Banded Pitta Pitta guajana has been split into Malayan Banded Pitta P. irena, Bornean Banded Pitta P. schwaneri and Javan Banded Pitta P. guajana following recommendations put forward by Rheindt and Eaton (2010), who showed the three subspecies to be morphologically, ecologically and probably vocally distinct, with strong and consistent differences in both male and female plumages between each of the taxa, which, given the history of land connections in the region, should probably be regarded as parapatric.
It is proposed that P. irena, P. schwaneri and P. guajana all be listed as Least Concern on the basis that none of them meet the thresholds for Vulnerable under any of the IUCN criteria. These species have large ranges, with Extents of Occurrence (EOOs) estimated in the range 130,000-733,000 km2, hence they do not approach the thresholds for Vulnerable under the range size criterion (EOO less than 20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). They are suspected to be declining due to deforestation and capture for the illegal cage bird trade (Lambert and Woodcock 1996, del Hoyo et al. 2003). However, declines owing to deforestation may be limited by their tolerance of disturbed, degraded and secondary habitats (Lambert and Woodcock 1996, Rheindt and Eaton 2010). Despite the fact that their population trends are suspected to be negative, the declines are not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over 12 years [estimate of three generations]). The population sizes of these species have not been quantified, but they are not believed to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over three generations, or with a specified population structure). Comments are invited on the proposal to list these species as Least Concern and further information is requested, particularly on the estimated population trends and severity of threats for each species.
del Hoyo, J., Elliott, A. and Christie, D. (2003) Handbook of the Birds of the World, vol 8: Broadbills to Tapaculos. Barcelona, Spain: Lynx Edicions.
Lambert, F. and Woodcock, M. (1996) Pittas, broadbills and asities. Robertsbridge, U.K.: Pica Press.
Rheindt, F. E. and Eaton, J. A. (2010) Biological species limits in the Banded Pitta Pitta guajana. Forktail 26: 86-91.
No related posts.