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.
Red-headed Fody Foudia eminentissima is being split into F. eminentissima, F. aldabrana and F. consobrina, following the application of criteria set out by Tobias et al. (2010).
Prior to this taxonomic change, F. eminentissima (http://www.birdlife.org/datazone/species/factsheet/22719138) was listed as Least Concern, on the basis that although it was range restricted to the islands of the Comoros, Mayotte (to France) and Aldabra Atoll, Seychelles, it was not thought to approach the threshold for Vulnerable under any criteria.
F. eminentissima (as defined now after the taxonomic change) is found on Mayotte (France) and the islands of Mohéli and Anjouan in the Comoros (see Craig 2016). It is found in forested areas, but on Mayotte, it is not in evergreen forest (Craig 2016). On Mayotte, the population may number 5,000-10,000 individuals (Rocamora 2004), roughly equivalent to 3,333-6,667 mature individuals. With a density of <27 males per km2 on Mohéli, and lower densities on Anjouan (Safford and Louette 2013), the population is suspected to fall in the range of 10,000-19,999 mature individuals. The population is inferred to be declining due to nest predation by species such as Black Rat (Rattus rattus), Brown Lemur (Eulemur fulvus) and Mongoose Lemur (E. mongoz). Additionally, cyclones, mangrove destruction, disease, poisoning and competition with House Sparrows (Passer domesticus) may be an issue for this species, particularly on Mayotte (Safford and Louette 2013). We request further information regarding the magnitude of possible declines on Mayotte, and whether similar declines may be occurring on the other islands.
F. aldabrana is found only on Aldabra Atoll, Seychelles, in scrub, coconut (Cocos nucifera) groves andCasuarina woodland, as there is no forest found there (Craig 2016). Its population is estimated at between 2,000 and 6,000 mature individuals (Rocamora and Skerrett 2001), but nest predators act across the island, and nesting success may be very low; with 48% of nestlings and 81% of eggs taken by predators such as Pied Crows (Corcus albus) and Black Rats (Rattus rattus) (Safford 2013). There is currently no evidence that this predation is causing the population to decline, but there is the potential for this to become an issue in the future, and as this species has such a limited range this threat could affect the whole population. It is not however thought that any threat would be likely to cause the species to become Critically Endangered or Extinct within a short space of time. Therefore, it is proposed that this species be listed as Near Threatened, approaching the thresholds for listing as Vulnerable under criterion D2, in common with fellow Aldabran endemic the Aldabra Drongo.
F. consobrina is found only in forested areas on the island of Grand Comoro of the Comoros (Craig 2016). Prior to this taxonomic change, the population on Grand Comoro was reported to be the most common of F. eminentissima, but there are no density or population estimates currently known. Nests may be predated by Black Rats (Rattus rattus), which are a threat throughout the Comoros (Safford 2013), but there is no evidence currently to suggest that this may be causing the population to decline. This is currently not thought to be a sufficient enough possible future threat to warrant this species to be listed as Vulnerable, and it is unlikely to approach the threshold for Vulnerable under other criteria. Hence it is proposed that this species be listed as Least Concern.
Comments are invited on these proposed categories and further information would be welcomed.
Craig, A. (2016). Red-headed Fody (Foudia eminentissima). 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/60998 on 26 August 2016).
Rocamora, G. and Skerrett, A. (2001) Seychelles. Pp. 751-768 in Fishpool, L. D. C. and Evans, M. I. (eds) Important Bird Areas of Africa and associated islands. Cambridge, UK: BirdLife International.
Safford, R. J. (2013) Aldabra Fody Foudia aldabrana. Pp. 889-892 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. and Louette, M. (2013) Comoro Fody Foudia eminentissima. Pp. 886-888 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.