Melodious Babbler Malacopteron palawanense (BirdLife species factsheet), Palawan Blue-flycatcher Cyornis lemprieri (BirdLife species factsheet) and Blue Paradise-flycatcher Terpsiphone cyanescens (BirdLife species factsheet) are all endemic to the western Philippines (Palawan and associated islands), where they inhabit forested areas, and are all listed as Near Threatened.
Melodious Babbler is listed as Near Threatened under criteria A2c+3c+4c; B1ab(iii); C1+2a(i), on the basis that it occupies a very small range, in which habitat is declining, with associated moderately rapid population declines suspected, although suitable habitat is not severely fragmented. The species is listed under the C criteria because its declining population was thought to be moderately small (approaching as few as 10,000 mature individuals); however, there are apparently no estimates available.
Palawan Blue-flycatcher is listed as Near Threatened under criteria A2c+3c+4c; B1ab(ii,iii,v), on the basis that it has a small range, in which suitable habitat is declining but is not severely fragmented, with associated moderately rapid population declines suspected.
Likewise, Blue Paradise-flycatcher is listed as Near Threatened under criteria A2c+3c+4c; B1ab(iii), on the basis that it also occupies a small range, in which suitable habitat is declining but is not severely fragmented, with associated moderately rapid population declines suspected.
However, a recently published study has found that all three species are more tolerant of habitat degradation and fragmentation than was previously thought (Mallari et al. 2011, A. Mallari pers. comm.), bringing into question the validity of their status as Near Threatened. Surveys in Puerto Princesa Subterranean River National Park, Palawan, found these species in cultivated areas (active or recently abandoned farmland), as well as early and advanced secondary growth.
This new information would suggest that their habitats are not approaching severe fragmentation, and that population declines resulting from habitat loss and degradation are unlikely to be moderately rapid (approaching 30% over three generations). Furthermore, simple extrapolation of observed population densities for Melodious Babbler (Mallari et al. 2011) would yield an estimate of well over 50,000 individuals, suggesting that its population does not approach the threshold of 10,000 mature individuals.
It is thus suggested that these species be downlisted to Least Concern, on the basis that they are no longer thought to approach the thresholds for Vulnerable under any of the IUCN criteria.
Comments are invited on the suggested downlisting of these three species and further information would be welcomed.
Reference:
Mallari, N. A. D., Collar, N. J., Lee, D. C., McGowan, P. J. K., Wilkinson, R. and Marsden, S. J. (2011) Population densities of understorey birds across a habitat gradient in Palawan, Philippines: implications for conservation. Oryx 45(2): 234-242.
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