Archived 2016 topics: New Zealand Fernbird (Bowdleria punctata) is being moved to genus Poodytes and is being split: list P. punctatus as Least Concern and P. caudatus as Near Threatened?

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 theHBW-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.

New Zealand Fernbird (Bowdleria punctata) is being moved to genus Poodytes and is being split into P. punctatus and P. caudatus following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, New Zealand fernbird (http://www.birdlife.org/datazone/species/factsheet/22715504) was listed as Least Concern on the basis that it did not approach the threshold for Vulnerable under any criteria. Poodytes punctatus (as now defined following the taxonomic change) is found throughout the North and South and Stewart Islands of New Zealand as well as on some smaller offshore islands. It is locally common throughout its range, and is not thought to approach the thresholds for Vulnerable, although it is considered to be declining across its range (Miskelly 2013) and its status should be kept under review. It is proposed that P. punctatus be listed as Least Concern.

P. caudatus (as now defined following the taxonomic change) is found only on the Snares Islands with a total Area of Occupancy of c.3.5 km2. The population has been estimated at c1,500 pairs, and densities appear to have remained fairly stable since the late 1940s (Miskelly et al. 2001). Given the restricted area of occupancy and number of locations, it is suggested that this newly split species should be listed as Near Threatened under Criterion D2 on the basis that an incursion of non-native mammalian predators to the Snares could quickly lead to this species becoming Critically Endangered or Extinct.

Comments are invited on these proposed categories and further information would be welcomed.

 

References: 

McLean, I.G.; Miskelly, C.M. 1988. Breeding biology of the black tit (Petroica macrocephala dannefaerdi) on the Snares Islands, New Zealand. New Zealand natural sciences 15: 51-59.

Miskelly, C.M. 2013. Fernbird. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz

Miskelly, C.M.; Sagar, EM.; Tennyson, A.J.D; Scofield, R.P. 2001. Birds of the Snares Islands, New Zealand. Notornis 48(1): 1-40.

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: New Zealand Fernbird (Bowdleria punctata) is being moved to genus Poodytes and is being split: list P. punctatus as Least Concern and P. caudatus as Near Threatened?

  1. James Westrip (BirdLife) says:

    Based on available information, our preliminary proposal for the 2016 Red List would be to list:

    P. punctatus as Least Concern.

    P. caudatus as Vulnerable under criterion D2 on the basis that it is likely the species occurs at less than 5 locations* and so would meet, rather than approach the threshold for Vulnerable under this criterion.

    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 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.

    *Note that the term ‘location’ defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the taxon present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a taxon is affected by more than one threatening event, location should be defined by considering the most serious plausible threat (IUCN 2001, 2012).

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