Archived 2019 topic: Macgregor’s Honeyeater (Macgregoria pulchra): revise global status?

BirdLife species factsheet for Macgregor’s Honeyeater: http://datazone.birdlife.org/species/factsheet/macgregors-honeyeater-macgregoria-pulchra

Macgregor’s Honeyeater (Macgregoria pulchra) occurs in subalpine forest dominated by its main food-plant, Dacrycarpus compactus,in the highlands of New Guinea. Small, disjunct populations occur in the Oranje, Snow and Star Mountains of Papua, Indonesia, and the Owen Stanley and Wharton Ranges of Papua New Guinea. The fact that the species is absent from large areas of the central highlands of the island suggests that there have been historical extinctions due to key threats such as habitat change and hunting pressure (Barker and Croft 1977, Frith and Beehler 1998). Yet, data from Tracewski et al. (2016) show no forest loss within this species’s range between 2000 and 2012. In the Star Mountains, the species is protected for cultural reasons by the Ketengban people (Frith and Beehler 1998). Elsewhere, though, it is a popular game bird due to it being tame, site-faithful and quite conspicuous (Beehler 1981, Frith and Beehler 1998), and it has become rare in several areas. It does inhabit remote areas that are inaccessible to hunters, but the development of new roads, such as in Wamena, enables greater access, and subsequently the species has declined at this site (P. Gregory in litt. 1999, D. Gibbs in litt. 2000).

Currently listed as Vulnerable (BirdLife International 2018), an analysis of deforestation data by Tracewski et al. (2016) has shown that the amount of forest remaining within the species’s range is very limited, and as such it could warrant a change in Red List status. Therefore, it has been reassessed here against all criteria.

The initial topic on this analysis can be found here.

Criterion A – Data from Tracewski et al. (2016) appears to show no forest loss within this species’s range between 2000 and 2012, and in the Star Mountains it is protected for cultural reasons by the Ketengban people (Frith and Beehler 1998). But the species is considered to be declining elsewhere as a result of ongoing hunting activities. The rate of decline, however, has not been estimated. The species, therefore, cannot be accurately assessed against this criterion, but it is suspected that the rate of decline does not approach the threshold for Vulnerable (30% over three generations [17.4 years]).

Criterion B – The species’s Extent of Occurrence is too large (131,000km2) to warrant listing under Criterion B1. Tracewski et al. (2016) estimated the maximum Area of Occupancy (AOO) (calculated as the remaining tree area within the species’s range) to be c.408km2. This falls below the threshold value for Endangered under Criterion B2, but to be listed as such requires at least two other conditions to be met.

The deforestation analysis shows no forest loss within the species’s range between 2000 and 2012 (per Tracewski et al. 2016), and so there are no ongoing declines in habitat availability. However, ongoing hunting means that it is likely that the species is undergoing a continuing decline in population size. Therefore, condition b(v) would be met.

While the species may show a degree of nomadism, and may alter its breeding cycle to fit with the unpredictable nature of its main food plant (Beehler 1981, Beehler 1983, Beehler 1991a,b, Hicks and Burrows 1992, Frith and Beehler 1998), it is not thought to undergo extreme fluctuations per IUCN definitions (see IUCN Standards and Petitions Subcommittee 2017). Therefore, condition c) is not met.

To be listed as Endangered, the species’s range would need to be severely fragmented or the species would need to occur at 5 or fewer locations*. The number of locations where the species occurs likely falls in the range 6-10, and so the species at least warrants listing as Vulnerable under Criterion B2ab(v). Whether it also triggers the conditions for listing as Endangered is dependent on whether the species is considered to be severely fragmented or not per IUCN Standards and Petitions Subcommittee (2017). To be listed as such would require >50% of its AOO to be in patches separated by a large distance, and to be smaller than required to support a viable population. The first part of this is met, as occupied patches are separated by a large distance, but it is uncertain whether they are too small to support viable populations. It could be precautionary to assess the species’s habitat as being severely fragmented, and as such list it as Endangered under Criterion B2ab(v), but further information is requested.

Criterion C – Based on range size, descriptions of abundance and known records, the population size is currently placed in the band 2,500-9,999 mature individuals (see BirdLife International 2018). The species is inferred to be in decline, but the rate of decline is not known, and so it does not warrant listing under Criterion C1. The species is not known to undergo extreme fluctuations, so it cannot be listed under Criterion C2b either.

The species does occur in multiple subpopulations, meaning it cannot be listed under Criterion C2a(ii), but, as in its current listing, it is precautionarily suspected that no single subpopulation contains >1,000 mature individuals. Therefore, the species warrants listing as Vulnerable under Criterion C2a(i).

Criterion D – The species’s population size and range are too large to warrant listing under this criterion. As such, it Macgregor’s Honeyeater may be assessed as Least Concern under Criterion D.

Criterion E – To the best of our knowledge there has been no quantitative analysis of extinction risk conducted for this species. Therefore, it cannot be assessed against this criterion.

Therefore, the species either warrants listing as Endangered under Criterion B2ab(v) or Vulnerable under Criteria B2ab(v); C2a(i). We welcome further comments or information, but please note that this topic is not designed to be a general discussion about the ecology of the species, rather a discussion of the species’ Red List status. Therefore, please make sure your comments are relevant to the information that is sought, or about the species’ Red List status.

*The term ‘location’ refers to a distinct area in which a single threatening event can rapidly affect all individuals of the taxon present, with the size of the location depending on the area covered by the threatening event. 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).

An information booklet on the Red List Categories and Criteria can be downloaded here and the Red List Criteria Summary Sheet can be downloaded here. Detailed guidance on IUCN Red List terms and definitions and the application of the Red List Categories and Criteria can be downloaded here.

References

Barker, W. R.; Croft, J. R. 1977. The distribution of Macgregor’s Bird-of-paradise. Emu 77: 219-222.

Beehler, B. 1981. Ecological structuring of forest bird communities in New Guinea. In: Gressitt, J.L. (ed.), Monographie biologicae, pp. 837-861. Dr W. Junk Publishers, The Hague.

Beehler, B. M. 1983. Notes on the behavior and ecology of Macgregor’s Bird-of-paradise. Emu 83: 28-30.

Beehler, B. M. 1991a. A naturalist in New Guinea. University of Texas Press, Austin, Texas.

Beehler, B. M. 1991b. Papuan New Guinea’s wildlife and environments-what we don’t yet know. In: Pearl, M.; Beehler, B.; Allison, A.; Taylor, M. (ed.), Conservation and environment in Papua New Guinea: establishing research priorities, pp. 1-10. Wildlife Conservation International, New York.

BirdLife International. 2018. Species factsheet: Macgregoria pulchra. Downloaded from http://www.birdlife.org on 18/09/2018.

Frith, C. B.; Beehler, B. M. 1998. The birds of paradise. Oxford University Press, Inc, New York.

Hicks, R. K.; Burrows, I. 1992. Port Moresby ringing report: 1988. Muruk 5(2): 66-84.

IUCN. 2001. IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, U.K.

IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1. Second edition. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, U.K. Available at: www.iucnredlist.org/technical-documents/categories-and-criteria.

IUCN Standards and Petitions Subcommittee. 2017. Guidelines for Using the IUCN Red List Categories and Criteria. Version 13. Prepared by the Standards and Petitions Subcommittee. Downloadable from http://www.iucnredlist.org/documents/RedListGuidelines.pdf.

Tracewski, Ł.; Butchart, S. H. M.; Di Marco, M.; Ficetola, G. F.; Rondinini, C.; Symes, A.; Wheatley, H.; Beresford, A. E.; Buchanan, G. M. 2016. Toward quantification of the impact of 21st-century deforestation on the extinction risk of terrestrial vertebrates. Conservation Biology 30: 1070-1079.

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2 Responses to Archived 2019 topic: Macgregor’s Honeyeater (Macgregoria pulchra): revise global status?

  1. Guy Dutson says:

    The species’ range has not been fragmented in historic times from either anthropogenic change to habitat or hunting. There is no direct evidence for historical anthropogenic changes causing its currently fragmented range but this remains a viable possibility. Based on limited experience of the species at just one site, I think it more likely that its range is naturally disjunct because of the natural rarity of its specialised habitat requirements, and that anthropogenic changes have had a minor impact.

  2. Hannah Wheatley (BirdLife) says:

    Preliminary proposal

    Based on available information, our preliminary proposal for the 2019 Red List would be to list Macgregor’s Honeyeater (Macgregoria pulchra) as Vulnerable under Criteria B2ab(v); C2a(i).

    There is now a period for further comments until the final deadline in mid-July, 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 2019 Red List categories will be published on the BirdLife and IUCN websites in December, following further checking of information relevant to the assessments by both BirdLife and IUCN.

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