White-streaked Antvireo (Dysithamnus leucostictus): revise global status?

BirdLife species factsheet for White-streaked Antvireo

White-streaked Antvireo (Dysithamnus leucostictus) occurs in north-western South America. Its range is disjunt; the nominate subspecies ranges along the eastern slopes of the Andes from central Colombia to northern Peru, while subspecies tucuyensis occurs in northern Venezuela and Suriname. The species is restricted to undisturbed montane forest at elevations up to 2,000 m (Zimmer et al. 2020). The population size has not been quantified, but the species is described as uncommon to locally common (Stotz et al. 1996, Zimmer et al. 2020).

White-streaked Antvireo is susceptible to forest fragmentation and edge effects, and the only threat known to the species is habitat loss. A study of deforestation in the Amazon projected rapid forest loss and fragmentation within the range and consequently rapid population declines of over 30% over three generations (Soares-Filho et al. 2006, Bird et al. 2011). However, new information regarding the rate of forest loss suggests that this was an overestimation, as large parts of the species’s range are covered by protected areas and to date largely unaffected by logging (Tracewski et al. 2016, Global Forest Watch 2020, O. Ottema in litt. 2020). 

White-streaked Antvireo is currently listed as Vulnerable under Criterion A3c, based on projections of rapid habitat loss in the future (BirdLife International 2020). However, new information regarding trends in population size and habitat availability suggests 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 estimated directly. Forest loss over the past ten years (one generation length being estimated at 3.0 years; Bird et al. 2020*) within the range has been very low (potentially <3%; Tracewski et al. 2016, Global Forest Watch 2020). The species is highly forest-dependent, and population declines may be exacerbated by habitat degradation, so that the rate of population decline might exceed the rate of forest loss. Nevertheless, population declines are unlikely to surpass 10% over ten years, and as such White-streaked Antvireo may be considered Least Concern under this criterion.

Criterion B – The Extent of Occurrence (EOO) for this species is 2,240,000 km2. This is too large to warrant listing as threatened under Criterion B1, and White-streaked Antvireo 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 population size of White-streaked Antvireo has not been quantified, and therefore the species cannot be assessed against Criterion C. Considering the range size, the availability of large areas of undisturbed habitat and the fact that the species is regularly observed at many sites throughout the range, it is assumed that the species by far exceeds the threshold for listing as threatened under this criterion.

Criterion D – The population size has not been quantified, as thus the species cannot be assessed against Criterion D1. It is however assumed that the species does not qualify as threatened under this criterion. Moreover, the range is too large to warrant listing as threatened 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 White-streaked Antvireo (Dysithamnus leucostictus) 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).

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.; Buchanan, J. M.; Lees, A. C.; Clay, R. P.; Develey, P. F.; Yépez, I.; Butchart, S. H. M. 2011. Integrating spatially explicit habitat projections into extinction risk assessments: a reassessment of Amazonian avifauna incorporating projected deforestation. Diversity and Distributions 18(3): 273-281.

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: Dysithamnus leucostictus. http://www.birdlife.org (Accessed 31 March 2020).

Global Forest Watch. 2020. Interactive Forest Change Mapping Tool. http://www.globalforestwatch.org (Accessed 31 March 2020).

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.

Soares-Filho, B. S.; Nepstad, D. C.; Curran, L. M.; Cerqueira, G. C.; Garcia, R. A.; Ramos, C. A.; Voll, E.; McDonald, A.; Lefebvre, P.; Schlesinger, P. 2006. Modelling conservation in the Amazon basin. Nature 440(7083): 520-523.

Stotz, D. F., Fitzpatrick, J. W., Parker, T. A.; Moskovits, D. K. 1996. Neotropical Birds: Ecology and Conservation. University of Chicago Press, Chicago, USA.

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.

Zimmer, K.; Isler, M. L.; Sharpe, C. J. 2020. White-streaked Antvireo (Dysithamnus leucostictus), version 1.0. In: del Hoyo, J.; Elliot, A.; Sargatal, D. A.; Christie, D. A.; de Juana, E. (eds.). Birds of the World. Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.whsant4.01 (Accessed 31 March 2020).

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4 Responses to White-streaked Antvireo (Dysithamnus leucostictus): revise global status?

  1. Otte H. Ottema says:

    I agree that White-streaked Antvireo (Dysithamnus leucostictus) be listed as Least Concern.

  2. 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 1.2% 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.

  3. Red List Team (BirdLife International) says:

    Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested by so many people in commenting. 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 once again,
    BirdLife Red List Team

  4. 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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