Data Zone
Justification of Red List category
Given its apparent restriction to lowland forest in an area that has suffered extremely rapid destruction of this habitat as a result of conversion to agriculture (especially oil palm plantations) following commercial logging, this species is suspected to have undergone rapid population declines that are likely to continue. It therefore qualifies as Vulnerable.
Population justification
The global population size has not been quantified but is believed to be large given the range and frequency of records in suitable habitat. It is a forest-dependent species and within its range the rate of forest conversion to plantations, primarily oil palm, has been very rapid over the past few decades (Global Forest Watch 2023) and as such the population is inferred to be declining. There are recent records from remaining forested areas across the range, however the extent of suitable habitat is now considerably smaller than three generations ago. Where habitat is secure the species continues to be regularly observed (eBird 2023), though observing the species away from protected areas is becoming much more difficult. In most literature, it is described as uncommon to locally common (Mann 2008, Eaton et al. 2021). Nonetheless, surveys are needed to determine a likely population size given the idiosyncrasies in density at different sites.
Trend justification
Determining the rate of population reduction in this species is difficult owing to considerable uncertainty in its true distribution and clear differences in density between sites/areas. For example, at Danum Valley Conservation Area, the species is common and the most readily-encountered pitta species (eBird 2023), but at other sites (e.g. Ulu Tempurung National Park) it is inexplicably absent, despite ostensibly suitable habitat. The species appears to be dependent on large tracts of low-lying, flat forest (even though, where this is present, it is often found in adjacent degraded habitats and on slopes) which have been the most impacted by deforestation.
In the three generations (12.1 years; Bird et al. 2020) to 2021, forest cover in this species' mapped range was reduced by c.23-25%, depending on the assumptions used (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein). This is considered the minimum rate of reduction given the species' preference for the lowest elevation forests (which have experienced the most rapid deforestation rates) and any impacts of degradation which is not otherwise accounted for. Moreover, at some sites it may have become scarcer even in the absence of habitat loss and degradation. Along the Kinabatangan River, for example, the encounter rate appears to have decreased over the last decade (J. Eaton in litt. 2022, eBird 2023); the cause of this is unknown, but may be explained by delayed fragmentation effects (extinction debt). Consequently, the rate of population reduction is suspected of being 25-35% in the past three generations, although there is substantial uncertainty in this. In the absence of any slowdown in forest loss between 2018 and 2021, this rate of decline is precautionarily suspected to continue in the future three generations, although may ultimately begin to subside as an increasing proportion of the species' range is encompassed by protected areas.
It is endemic to Borneo, where it is recorded throughout; thus Sabah and Sarawak, Malaysia, Brunei and Kalimantan, Indonesia (Mann 2008, eBird 2023). Eaton et al. (2021) did not map the species as occurring in Sarawak, despite historical records from there (Mann 2008). Nonetheless, there are no modern records from the state and it is likely to have always been scarce there; indeed, its densities away from eastern Sabah appear to be low (Mann 2008, eBird 2023).
It is largely restricted to mature, lowland evergreen forest (including regenerating selectively logged forest and old secondary forest), usually extending upslope to only 500 m, rarely to 1,200 m. Its occurrence in selectively logged and secondary forest appears to be dependent on adjacent old-growth forest.
Forest destruction in the Sundaic lowlands of Borneo has been extensive, for timber and conversion to agriculture. In particular the rapid expansion of oil palm has driven the conversion of the majority of remaining lowland forest in the region. Up to 25% of tree cover within the range of the species was lost in the three generations to 2022 (Global Forest Watch 2023). Most of this loss has occurred within the lowlands, where the highest densities of the species would be expected. Moreover, the impact of forest degradation will have added to rates of decline. Associated with the forest loss have been an increase in fire frequency, extent and severity, particularly during strong El Nino events (as in 1998). While the species can use secondary growth and higher elevations, the extent of the threats is such that this species' population is likely to be declining rapidly.
Conservation Actions Underway
The species occurs in a number of protected areas across its range (UNEP-WCMC and IUCN 2023). The degree of protection that designations actually offer varies, however.
17 cm. Medium-sized, brightly coloured, forest-dwelling pitta. Male with glittering blue crown, black cheeks, rich reddish-brown mantle, black wings marked with white and blue tail. White throat, rest of underparts deep violet-blue. Female has rich fulvous-buff crown and upperparts and buffy cheeks to vent. Similar spp. Several sympatric pittas are similar in shape and habits, but all lack the combination of blue crown and reddish mantle. Voice Soft, descending, trisyllabic whistle ppor-wi-iil, sometimes disyllablic.
Text account compilers
Berryman, A.
Contributors
Allinson, T, Benstead, P., Bird, J., Davison, G., Eaton, J., Martin, R., Taylor, J., Tobias, J., Wheatley, H., Yong, D. & van Balen, B.S.
Recommended citation
BirdLife International (2024) Species factsheet: Blue-headed Pitta Hydrornis baudii. Downloaded from
https://datazone.birdlife.org/species/factsheet/blue-headed-pitta-hydrornis-baudii 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.