Archived 2020 topic: Honduran Emerald (Amazilia luciae): revise global status?

BirdLife species factsheet for Honduran Emerald

Honduran Emerald (Amazilia luciae) is endemic to Honduras, where it occurs in arid interior valleys in the western and north-eastern parts of the country. It inhabits dry forest and scrub, mainly arid open-canopy deciduous thorn-forest (Anderson et al. 2010). The population has been estimated to number roughly 5,000-10,000 breeding pairs (Anderson 2013 in USFWS 2015), equating to 10,000-20,000 mature individuals. The species is thought to form more than five relatively large subpopulations, with up to 5,000 breeding pairs per subpopulation (Anderson 2013 in USFWS 2015, eBird 2020).

Honduran Emerald is threatened by the loss and degradation of its habitat. Thorn-forests are cleared for agricultural purposes, including cattle pastures and plantations, but also for infrastructural developments and road construction (Anderson et al. 2010, USFWS 2015, F. Rodriguez in litt. 2020). Patches of suitable habitat are fragmented and mostly small (D. L. Anderson in litt. 2010).

The species has been considered Endangered under Criterion B1ab(i,ii,iii,v); C2a(i) (BirdLife International 2020). However, new information regarding the distribution range and population size suggest that this species may warrant a change in Red List status. Therefore, we have fully reviewed the species here against all criteria.

Criterion A – The species is undergoing a moderate decline (Partners in Flight 2019). The only threat known to the species is the loss and degradation of its forest habitat. A remote sensing study found that forest within the range has been lost at a rate of 7% over ten years in the past (Tracewski et al. 2016; one generation length being 2.3 years; Bird et al. 2020*). Assuming that forest degradation is exacerbating forest loss and hence population declines are larger than forest loss alone, the species may be declining at <20% over ten years. It is therefore listed as Least Concern under Criterion A.

Criterion B – The Extent of Occurrence (EOO) for this species is 16,000 km2. The maximum Area of Occupancy (AOO), as calculated by a 4 km2 grid over the area of mapped range, is 2,320 km2. Thus, the species meets the threshold for Vulnerable under Criterion B1 (EOO < 20,000 km2). To be listed as threatened under Criterion B1 does require at least two further conditions to be met though.

The species is widespread, but patchily distributed, and can thus not be considered severely fragmented (see IUCN Standards and Petitions Committee 2019). The most severe threat is forest loss for agricultural purposes, including the creation of industrial plantations. It is conceivable that this threat can impact a large area and subsequently large part of the population at once; while the number of locations** cannot be determined exactly, it is likely that the species occurs within 6-10 locations**. Honduran Emerald thus meets subcriterion a. From the moderate rate of forest loss, we can infer that habitat availability and quality as well as the population size are in continuing decline, and subcriterion b(ii,iii,v) is met. The species is not known to undergo extreme fluctuations, and thus subcriterion c is not met. Overall, Honduran Emerald qualifies for listing as Vulnerable under Criterion B1ab(ii,iii,v).

Criterion C – The population size is estimated at 10,000-20,000 mature individuals. Assuming that the true population size is closer to the lower end of the estimate, Honduran Emerald may approach the threshold for listing as threatened under Criterion C. However, in order to do so, the species must meet further subcriteria.

From the rate of habitat loss, the species is inferred to undergo a continuing decline. It forms seven subpopulations in separate valleys, but most of them contain more than 1,000 mature individuals. Overall, the species cannot be considered approaching the threshold for listing as threatened under Criterion C, and it therefore qualifies as Least Concern under this criterion.   

Criterion D – The species’s population size and range are too large to meet the threshold for listing as threatened, and thus Honduran Emerald may be considered Least Concern under Criterion D.

Criterion E – To the best of our knowledge, there has been no quantitative analysis of extinction risk conducted for this species. Therefore, it cannot be assessed against this criterion.

Therefore, it is suggested that Honduran Emerald (Amazilia luciae) be listed as Vulnerable under Criterion B1ab(ii,iii,v). We welcome any comments to 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 the species’ Red List status. Therefore, please make sure your comments are relevant to the species’ Red List status and the information requested. 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

Anderson, D. L.; House, P.; Hyman, R. E.; Steiner, R.; Hawkins, H. R.; Thorn, S.; Rey, M. J.; Espinal, M. R.; Merineros, L. E. 2010. Rediscovery of the Honduran Emerald Amazilia luciae in western Honduras: insights on the distribution, ecology and conservation of a ‘Critically Endangered’ hummingbird. Bird Conservation International 20(3): 255-262.

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: Amazilia luciae. http://www.birdlife.org (Accessed 17 March 2020).

eBird. 2020. eBird: An online database of bird distribution and abundance [web application]. eBird, Ithaca, New York. http://www.ebird.org (Accessed 17 March 2020).

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.

Partners in Flight. 2019. Avian Conservation Assessment Database, version 2019. http://pif.birdconservancy.org/ACAD.

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.

USFWS. 2015. Endangered and threatened wildlife and plants; listing the Honduran Emerald (Amazilia luciae). Federal Register 80(145): 45086-45097.

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4 Responses to Archived 2020 topic: Honduran Emerald (Amazilia luciae): 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 8.8% of tree cover with 75% 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. Honduran Emerald is recommended to be listed as Vulnerable under B1ab(ii,iii,v).

    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.

Comments are closed.