Archived 2020 topic: Sira Tanager (Tangara phillipsi): revise global status?

BirdLife species factsheet for Sira Tanager

Sira Tanager (Tangara phillipsi) is endemic to the Cerros del Sira in eastern central Peru. It is found in humid scrub and along the edges of montane forest, preferring open habitats such as elfin and short-stature forest and openings along watercourses (Harvey 2020). It occurs at elevations of 1,300-2,200 m (G. Harvey in litt. 2020). The species is described as fairly common to common in suitable habitat (Harvey 2020). Assuming that the species occurs at the same density as congeners (1-22 individuals/km2; Santini et al. 2018), Sira Tanager might number roughly 3,650-80,000 individuals, equating to 2,400-53,500 mature individuals.

Threats to the species include habitat loss through mining and small-scale logging, which have been ongoing near the base of the Cerros del Sira for some time (Mee et al. 2002). However, large parts of its range were found to be in pristine condition during surveys in 2000 and 2008 (A. Mee in litt. 2001, Mee et al. 2002, Harvey et al. 2011, M. Harvey in litt. 2020) and forest loss is low to date (Tracewski et al. 2016, Global Forest Watch 2020). In the future though, Sira Tanager may potentially be impacted by a reduction in habitat availability as a consequence of climate change (Harvey 2020).

Sira Tanager is currently listed as Near Threatened, approaching the threshold for listing as threatened under Criterion D2 (BirdLife International 2020). However, new information regarding the population trend and a review of the available data on the distribution range suggest that the species may warrant a change in Red List status. Therefore, it will be re-assessed against all Red List criteria:

Criterion A – The population trend has not been assessed directly. Forest loss within the range has been very low over the last ten years (potentially < 3%; Tracewski et al. 2016, Global Forest Watch 2020; one generation length being 2.9 years; Bird et al. 2020*), and large areas still seemed pristine (Mee et al. 2002, Harvey et al. 2011). As the species is not confined to forest interior, but also occurs at edges and in scrub habitat, the very low rates of forest loss are unlikely to impact the population size, and the species is tentatively assessed as stable. It therefore qualifies for Least Concern under this criterion.

Criterion B – The species occurs in a small range (Extent of Occurrence = 8,100 km2). However, given the continuity of habitat within the range and the lack of any imminent threats, the species cannot be considered to be severely fragmented sensu IUCN (IUCN Standards and Petitions Committee 2019) or occurring at a limited number of locations**. There are no continuing declines nor extreme fluctuations inferred, estimated or observed in availability of habitat or population size. Therefore, the species does not qualify for listing as threatened under Criterion B and may be considered Least Concern under this criterion.

Criterion C – The global population is preliminarily estimated to number 2,400-53,500 mature individuals. Assuming that the true population size is closer to the lower end of the estimate, the species would meet the threshold for listing as threatened under Criterion C. The species is however assessed as being stable. There is no information regarding the population structure, but it is unlikely that the largest subpopulation contains less than 1,000 mature individuals. Therefore, as the species meets only one out of three conditions, it does not warrant listing as threatened under Criterion C and is therefore considered Least Concern under this criterion.

Criterion D – The global population size and range are too large to warrant listing as threatened under Criterion D and Sira Tanager is therefore considered 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 suggested that Sira Tanager (Tangara phillipsi) be listed as Least Concern. We welcome any comments on the 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. 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).

**The term ‘location’ refers to a distinct area in which a single threatening event can rapidly affect all individuals of the taxon present, with the size of the location depending on the area covered by the threatening event. 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

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.

BirdLife International. 2020. Species factsheet: Tangara phillipsi. http://www.birdlife.org (Accessed 11 March 2020).

Global Forest Watch. 2020. World Resources Institute. http://www.globalforestwatch.org (Accessed 11 March 2020).

Harvey, M. G. 2020. Sira Tanager (Stilpnia phillipsi), version 1.0. In: Schulenberg, T. S. (ed.). Birds of the World. Cornell Lab of Ornithology, Ithaca, New York, USA.

Harvey, M. G.; Winger, B. M.; Seeholzer, G. F.; Cáceres, D. 2011. Avifauna of the Gran Pajonal and Southern Cerros Del Sira, Peru. The Wilson Journal of Ornithology 123(2): 289-315.

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.

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.

Mee, A.; Ohlson, J.; Stewart, I.; Wilson, M.; Örn, P.; Ferreyra, J. D. 2002. The Cerros del Sira revisited: birds of submontane and montane forest. Cotinga 18: 46-57.

Santini, L.; Isaac, N. J. B.; Ficetola, G. F. 2018. TetraDENSITY: A database of population density estimates in terrestrial vertebrates. Global Ecology and Biogeography 27: 787-791.

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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4 Responses to Archived 2020 topic: Sira Tanager (Tangara phillipsi): 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 2.4% 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.

  4. Red List Team (BirdLife International) says:

    Recommended categorisation to be put forward to IUCN

    The final categorisation for this species has not changed. Sira Tanager is recommended to be listed as Least Concern.

    Many thanks for everyone who contributed to the 2020 GTB Forum process. 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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