Rufous-bellied Mountain-tanager (Pseudosaltator rufiventris): revise global status?

BirdLife species factsheet for Rufous-bellied Mountain-tanager

Rufous-bellied Mountain-tanager (Pseudosaltator rufiventris) occurs in the eastern Andes of Bolivia and Argentina. It inhabits shrubby or open habitats, scrubland and woodland at elevations of 2,500-4,000 m, and is also found in agricultural land (Remsen et al. 1988, Fjeldså and Mayer 1996, Pearman 1997, Mazar Barnett et al. 1998). The species is in general uncommon, but can be locally common (Stotz et al. 1996, Pearman 1997, S. Mayer in litt. 1999), and is potentially more widespread than known to date. The population in Bolivia is thought to exceed 10,000 individuals (S. Mayer in litt. 1999), which roughly equates to more than 6,500 mature individuals. Therefore, the global population is here tentatively placed in the band 10,000-19,999 mature individuals. The species is threatened by habitat loss, as scrub and native woodland patches are being fragmented and converted to agricultural uses (Remsen et al. 1988, Mazar Barnett et al. 1998), which is probably causing some population declines.

Rufous-bellied Mountain-tanager is currently listed as Near Threatened, approaching the threshold for listing as threatened under Criterion C2a(i). However, new information regarding trends in habitat availability suggests that the species may warrant a change in Red List status. Therefore, it will be re-assessed against all criteria:

Criterion A – The population trend has not been estimated directly. The only threat known to the species is habitat loss, and it is suspected that the conversion of native scrub and woodland for agricultural use is causing a slow population decline, but we have no information on the exact rate of decline. Forests loss within the range has been negligible over the past three generations (<1% over 10.2 years*; Tracewski et al. 2016). It is unlikely that the combined impacts of the loss of forests and the loss of scrubland on the population size is causing a population decline of >10% over three generations and thus, Rufous-bellied Mountain-tanager is listed as Least Concern under Criterion A.

Criterion B – The Extent of Occurrence (EOO) for this species is 247,000 km2. This is too large to warrant listing as threatened under Criterion B1, and Rufous-bellied Mountain-tanager qualifies for Least Concern under this criterion. The Area of Occupancy (AOO) has not been quantified according to IUCN guidelines (IUCN Standards and Petitions Committee 2019), and so the species cannot be assessed against Criterion B2.

Criterion C – The global population is tentatively placed in the band 10,000-19,999 mature individuals. Assuming that the true population size is closer to the lower end of the estimate, the species approaches the threshold for listing as threatened under Criterion C. However to do so, further conditions must be met.

The species is suspected to decline at <10% over three generations. Sub-criterion 1 is not met. We have no information on the subpopulation structure; however based on observational records (see eBird 2020) it seems that the species forms at least two relatively large subpopulations, the largest of which likely holds considerably more than 1,000 mature individuals. Hence, sub-criterion 2a is not met. There is no evidence that the population size is undergoing extreme fluctuations, and sub-criterion 2b is not met. Overall, Rufous-bellied Mountain-tanager does not meet nor approach sufficient conditions to warrant listing as threatened or Near Threatened under Criterion C. It is therefore considered Least Concern under this criterion.

Criterion D – We have no information on the population size, and the species cannot be assessed against Criterion D1. The range is too large to approach the threshold for Vulnerable under Criterion D2, and therefore Rufous-bellied Mountain-tanager may be listed as Least Concern under Criterion D2.

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 suggested that Rufous-bellied Mountain-tanager (Pseudosaltator rufiventris) be listed as Least Concern. We welcome any comments on the proposed listing and specifically request up-to-date information on the population size.

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. By submitting a comment, you confirm that you agree to the Comment Policy.

*Bird generation lengths are estimated using the methodology of Bird et al. (2020), as applied to parameter values updated for use in each IUCN Red List for birds reassessment cycle. Values used for the current assessment are available on request. We encourage people to contact us with additional or improved values for the following parameters; adult survival (true survival accounting for dispersal derived from an apparently stable population); mean age at first breeding; and maximum longevity (i.e. the biological maximum, hence values from captive individuals are acceptable).

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

Bird, J. P.; Martin, R.; Akçakaya, H. R.; Gilroy, J.; Burfield, I. J.; Garnett, S.; Symes, A.; Taylor, J.; Šekercioğlu, Ç.; Butchart, S. H. M. (2020). Generation lengths of the world’s birds and their implications for extinction risk. Conservation Biology online first view.

Fjeldså, J.; Mayer, S. 1996. Recent ornithological surveys in the Valles region, southern Bolivia and the possible role of Valles for the evolution of the Andean avifauna.

IUCN Standards and Petitions Committee. 2019. Guidelines for using the IUCN Red List Categoreis and Criteria. Version 14. http://www.iucnredlist.org/documents/RedListGuidelines.pdf.

Mazar Barnett, J.; Clark, R.; Bodrati, A.; Bodrati, G.; Pugnali, G.; della Seta, M. 1998. Natural history notes on some little-known birds in north-west Argentina. Cotinga: 64-75.

Pearman, M. 1997. Rufous-bellied Saltator Saltator rufiventris. Cotinga: 73-74.

Remsen, J. V.; Schmitt, C. G.; Schmitt, D. C. 1988. Natural history notes on some poorly known Bolivian birds, 3. Le Gerfaut 78: 363-381.

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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3 Responses to Rufous-bellied Mountain-tanager (Pseudosaltator rufiventris): revise global status?

  1. Red List Team (BirdLife International) says:

    Global Forest Change data on tree cover loss up to 2019 have now been released and made available via Global Forest Watch. Based on these data, over ten years approximately 0.9% of tree cover with >30% canopy cover was lost from within the species’s range (Global Forest Watch 2020). This does not affect the above assessment under Criterion A.

  2. Red List Team (BirdLife International) says:

    The window for consultation is now closed. We will analyse and interpret the new information and post a preliminary decision on this species’s Red List status on this page in early July.

    Thank you,
    BirdLife Red List Team

  3. Red List Team (BirdLife International) says:

    Preliminary proposal

    Based on available information, our preliminary proposal for the 2020 Red List would be to adopt the proposed classification 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 2020 Red List categories will be published on the BirdLife and IUCN websites in December 2020/January 2021, following further checking of information relevant to the assessments by both BirdLife and IUCN.

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