Archived 2016 topics: Comoro Bulbul (Hypsipetes parvirostris) is being split: list H. parvirostris as Vulnerable and H. moheliensis as Endangered?

This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for passerines

Lynx Edicions and BirdLife International will soon publish the second volume of 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 2 of the checklist (for passerines) will begin to be incorporated into the 2016 Red List update, with the remainder 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.

Comoro Bulbul Hypsipetes parvirostris is being split into H. parvirostris and H. moheliensis, following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, H. parvirostris was listed as Least Concern on the basis that it did not approach the threshold for listing as Vulnerable under any criterion. H. parvirostris (as now defined following the taxonomic change) is found in forest, as well as clearings and degraded areas on Grand Comore, Comoros (Louette and Herremans 1985). While it is displaced at lower altitudes by Madagascar Bulbul, H. madagascariensis, it is reasonably common (with encounter rates of 25 birds/hr [Safford 2013a]), although less common above 1,000m (Louette 2004). It is restricted to an Extent of Occurrence of c.1,300 km2, and its habitat continues to be threatened by destruction for agriculture (Fishpool and Tobias 2016). Given its restricted range, this species is not thought to number more than 10,000 mature individuals, and as it is restricted to one subpopulation, this species likely qualifies as Vulnerable under criterion C2a(ii).

H. moheliensis is found in forest, as well as clearings and degraded areas on Mohéli, Comoros (Louette and Herremans 1985), with an Extent of Occurrence of only c.340 km2. Despite being relatively common in its remaining habitat, its population has been estimated at <1,000 pairs (Safford 2013b), which is inferred to be declining as a result of habitat clearance (Safford 2013b). Therefore, this species may qualify as Endangered under criteria B1ab(ii,iii,v); C2a(ii).

Comments are invited on these proposed listings, and any further information would be welcomed.

References:

Fishpool, L. & Tobias, J. 2016. Comoro Black Bulbul (Hypsipetes parvirostris). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/58045 on 14 September 2016).

Louette, M. 2004. Oiseaux. Pp. 91-196 in Louette, M., Meirte, D. & Jocqué, R. eds. (2004). La Faune Terrestre de l’Archipel des Comores. Studies in Afrotropical Zoology 293. Musée Royal de l’Afrique Centrale, Tervuren, Belgium.

Louette, M. and Herremans M. 1985. Taxonomy and evolution of the bulbuls (Hypsipetes) on the Comoro Islands. Pp. 407-423 in Schuchmann, K.-L. (ed.) Proceedings of the International Symposium on African Vertebrates. Bonn, Germany: Museum Alexander König.

Safford, R. J. 2013a. Grand Comore Bulbul Hypsipetes parvirostris. Pp. 677-678 in Safford, R. J. and Hawkins, A. F. A. (eds) The Birds of Africa. Vol VIII: The Malagasy Region. Christopher Helm, London.

Safford, R. J. 2013b. Mohéli Bulbul Hypsipetes moheliensis. Pp. 676-677 in Safford, R. J. and Hawkins, A. F. A. (eds) The Birds of Africa. Vol VIII: The Malagasy Region. Christopher Helm, London.

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.

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One Response to Archived 2016 topics: Comoro Bulbul (Hypsipetes parvirostris) is being split: list H. parvirostris as Vulnerable and H. moheliensis as Endangered?

  1. James Westrip (BirdLife) says:

    Based on available information, our preliminary proposal for the 2016 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.

    There is now a period for further comments until the final deadline of 28 October, after which the recommended categorisations will be put forward to IUCN.

    Please note that we will then only post final recommended categorisations on forum discussions where these differ from those in the initial proposal.

    The final 2016 Red List categories will be published on the BirdLife and IUCN websites in early December, following further checking of information relevant to the assessments by both BirdLife and IUCN.

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