Initial deadline for comments: 31 January 2012.
Blue-winged Racquet-tail Prioniturus verticalis is endemic to the Sulu archipelago in the Philippines, where it inhabits forests, including mangroves, and frequents forest edge and degraded forest, but is absent from cultivated areas away from forest. It is currently listed as Endangered under criteria A3b,c,d; A4b,c,d; B1a+b(i,ii,iii,iv,v); C2a(i), on the basis that its declining population numbers fewer than 1,000 mature individuals and is projected to undergo a very rapid decline (50-79%) over the next 10 years or three generations, owing to the on-going threats of forest clearance and hunting within its very small and severely fragmented range.
This species is historically known from a total of six islands; however, there have been no records from Tumindao and Manuk Manka for c.80 years, although there may have been a lack of search effort during this time, and it is regarded as probably extinct on Bongao and Sanga-sanga, although it could persist on Sibutu (D. Allen in litt. 2011). On Tawi-Tawi, ‘very small numbers’ persisted at three sites in the early 1990s, although the situation was said to be deteriorating.
The decline in this species has been driven by rapid and extensive deforestation, with very little, if any, primary forest left on Sibutu and Sanga-sanga. The rapid clearance of primary forest on Tawi-Tawi had rendered remaining lowland patches highly degraded by the mid-1990s, and many of the remnant forest tracts are confined to rugged mountainous areas. Continued logging is likely to be followed by settlement and conversion to agriculture. Hunting is also a major threat to this species, given its tameness and the high rate of gun ownership in its range.
The species appears to be becoming ever scarcer. During a one-week visit to Tawi-Tawi in early 2008, the species did not respond to tape luring (D. Allen in litt. 2008), and it was heard only once during a visit to the island in early 2010, which included seven field days, with visits to Sitio Lambug (Panglima Sugala) and the Bilatan Islands (I. Sarenas in litt. 2010, 2011). However, movement by tourists is restricted owing to security concerns, and the species could be numerous in other parts of the island beyond the small area sampled by visitors (I. Sarenas in litt. 2011). Logging is on-going and hunting pressure on hornbills is increasing, suggesting that other species may be suffering from increased persecution, although a municipal resolution was recently being developed with the hope of putting a stop to the hunting of endemic species (I. Sarenas in litt. 2010).
Local people say that P. verticalis is the least encountered parrot species on Tawi-Tawi (I. Sarenas in litt. 2011). The species seems to be so rare now that there is a real possibility that the declining population now numbers fewer than 250 mature individuals, presumably in one or two subpopulations, depending on whether the species is still extant on Sibutu. If the largest subpopulation numbers no more than 50 individuals or accounts for at least 90% of the total number of mature individuals, the species may qualify for uplisting to Critically Endangered under criterion C2a(ii). Comments are invited on this potential category change and further information would be welcomed.