This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for non-passerines
Lynx Edicions and BirdLife International will soon publish the HBW-BirdLife Illustrated Checklist of the Birds of the World, building off the Handbook of the Birds of the World series, and BirdLife’s annually updated taxonomic checklist.
The new Checklist will be based on the application of criteria for recognising species limits described by Tobias et al. (2010). Full details of the specific scores and the basis of these for each new taxonomic revision will be provided in the Checklist.
Following publication, an open and transparent mechanism will be established to allow people to comment on the taxonomic revisions or suggest new ones, and provide new information of relevance in order to inform regular updates. We are also actively seeking input via a discussion topic here regarding some potential taxonomic revisions that currently lack sufficient information.
The new Checklist will form the taxonomic basis of BirdLife’s assessments of the status of the world’s birds for the IUCN Red List. The taxonomic changes that will appear in volume 1 of the checklist (for non-passerines) will begin to be incorporated into the 2014 Red List update, with the remainder, and those for passerines (which will appear in volume 2 of the checklist), to be incorporated into subsequent Red List updates.
Preliminary Red List assessments have been carried out for the newly split or lumped taxa. We are now requesting comments and feedback on these preliminary assessments.
Sulawesi Kingfisher Ceyx fallax is being split into C. fallax and C. sangirensis, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, C. fallax (BirdLife species factsheet) was listed as Near Threatened under criteria C1;C2a(i), on the basis that it probably had a moderately small population (approaching as few as 10,000 mature individuals), as it is scarce and patchily distributed within its restricted range, and was likely to be in continuing decline owing to on-going habitat loss and degradation.
C. sangirensis is known from the island of Sangihe (Fry and Fry 1999, del Hoyo et al. 2001), and is listed in some sources as occurring on the Talaud Islands, Indonesia (e.g. del Hoyo et al. 2001). It is not clear whether it has ever been recorded on or likely to occur on Siau or any other nearby islands. C. sangirensis is presumed to rely heavily on lowland primary forest (Fry and Fry 1999, del Hoyo et al. 2001), but may tolerate some habitat degradation and fragmentation.
Surveys on Sangihe in 1998-1999 did not yield any records of this taxon, leading to a suspicion that it could be extinct there (Riley 2002). On Sangihe, lowland primary forest is thought to have been completely or almost completely removed, although the species could persist in inaccessible forested gullies on the margin of its upper elevation limit, and it has been noted that other species of this genus can be difficult to find (J. Eaton in litt. 2013, F. Lambert in litt. 2013).
The status of this species on Talaud seems uncertain. Riley (1997) did not record the species during fieldwork in 1995, and suggested that it was one of a suite of species that had suffered population reductions as a result of habitat loss. The only source cited by Riley (1997) for records of this species on Talaud is Meyer (1879 per Meyer and Wiglesworth 1898 in Riley 1997), who reported it to be quite common, but soon after this Blasius (1888 in Riley 1997) stated that other collectors did not find it. This raises the question of whether Meyer’s identifications or notes could have been erroneous, and whether the species has ever been reliably recorded on the Talaud Islands.
Unless confirmed records come to light, under the precautionary principle it could be assumed that this newly-defined species is not extant on the Talaud Islands (either extirpated or having never occurred there). It appears to be very rare or extirpated on Sangihe. On this basis, C. sangirensis is likely to qualify as Critically Endangered under criterion C2a(ii), as any remaining extant population is likely to be extremely small, probably numbering far fewer than 250 mature individuals, precautionarily assumed to form a single subpopulation, which is inferred to be in continuing decline owing to on-going habitat loss and degradation. Given the apparent dearth of recent records, the species could be listed as ‘Critically Endangered (Possibly Extinct)’.
C. fallax (as defined following the taxonomic change) is patchily distributed across mainland Sulawesi, as well as on Lembeh Island, where it occupies primary forest, and sometimes selectively logged and tall secondary forest, in the lowlands and hills, from the coast to 1,000 m, but mostly below 600 m (Fry and Fry 1999, del Hoyo et al. 2001). It is suggested that the species be listed as Near Threatened under criteria C1+2a(ii), on the basis that it probably has a moderately small population (approaching as few as 10,000 mature individuals, all in one subpopulation), which is inferred to be in continuing decline owing to on-going and extensive habitat destruction and degradation.
Comments on these suggested categories and further information, particularly on the status of C. sangirensis, would be welcomed.
del Hoyo, J., Elliott, A. and Sargatal, J. (2001) Handbook of the birds of the world, Vol 6: Mousebirds to Hornbills. Barcelona, Spain: Lynx Edicions.
Fry, C. H. and Fry, K. (1999) Kingfishers, bee-eaters & rollers. Princeton, NJ: Princeton University Press.
Riley, J. (1997) The birds of Sangihe and Talaud, North Sulawesi. Kukila 9: 3–36.
Riley, J. (2002) Population sizes and the status of endemic and restricted-range bird species on Sangihe Island, Indonesia. Bird Conservation International 12: 53–78.
Tobias, J. A., Seddon, N., Spottiswoode, C. N., Pilgrim, J. D., Fishpool, L. D. C. and Collar, N. J. (2010) Quantitative criteria for species delimitation. Ibis 152: 724–746.