Archived 2012-2013 topics: Superb Pitta (Pitta superba): uplist to Endangered?

BirdLife species factsheet for Superb Pitta Superb Pitta Pitta superba is restricted to Manus in the Admiralty Islands of Papua New Guinea. It is currently listed as Vulnerable under criterion D1 because its population is estimated to number fewer than 1,000 mature individuals based on an assessment of known records, descriptions of abundance and range size, but its population trend was unknown. It has an enigmatically patchy distribution and probably occurs at low population densities. Four pairs have been found in recent years around Rossun village, whilst in 2002 three birds were heard within a small area of forest 10 km inland from the north-western coast (Williams in litt. 2002), but by 2007 only one bird could be located (G. Dutson in litt. 2007). Whilst most of Manus remains unsurveyed and this bird may be largely silent and thus overlooked, it is absent from several seemingly suitable areas (Dutson and Newman 1991, D. Gibbs in litt. 1994, G. Dutson pers. obs. 1997, A. Mack in litt. 2012). The ‘known’ population is apparently just a few pairs that bird watching groups find reliably around Rossun village and thus, the population across the island may be wrongly assumed to be significant (A. Mack in litt. 2012). During eight visits to Manus between 2002 and 2005, the birds were found to be absent from areas close to where they had previously been recorded and at most sites the birds were either absent or present at very low densities (A. Mack in litt. 2012).  Interviews with local people during these visits also found that many individuals were unfamiliar with the species (A. Mack in litt. 2012), although such interviews should be interpreted with caution. A total of 29 specimens were collected in two months in 1913 (Rothschild and Hartert 1914), suggesting either that this species’s favoured haunts have not been rediscovered or that it has undergone a steep decline. Also, there is said to be substantial logging on much of the island, as well as intense pressure from a growing human population (A. Mack in litt. 2012). As a result, this species may warrant uplisting to a higher category of threat. If it is reasonable to infer a continuing decline based on this information, ≥95% of mature individuals are in one subpopulation and the global population is <2,500 mature individuals, this species would qualify as Endangered under criterion C2a(ii) of the IUCN Red List. The Extent of Occurrence (EOO) of this species is currently estimated at 1,800 km2. If it is found at five or fewer locations and there is sufficient evidence to suggest that the population is in continuing decline due to degradation of its habitat, it may also qualify as Endangered under criterion B1ab(iii,iv,v). In addition, should there be sufficient evidence to suggest that the population has declined at a rate of ≥50% in three generations (13 years in this species), it would qualify as Endangered under criterion A2c+3c+4c. Subpopulations are defined by the IUCN as geographically or otherwise distinct groups in the population between which there is little demographic or genetic exchange (typically one successful migrant individual or gamete per year or less). Superb Pitta is currently assessed as having a single subpopulation on Manus. 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). For example, where the most serious plausible threat is habitat loss, a location is an area where a single development project can eliminate or severely reduce the population. Where the most serious plausible threat is volcanic eruption, hurricane, tsunami, frequent flood or fire, locations may be defined by the previous or predicted extent of lava flows, storm paths, inundation, fire paths, etc. Further information is required on this species’s likely population size, trends, distribution and subpopulation structure. References: Dutson, G. C. L. and Newman, J. L. (1991) Observations on the Superb Pitta Pitta superba and other Manus endemics. Bird Conservation International 1: 215-222. Rothschild, W. and Hartert, E. (1914) The birds of the Admiralty Islands, north of German New Guinea. Novitates Zoologicae 21: 281-298.

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2 Responses to Archived 2012-2013 topics: Superb Pitta (Pitta superba): uplist to Endangered?

  1. Guy Dutson says:

    Recognising how little we know, I agree with a continuing decline; ≥95% of mature individuals are in one subpopulation; and population is <2,500 mature individuals. Five or fewer locations is plausible given our knowledge, but it seems unlikely. A decline of ≥50% in three generations would seem unlikely and implausible given the apparent stability of the Rossun 'population'.

    [Could BirdLife check the reference "by 2007 only one bird could be located (G. Dutson in litt. 2007" – I believe that this refers to observations by Williams]

    • Joe Taylor says:

      Thank you very much Guy for your comments. The reference ‘G. Dutson in litt. 2007′ refers to observations by Phil Gregory.

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