This discussion was first published as part of the 2018 Red List update. At the time a decision regarding its status was pended, but to enable potential reassessment of this species as part of the 2019 Red List update this post remained open and the date of posting has been updated.
Black-headed Parrotbill (Psittiparus margaritae) is found on the Da Lat Plateau in southern Vietnam as well as into the adjacent Mondulkiri Province of eastern Cambodia. The species occurs in forest habitats, but can be found in more degraded areas such as plantations and forest scrub (S. Mahood in litt. 2012). However, it is unlikely that this species can persist in degraded habitats alone, and likely does require at least some forest (S. Mahood in litt. 2012). As such, the destruction of forest within its range is potentially leading to population declines.
It had been noticed that the Extent of Occurrence (EOO) of this species fell below the threshold for listing as Threatened, and the other conditions for listing as Threatened under the relevant criterion were also met. Therefore, following a re-calculation of the EOO using a Minimum Convex Polygon, a full re-assessment against all criteria has been conducted for this species using current information.
Criterion A – An analysis of deforestation rates by Tracewski et al. (2016) suggests that the rate of forest loss across this species’ range is 4.1% over three generations (13.8 years). From this information it may be inferred that while the species may be considered to be in decline, it is not declining at a rate thought to approach the threshold for Vulnerable under this criterion.
Criterion B – Its EOO has been calculated using a Minimum Convex Polygon (see IUCN 2001, 2012, Joppa et al. 2016) as 12,500km2. Tracewski et al. (2016) calculated the amount of forest within this species’ range (a proxy for the Area of Occupancy) in 2012 to be c.1,680km2. Therefore the species meets the threshold range values for consideration as Vulnerable under criteria B1 and B2. The evidence for a decline in forest area from Tracewski et al. means that at least the AOO, area/quality of habitat and population are considered to be in continuing decline. Finally, the species’ poor flight abilities means that its range may be considered ‘severely fragmented’ (S. Mahood in litt. 2012; see IUCN Standards and Petitions Subcommittee 2017). Therefore, it may warrant listing as Vulnerable under criteria B1ab(ii,iii,v)+2ab(ii,iii,v).
Criterion C – The population size has not been estimated, but the species has been described as uncommon to locally fairly common (del Hoyo et al. 2007). Therefore, it is not considered to warrant listing under this criterion.
Criterion D – As above, it is not thought to approach the threshold population size under this criterion; and it is also not thought to be restricted to a limited AOO or number of locations with a threat severe enough to drive it to CR/EX in a short space of time. Therefore, it does not warrant listing as threatened under this criterion.
Criterion E – To the best of our knowledge no quantitative analysis of extinction risk has been carried out for this species. Thus, it is not possible to assess this species against this criterion.
Therefore, the species likely warrants listing as Vulnerable under criteria B1ab(ii,iii,v)+2ab(ii,iii,v), though comments are welcome and the species may warrant retaining as Near Threatened if its range may be considered fragmented rather than ‘severely fragmented’.
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 about the proposed listing.
del Hoyo, J.; Elliott, A.; Christie, D. 2007. Handbook of the Birds of the World, vol. 12: Picathartes to Tits and Chickadees. Barcelona, Spain: Lynx Edicions.
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.
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.