Green Racquet-tail (Prioniturus luconensis): uplist to Endangered?

The initial deadline for comments on this topic is 28 April 2014, and therefore later than for most other topics currently under discussion.

Green Racquet-tail Prioniturus luconensis (BirdLife species factsheet) is currently classified as Vulnerable as it is suspected to be undergoing a continuing rapid decline owing to extensive deforestation of its lowland forest habitat, with a total population of fewer than 10,000 mature individuals and all subpopulations comprising fewer than 1,000 mature individuals.

Prioniturus luconensis is endemic to the Philippines, where it is known from Luzon and Marinduque. It occurs in the canopy of primary forest and edge, occasionally foraging in open cultivated areas, in lowlands and foothills e.g. at 300-700 m in Sierra Madre (del Hoyo et al. 1997). Formerly widespread and locally abundant, it has declined rapidly.

Trapping for the cage-bird trade is a significant problem, and local extinctions as a direct result of forest loss are very likely. In 1988, forest cover was just 3% on Marinduque and 24% on Luzon. Forest cover in the Sierra Madre mountains has declined by 83% since the 1930s. Most remaining areas are under logging concession and may suffer further from major road-building plans. A road development near Subic Bay has increased the incidence of illegal logging and felling is rife at Maria Aurora Memorial Natural Park. Habitat modification may have accentuated interspecific competition, with the species having been replaced by Blue-crowned Racquet-tail P. discurus in Quezon National Park.

At two sites with records since 1980, Quezon National Park and Angat Dam, it now appears to be extinct, having been common at the former in the 1980s. There are no recent records from Marinduque, where it may already be extinct. It is believed extirpated from Bataan Natural Park (where the area of old growth forest in Bataan decreased by 65% between 1987/1993 and 2002), and apparently scarcer than in the early 1990s even at its remaining stronghold at Subic Bay Forest Reserve (A. Jensen in litt. 2013). It has been recorded at only seven out of 29 historic sites in the last 10 years; although possibly a function of poor coverage, it may more likely represent a genuine range contraction (Española et al. 2013).

Distance sampling along nearly 500 km of line transects at 14 sites across Luzon in 2009-2010, then multiplying site-specific density estimates by reserve area, resulted in estimates of 246 individuals (42-1,434, 95% CI) in Northern Sierra Madre Natural Park, and 174 (80-380, 95% CI) in Subic Bay Forest Reserve / Bataan Natural Park (Española et al. 2013). The data therefore suggest that there may be fewer than 250 mature individuals in each of the two main remaining subpopulations. It appears the Green Racquet-tail might now only occur in two areas of Luzon and that Subic Bay might be the only one with any protection. (R. Hutchison in litt. 2013). Even here, there are potential threats to the habitat: in 2013 the Philippine military had reportedly revived plans to build new air and naval bases at Subic Bay and to reopen the base to United States forces.

If the total population is estimated to number fewer than 2,500 mature individuals, the largest subpopulation contains 51-250 mature individuals, and the species is undergoing a continuing decline, then it would be eligible for uplisting to Endangered under criterion C2a(i).

Additional information and comments on this proposal are welcomed.

References

del Hoyo, J.; Elliott, A.; Sargatal, J. 1997. Handbook of the Birds of the World, vol. 4: Sandgrouse to Cuckoos. Lynx Edicions, Barcelona, Spain.

Española, C. P., Collar, N. J. and Marsden, S. J. (2013), Are populations of large-bodied avian frugivores on Luzon, Philippines, facing imminent collapse? Animal Conservation, 16: 467–479. doi: 10.1111/acv.12018

Juniper, T.; Parr, M. 1998. Parrots: a guide to the parrots of the world. Pica Press, Robertsbridge, UK.

Related posts:

  1. Archived 2011-2012 topics: Blue-winged Racquet-tail (Prioniturus verticalis): uplist to Critically Endangered?
  2. Blue-crowned Racquet-tail (Prioniturus discurus) is being split: list P. mindorensis as Vulnerable?
  3. Archived 2011-2012 topics: Taxonomic change in the genus Cissa: list Javan Green Magpie (C. thalassina) as Critically Endangered and Bornean Green Magpie (C. jefferyi) as Least Concern?
  4. Whiskered Pitta (Pitta kochi): downlist to Near Threatened?
  5. Archived 2012-2013 topics: Cheer Pheasant (Catreus wallichi): uplist to Endangered?
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2 Responses to Green Racquet-tail (Prioniturus luconensis): uplist to Endangered?

  1. Andy Symes says:

    Preliminary proposals

    Based on available information, our preliminary proposal for the 2014 Red List would be to treat:

    Prioniturus luconensis as Endangered under criterion C2a(i)

    There is now a period for further comments until the final deadline of 16 May, after which the recommended categorisation will be put forward to IUCN.

    The final Red List categories will be published on the BirdLife and IUCN websites in mid-2014, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  2. Joe Taylor says:

    Recommended categorisations to be put forward to IUCN

    Following further review, there has been no change to our preliminary proposal for the 2014 Red List status of this species.

    The final categorisations will be published in mid-2014, following further checking of information relevant to the assessments by BirdLife and IUCN.

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