Archived 2014 discussion: Pitcairn Reed-warbler (Acrocephalus vaughani): downlist to Vulnerable?

This discussion was first published as part of the 2013 Red List update, but remains open for comment to enable reassessment in 2014.

BirdLife Species Factsheet for Pitcairn Reed-warbler

Pitcairn Reed-warbler Acrocephalus vaughani is endemic to the tiny volcanic island of Pitcairn. It is currently classified as Endangered because it has a very small population which was believed to be continuing to decline, as a result of habitat degradation and predation by feral cats, which have recovered fairly quickly since control efforts. Although there has never been any detailed census of the species, anecdotal evidence suggests that it has remained relatively common on the island, with no obvious changes in numbers during the past 22 years (M. Brooke in litt. 2012). Predation by Pacific rats and feral cats is likely, but these have been present for many years and do not seem to be causing declines.

It would therefore seem appropriate to reclassify the species as Vulnerable under criterion D1 (having a total population of fewer than 1,000 mature individuals). If there was any evidence that the species was undergoing or predicted to undergo a continuing decline in its range or population it would most likely warrant uplisting to Critically Endangered (under which category it should have been listed previously).

Comments on the likelihood that the species is declining, and therefore whether it should be downlisted or uplisted, are welcomed.

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4 Responses to Archived 2014 discussion: Pitcairn Reed-warbler (Acrocephalus vaughani): downlist to Vulnerable?

  1. Clare Stringer says:

    The statement that the Pitcairn RW population has been stable for 22 years contradicts the previous sentence about Pitcairn RW having increased its population following the attempted eradication of rats and successful feral cat eradication on Pitcairn, and then having suffered a population decline following the resurgence of rats and reintroduction of cats. There has been no published study on Pitcairn RW and we know nothing about population trends, except from anecdotal observations. We suggest that anecdotal information should not be used as the basis of revising species status, especially when provided by irregular visitors to a site rather than local people. The island of Pitcairn is currently subject to several development proposals (e.g. a new harbour) which will mean the destruction of potential habitat for this species. We would suggest that a census of the Pitcairn RW population is an immediate priority, and that regular monitoring to assess population trends should be established before a revision in the status of this species is undertaken. We hope these actions can be pursued by the RSPB in the immediate future, in partnership with the Pitcairn Islands Government’s Environment Department.

  2. Jonathan Hall says:

    There has been no new information on the Pitcairn Reed-Warbler since before it was uplisted to Endangered, so first uplisting it to Endangered and then downlisting it back to Vulnerable all on the same evidence would appear to make a mockery of the rigour of the system. The RSPB currently aspires to facilitate a survey in the middle of 2015. At present, we have no decent population estimate and nothing on trends. Given that the entire island is only 2 miles by 1 mile, the species’ vulnerability is clearly high. Maybe further assessment should just be put on hold until we actually have some evidence?

  3. Joe Taylor says:

    Preliminary proposals

    Based on available information and comments posted above, our preliminary proposal for the 2014 Red List would be to close this discussion and retain Pitcairn Reed-warbler Acrocephalus vaughani as Endangered under criterion C2a(ii).

    There is now a period for further comments until the final deadline of 31 March, after which recommended categorisations will be put forward to IUCN.

    The final Red List categories will be published on the BirdLife and IUCN websites in mid-2014, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  4. Andy Symes says:

    Recommended categorisation to be put forward to IUCN

    Following further review, there has been no change to our preliminary proposal for the 2014 Red List status of this species.

    The final categorisation will be published later in 2014, following further checking of information relevant to the assessment by BirdLife and IUCN.

Comments are closed.