Rufous-browed Hemispingus (Poospiza rufosuperciliaris): revise global status?

BirdLife species factsheet for Rufous-browed Hemispingus

Rufous-browed Hemispingus (Poospiza rufosuperciliaris) is restricted to the east Andes of north-central Peru. It is rare and locally distributed in the Cordillera de Colán, Amazonas, and the Cordillera Central, south to east La Libertad and the Carpish Mountains, Huánuco (Ridgely and Tudor 1989, Fjeldså and Krabbe 1990, Clements and Shany 2001, Schulenberg et al. 2007). It inhabits dense undergrowth in humid elfin forest near and just below the timberline, and shows a marked preference for extensive thickets of Chusquea bamboo (Ridgely and Tudor 1989). All records are at elevations of 2,500-3,500 m, but mostly above 2,800 m (Parker et al. 1996, Schulenberg et al. 2007).

The species is currently listed as Vulnerable under Criterion B1ab(i,ii,iii,v). Following a recalculation of the species’s extent of occurrence (EOO) based on a minimum convex polygon around all known range parts, the species no longer meets the threshold to be listed as threatened under this criterion. Hence, we are undertaking a review of the species’s Red List Category.

Our current information on the species’s conservation status will now be compared to all Red List Criteria.

Criterion A – We have no data on population trends. An analysis of forest loss from 2000 to 2012 found that forest within the species’s range was lost at a rate equivalent to 0.6% over three generation lengths (c.11 years) (Tracewski et al. 2016). We do not have evidence that the species is declining at a rate that approaches the thresholds for listing the species as threatened under Criterion A. The species is therefore assessed as Least Concern under this criterion.

Criterion B – The species’s Extent of Occurrence (EOO) is estimated at 32,989 km2, rounded to 33,000km2. This does not approach the threshold for listing the species as threatened under Criterion B1. The species’s area of occupancy (AOO) has not been quantified. Based on an analysis of remotely sensed data, the area of tree cover (with 50% canopy cover) within the species range in 2012 was 2,437 km2 (Tracewski et al. 2016). If we take this figure as a maximum AOO, the species could qualify for listing as Near Threatened under Criterion B2.However, to list the species as threatened on the Red List under Criterion B2, two of conditions a-c must also be met.

The species is not considered to be severely fragmented. The main threat to the species is forest clearance for grazing and agriculture. Forest loss is estimated to be occurring at a rate of 0.6% across three generations (Tracewski et al. 2016). The number of locations is, therefore, likely to be significantly greater than 10 and condition a is not met. Based on tree cover data (Tracewski et al. 2016), the extent of the species’s habitat is approximately stable, and we have no evidence that the species’s population size is undergoing a continuing decline. Condition b is not met. There is no evidence that the species’s population or range size are undergoing extreme fluctuations. Condition c is not met.

Although the species’s AOO could qualify the species as Near Threatened under Criterion B2, none of the three conditions are met. Therefore, the species is assessed as Least Concern under this criterion.

Criterion C – There are no known survey data for this species, but the population size has been previously estimated to fall within the band 2,500 – 9,999 individuals (SERFOR 2018). This roughly equates to 1,667-6,666 mature individuals, which is rounded here to 1,500-7,000 mature individuals. This meets the population size threshold for listing as Vulnerable under Criterion C. However, to list the species as threatened under Criterion C, further conditions must also be met.

Based on tree cover data (Tracewski et al. 2016), the extent of the species’s habitat is approximately stable, and we have no evidence that the species’s population size is undergoing a continuing decline. Based on the species’s distribution, it is likely to have at least two separate subpopulations. Based on the total population estimate and the species’s distribution, the largest subpopulation is likely to comprise more than 1,000 mature individuals, although it may approach the threshold of 1,000 mature individuals. Condition a(i) for Criterion C2 is not met at the level of Vulnerable. Based on the species’s range map, the majority of the range is fairly contiguous and could form a single subpopulation. However, the most northerly range part appears isolated and comprises around 9% of the total area of mapped range. From this information, it can be deduced that up to 91% of the population may be found in a single subpopulation. Consequently, condition 2a(ii) for is not met at the level of Vulnerable. There is no evidence that the species’s population size is undergoing extreme fluctuations so the species doesn’t meet condition b for Criterion C2.

Although the species’s population size falls beneath the threshold for listing the species as Vulnerable under Criterion C, we have no evidence for a continuing decline and none of the conditions for Criterion C2 are met. The species therefore qualifies as Least Concern under Criterion C.

Criterion D – Based on the population estimates described above, at the lower end of the estimate the species’s population size would approach the threshold for Vulnerable under Criterion D1 (1,000 mature individuals). The species can therefore be listed as Near Threatened, approaching the threshold for listing as threatened under Criterion D1.

The species does not have a restricted area of occupancy of number of locations such that deforestation could drive the species to Critically Endangered or Extinct within a very short time. The species does not therefore meet the criteria for listing as Vulnerable under Criterion D2.

Criterion E – To the best of our knowledge no quantitative assessment of the probability of extinction has been conducted for this species, and so it cannot be assessed against this criterion.

Based on the above assessment, it is proposed to list the Rufous-browed Hemispingus (Poospiza rufosuperciliaris) as Near Threatened, approaching the threshold for listing as threatened under Criterion D1. To allow us to achieve a clearer assessment of the species’s status, information is requested on the species’s population size or density, population trend and subpopulation structure.

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’s Red List status. Therefore, please make sure your comments are about the proposed listing.

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

Clements, J.F. and Shany, N. (2001) A field guide to the birds of Peru. Lynx Edicions, Barcelona, Spain.

Fjeldså, J. and Krabbe, N. (1990) Birds of the high Andes. Apollo Books, Copenhagen.

Parker, T.A., Stotz, D.F. and Fitzpatrick, J.W. (1996) Ecological and distributional databases. In: Stotz, D.F., Fitzpatrick, J.W., Parker, T.A. and Moskovits, D.K. (eds.), Neotropical bird ecology and conservation. University of Chicago Press, Chicago.

Ridgely, R.S. and Tudor, G. (1989) The birds of South America. University of Texas Press, Austin, Texas.

Schulenberg, T.S. (2007). Field guide to the birds of Peru: a biological assessment. C. Helm.

SERFOR (2018) Libro Rojo de la Fauna Silvestre Amenazada del Perú. Primera edición. Serfor (Servicio Nacional Forestal y de Fauna Silvestre), Lima, Peru.

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 Rufous-browed Hemispingus (Poospiza rufosuperciliaris): revise global status?

  1. Hannah Wheatley (BirdLife) 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.

  2. Hannah Wheatley (BirdLife) says:

    Recommended categorisation to be put forward to IUCN

    Following further review, the recommended categorisation for this species has been changed.

    Rufous-browed Hemispingus (Poospiza rufosuperciliaris) is now recommended to be listed as Least Concern.

    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.