Flores Hanging-parrot (Loriculus flosculus): revise global status?

BirdLife species factsheet for Flores Hanging-parrot    

Flores Hanging-parrot (Loriculus flosculus) is endemic to Flores and satellite islands in Indonesia. It occupies a narrow altitudinal band between 800 and 1200 m, but has occasionally been recorded down to 450 m (Collar et al. 2018). The species almost exclusively occurs in moist evergreen and semi-deciduous forests. Its range apparently closely equates to that of these two forest-types on Flores, although it occasionally visits degraded roadside habitat.

The population is estimated to number 2,500-9,999 mature individuals. Even though the species is locally common, its overall rarity cannot be disputed, and its restricted habitat and altitudinal range suggest that it must be both numerically constrained and susceptible to further habitat loss.

Flores Hanging-parrot is considered to be in decline. The most pertinent threat to the species is the destruction of its habitat. Moist evergreen and semi-deciduous forests on Flores are being cleared for agriculture, firewood collection, commercial logging and timber extraction. Little forest below 1,000 m is included within protected areas on Flores. Even within those areas that receive protection, illegal logging is continuing as there is virtually no governmental enforcement of laws.

This threat invariably reduces the species’s range and population. Currently, Flores Hanging-parrot is listed as Endangered under Criterion B1ab(ii,iii,iv,v), indicating a very small Extent of Occurrence (EOO) and declines in population size and habitat availability.

Following IUCN guidelines, the EOO for this species has been re-calculated using a Minimum Convex Polygon, which is “the smallest polygon in which no internal angle exceeds 180 degrees and which contains all the sites of occurrence” (IUCN 2001, 2012, Joppa et al. 2016). After re-calculating the EOO for Flores Hanging-parrot, this species appears to warrant a change in Red List status. Therefore, we present here our reassessment against all criteria for the species.

The initial topic on this analysis can be found here.

Criterion A – Tracewski et al. (2016) measured the forest loss within this species’s range between 2000 and 2012 as c. 28 km2. This roughly equates to a rate of forest loss of 4% over three generations (13.2 years) for this species, with the assumption that habitat loss has continued at the same rate to the present day.Population changes may be proportional to forest cover change. Even though Flores Hanging-parrot is strictly depending on mature forest, it is highly unlikely that the rate of population decline based on habitat loss alone approaches the threshold for Vulnerable. Therefore, Flores Hanging-parrot may be listed as Least Concern under this criterion.

Criterion B – Using a Minimum Convex Polygon, the Extent of Occurrence (EOO) has been calculated as 13,400 km2, which meets the threshold for listing as Vulnerable under Criterion B1 (EOO < 20,000 km2). The area covered by forest within the range has been calculated as 876 km2 (Tracewski et al. 2016). We can tentatively assume that for a highly forest-dependent species like Flores Hanging-parrot, the area of forested habitat equals the maximum Area of Occupancy (AOO); as such the the maximum AOO meets the threshold for Vulnerable under Criterion B2 (AOO < 2,000 km2). Flores Hanging-parrot is known from currently four locations*, while its AOO, habitat quality, number of locations and population size are in decline. Thus, the species may be listed as Vulnerable under Criterion B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v).

Criterion C – The population of Flores Hanging-parrot is estimated to number 2,500-9,999 mature individuals. This may warrant listing the species under Criterion C, given it is considered to be declining, as long as other conditions are met. As the rate of population decline has been inferred from the rate of forest loss, Flores Hanging-parrot cannot be assessed fully against Criterion C1. Given the small distribution range, the species can be considered to form just one subpopulation. Therefore, unless the population estimate is revised, Flores Hanging-parrot may be listed as Vulnerable under Criterion C2a(ii).

Criterion D – The population size of this species is estimated at 2,500-9,999 mature individuals. Therefore, unless the population estimate is revised, it may be listed as Least Concern under this criterion.

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

Therefore, it is proposed that Flores Haning-parrot (Loriculus flosculus) be listed as Vulnerable under Criteria B1ab(ii,iii,iv,v)+2ab(ii,iii,iv,v); C2a(ii). We welcome any comments on this proposed listing.

Please note that this topic is not designed to be a general discussion about the ecology of the species, rather a discussion of its Red List status. Therefore, please make sure your comments are relevant to the discussion outlined in the topic.

*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).

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

Collar, N.; de Juana, E.; Boesman, P. 2018. Flores Hanging-parrot (Loriculus flosculus). 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, Spain. https://www.hbw.com/node/54591 (Accessed 13 September 2018).

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. www.iucnredlist.org/technical-documents/categories-and-criteria.

Joppa, L.N.; Butchart, S.H.M.; Hoffmann, M.; Bachman, S.P.; Akçakaya, H.R.; Moat, J.F.; Böhm, M.; Holland, R.A.; Newton, A.; Polidoro, B.; Hughes, A. 2016. Impact of alternative metrics on estimates of extent of occurrence for extinction risk assessment. Conservation Biology 30: 362-370. 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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1 Response to Flores Hanging-parrot (Loriculus flosculus): revise global status?

  1. Rob Martin (BirdLife International) says:

    Preliminary proposal

    Based on available information, our preliminary proposal for the 2019 Red List would be to adopt the proposed classifications outlined in the initial forum discussion.

    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 those in 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.

Comments are closed.