two to four eggs. Nest-hole excavation, incubation and chick-rearing are conducted by both sexes, with helpers at some nests. It forages in noisy groups of three to six individuals and sometimes more (Lammertink 2004). Groups occupy large territories. It is not a migrant, however, in areas of its distribution that show a marked seasonality (e.g. Himalayan foothills) the home range appears to expand locally during winters (Kumar et al. 2011).
Habitat It occupies primary semi-open moist deciduous and tropical evergreen old growth, lower elevation forests, as well as adjacent secondary forest and clearings with scattered tall trees. It prefers dipterocarp (e.g. Shorea robusta in Himalayan foothills [R. Kumar in litt. 2016]) and teak forests in certain areas, as well as swamp-forest and tall mangroves. It is most frequent in lowlands and lower hills below 600 m, but does occur up to 1,100 m in the Himalaya and occasionally up to 2,000 m.
Diet Foraging groups search and exploit nests of social insects (ants, termites, and stingless bees), often in trunks and branches of old live trees. Birds may also take small fruit (Lammertink 2004).
The chief cause of rapid declines in this species has been the loss and degradation of forest within its range (Lammertink et al. 2009). The scale and cause of this varies in different countries, but almost nowhere in its range is totally removed from the overarching threat. In the Greater Sundas (especially lowland Borneo and Sumatra), the principal driver of forest cover loss has been the industrial-scale removal of forest, initially for timber extraction, but motivated in part or in whole by the replacement of these forested areas with large-scale plantations, especially oil-palm and rubber. More locally, this is compounded by localised shifting agriculture and timber extraction, the latter especially targeting larger, hollow-bearing trees needed by this species. The damage caused in Indochina has ostensibly been lesser, with rates of overall forest cover loss incomparable to those in the Greater Sundas (Global Forest Watch 2023); however, here selective logging and clearance for agriculture has been pervasive, rendering remaining stands of forest among the least intact in Asia (Grantham et al. 2020). Concerningly, this has been most acute in the deciduous dipterocarp forests in the lowlands favoured by this species, especially in Cambodia and southern Lao PDR, and in both countries rapid declines are suspected to have occurred over the last 20 years, and even by then the species' population size was only a small fraction of its historic baseline. In Lao PDR, and possibly also Myanmar and Viet Nam, gun and projectile hunting is thought to have contributed to (at least historic) declines (M. Lammertink in litt. 2012, Timmins et al. in press). Moreover, in Lao PDR, hydroelectric power plants have flooded considerable areas of lowland forest (Soukhaphon et al. 2021). In Myanmar, Bangladesh and parts of India, selective logging, even in nominally protected areas, continues and presumably is driving (at least slow) population declines as elsewhere in the species' range, although data are sparse. In the Himalayan foothills, clearance for sal Shorea robusta plantations continues and is likely driving slow declines (Kumar and Shahabuddin 2012), although these are not typically in global strongholds.
Conservation Actions Underway
No current action is known for this species, although it does occur in many protected areas (UNEP-WCMC and IUCN 2023).
Text account compilers
Berryman, A.
Contributors
Baral, H.S., Inskipp, C., Kumar, R., Lammertink, M., Styring, A. & Timmins, R.J.
Recommended citation
BirdLife International (2024) Species factsheet: Great Slaty Woodpecker Mulleripicus pulverulentus. Downloaded from
https://datazone.birdlife.org/species/factsheet/great-slaty-woodpecker-mulleripicus-pulverulentus 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.