Current view: Data table and detailed info
Taxonomic note
This distinctive new species was described from the island of Wangi-Wangi in the Wakatobi Archipelago, Indonesia, by Irham et al. (2023). Monotypic.
Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2023. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 8. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v8_Dec23.zip.
IUCN Red List criteria met and history
Red List criteria met
Red List history
| Migratory status |
not a migrant |
Forest dependency |
high |
| Land-mass type |
|
Average mass |
- |
Population justification: Descriptively, this species is described as locally common (O'Connell et al. 2020, Eaton et al. 2021), but in eBird checklists generated (eBird 2023), it is evidently rarer than Z. flavissimus, with almost no search effort finding more then five individuals (where counts of 20+ Z. flavissimus are not uncommon). Based on 16 transects across the island, a density of 0.2 birds/hectare, or 20 birds/km2, was recorded in 2012/13 (unpublished data: D. O'Connell, S. Kelly and Adi Karya pers. comm.). The area of suitable habitat across Wangi-wangi is c. 60-80 km2, suggesting that the island may host up to c. 1,600 birds. However, there are numerous assumptions being made in this estimate which require consideration. First, all transects used to derive it were placed in secondary-type habitat, with qualitative reports (O'Connell et al. 2020, Menner 2023) that the species occurs at higher densities in the island's taller forests; because the area of taller forest is relatively small (c. 10 km2), it is suspected that even if birds here occur at a much higher density, the total population is unlikely to exceed 2,500 birds. Second, not all of the birds encountered will have been mature individuals. Third, data were collated 10 years ago, with evidence that the species may have been subject to trapping pressure and reduced in number since (see Population Trend). In the absence of data from which to derive robust minimum and maximum population bounds, it should be noted that the limits used here are somewhat arbitrary, albeit with relatively high confidence that they encapsulate all plausible scenarios. The total number of birds is estimated to number 800-2,500 birds, or 500-2,500 mature individuals, with a best estimate of 500-1,500 mature individuals.
Trend justification: The population is inferred to be declining because of two key threats: (1) habitat loss and degradation; and (2) trapping for the songbird trade.
Over the past ten years (2012-2022), remote sensing data indicate that approximately 5% of forest cover on Wangi-wangi has been lost (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein). This is thought to have some impact on the population size of this species, especially given many losses have been recorded in areas of more mature forest, where where this species is reportedly commonest (O' Connell et al. 2020; Menner 2021, 2023). However, there is also evidence that it persists in degraded habitats (O'Connell et al. 2020, eBird 2023, unpublished data: D. O'Connell, S. Kelly and Adi Karya pers. comm.) such that not all forest loss may directly impact the population size, although Menner (2023) regarded it 'dependent' on taller vegetation and 'sensitive to human habitat alteration'. Consequently habitat loss and degradation is suspected of causing some slow declines, with most impacts of this threat having been historical.
The second, perhaps most serious, threat to this species (trapping) is considerably harder to quantify, especially in the absence of repeated survey effort. The species has already been recorded in the songbird trade (O' Connell et al. 2020, Asian Songbird Trade Specialist Group in litt. 2023) but the impact this is having on wild populations is currently improperly known. However, observations in O'Connell et al. (2020), from a decade ago, that it was readily found and mist-netted in degraded habitats were not repeated by Menner (2021), who found it only, after several days of effort (albeit not at typically an optimal time of day), in mature habitat. More recently, Menner (2023) continued to find it distributed 'throughout the island'. Acknowledging that trappers are capable of such pressure (as demonstrated elsewhere in Indonesia), and the anecdotal reports that the species has indeed declined over the past decade, it is accepted that the species is undergoing a continuing decline, although in the absence of repeated surveys, the rate of this decline is not currently estimated. Elucidating this should be considered an utmost research priority.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Wangi-Wangi White-eye Zosterops paruhbesar. Downloaded from
https://datazone.birdlife.org/species/factsheet/wangi-wangi-white-eye-zosterops-paruhbesar on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/11/2024.
