Archived 2019 topic: Belted Flycatcher (Xenotriccus callizonus): revise global status?

BirdLife species factsheet for Belted Flycatcher

Belted Flycatcher (Xenotriccus callizonus) occurs in southern Mexico (Chiapas), Guatemala, northwestern El Salvador (Howell and Webb 1995), and has recently been reported from southwestern Honduras (Haldeman 2015). The species is uncommon, locally distributed and generally not well known (del Hoyo et al. 2004). Partners in Flight estimate the global population to number fewer than 50,000 mature individuals (A. Panjabi in litt. 2017), which is why the species was placed in the band 20,000-49,999 mature individuals by BirdLife International (2018). The species occupies the understorey of dense, scrubby forests and woodland, preferably with oaks (Quercus), between 1,200 and 2,000 m (Howell and Webb 1995).

The population is suspected to be in decline owing to ongoing habitat destruction. Forests are subject to intense clearance throughout the region, owing principally to coffee cultivation (Stattersfield et al. 1998) and logging, as well as uncontrolled fires (del Hoyo et al. 2004). Belted Flycatcher’s preferred habitats, oak forest and woodland, have suffered heavy deforestation throughout the range (K. Eisermann in litt. 2010).

Belted Flycatcher is currently listed as Near Threatened under Criterion B1ab(i,ii,iii) (BirdLife International 2018). However, this is no longer tenable because this was based on an Extent of Occurrence (EOO) value calculated as the ‘area of mapped range’. This is no longer appropriate, and the EOO should be calculated using a Minimum Convex Polygon (see IUCN 2001, 2012, Joppa et al. 2016), as EOO is a measure of the spatial spread of areas occupied by a species, not the actual area it occupies. After re-calculating the EOO for Belted Flycatcher, this species appears to warrant a change in Red List status. Therefore, we present here our reassessment against all criteria for the species.

Criterion A – The population of Belted Flycatcher it suspected to be in decline, but the rate of decline has not been estimated directly. Tracewski et al. (2016) measured the forest loss within the species’s range between 2000 and 2012 as c. 287 km2. This roughly equates to a rate of forest loss of 4.0% over three generations (10.8 years) for this species. Belted Flycatcher depends on dense woodland and the only known threat is habitat loss. We can tentatively assume that the population has declined at the same rate as the forest cover, and thus the species is inferred to have undergone a reduction of 4.0% over the past 10.8 years. Overall, the rate of decline is too slow to approach the threshold for Vulnerable under this criterion. Therefore, Belted Flycatcher may be listed as Least Concern under Criterion A.

Criterion B – The newly calculated Extent of Occurrence (EOO) for this species is 83,800 km2. This does not meet the threshold for Vulnerable (EOO < 20,000 km2). Therefore, Belted Flycatcher may be listed as Least Concern under Criterion B1. The Area of Occupancy (AOO) has not been calculated and Belted Flycatcher cannot be assessed against Criterion B2.

Criterion C – The global population is estimated to number fewer than 50,000 mature individuals (A. Panjabi in litt. 2017), and the species is here placed in the band 20,000-49,999 mature individuals. While this figure yields a considerable uncertainty regarding the lower band of the population estimate, in view of the large range the population size is unlikely to fall below the threshold for Vulnerable (10,000 mature individuals). Therefore, Belted Flycatcher may be listed as Least Concern under Criterion C.

Criterion D – The population size and range of this species are far too large to fall below the threshold for Vulnerable (1,000 mature individuals). Therefore, Belted Flycatcher may be listed as Least Concern under Criterion D.

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 proposed that Belted Flycatcher (Xenotriccus callizonus) be listed as Least Concern. We welcome any comments on this 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.

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

BirdLife International. 2018. Species factsheet: Xenotriccus callizonus. http://www.birdlife.org (Accessed 20/12/2018)

del Hoyo, J.; Elliott, A.; Sargatal, J. 1999. Handbook of the Birds of the World, vol. 9: Cotingas to Pipits and Wagtails. Lynx Edicions, Barcelona, Spain.

Haldeman, M. 2015. First record of Belted Flycatcher Xenotriccus callizonus from Honduras. Cotinga 37: 48-49.

Howell, S. N. G.; Webb, S. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, Oxford.

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

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.

Stattersfield, A. J.; Crosby, M. J.; Long, A. J.; Wege, D. C. 1998. Endemic bird areas of the world: priorities for bird conservation. BirdLife International, Cambridge, U.K.

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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1 Response to Archived 2019 topic: Belted Flycatcher (Xenotriccus callizonus): revise global status?

  1. Red List Team (BirdLife International) 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.

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