Archived 2020 topic: Lilacine Amazon (Amazona lilacina): revise global status?

BirdLife species factsheet for Lilacine Amazon

Lilacine Amazon is endemic to Ecuador, where it occurs along the Pacific coast from El Oro in the south to Manabí in the north. It inhabits mainly mangrove and coastal dry forest. The species roosts communally every night, preferably on mangrove islands (Berg and Angel 2006).

Until recently, there was little information regarding the population size and trends. In a detailed field survey, several roosts could be identified (Biddle et al. 2020 and references therein): Roost 1 is located on a mangrove island near Bahia de Caraquez and contains roughly 60-116 individuals, equating to 40-80 mature individuals. Roost 2 in Santa Elena contains 124-144 individuals, equating to 80-100 mature individuals. Roost 3 in El Salado Mangrove Reserve contains 32-57 individuals, equating to 20-40 mature individuals. Finally, roost 4 in Manglares Churute Ecological Reserve contains 628-729 individuals, equating to 400-490 mature individuals. Individuals from roosts 2-4 are thought to form one subpopulation, which is disconnected from the subpopulation at roost 1 (Biddle et al. 2020). Furthermore, a third subpopulation has been identified in El Oro province (Biddle et al. 2020); there is no information on the size of this subpopulation, but it is potentially small. Overall, this translates to an overall population size of at least 540-710 mature individuals. It cannot be ruled out that there are further roosts which have not been identified yet; therefore preliminarily the population size is here placed in the band 550-1,000 mature individuals. 

Lilacine Amazon is undergoing rapid population declines. The main threat is illegal hunting of both juveniles and adults for  pets; it is thought that a large proportion of the communities within the range keep Lilacine Amazons as pets (Biddle et al. 2020). Further threats are the clearance of mangroves and coastal forests for shrimp farming, cutting of firewood and agricultural expansion.

Lilacine Amazon is currently listed as Endangered under Criterion C2a(i) (BirdLife International 2020). However, new information regarding the population size and trend suggests that the species may warrant a change in Red List status. Therefore, the species will be re-assessed against all criteria:

Criterion A – The species is undergoing a decline due to high hunting pressure and the loss of suitable habitat within its range. Population declines of 60% between 2000 and 2019 were observed for the roost in El Salado Mangrove Reserve (Biddle et al. 2020). Assuming that declines are exponential, this equates to a rate of 89% decline over three generations (46.2 years; see Bird et al. 2020*). Moreover, observations of the roost in Santa Elena province suggest a decline of 59% between 2014 and 2019 (G. Blanco, F. Hiraldo and J. L. Tella per Biddle et al. 2020), which equates to a decline of c. 99% over three generations. There is no information on the rate of population change for the roosts near Bahia de Caraquez, in Manglares Churute Ecological Reserve and in El Oro province. However, we have no reason to expect significantly different population trends in these roosts; poaching pressure seems to be similarly high throughout the range, leading to rapid declines even in the population occurring in the protected El Salado Mangrove Reserve. Assuming that all known roosts are experiencing declines of similar rates (89-99% over three generations), overall the global population would be declining at c. 96-98% over three generations. Even assuming that the roosts in Bahia de Caraquez, Manglares Churute and El Oro are stable, overall rates of decline would still exceed 80% over three generations. Therefore precautionarily, Lilacine Amazon warrants listing as Critically Endangered under Criterion A4acd.

Criterion B – The newly calculated Extent of Occurrence (EOO) for this species is 28,100 km2. The maximum Area of Occupancy (AOO), calculated as a 4 km2 grid over the area of mapped range, is 7,446 km2. The EOO therefore approaches the threshold for listing as threatened under Criterion B1. However, in order to be listed as Near Threatened under this criterion, a species needs to fulfil at least two further conditions.

The species is thought to form three relatively large subpopulations (Biddle et al. 2020). It is therefore not severely fragmented sensu IUCN (IUCN Standards and Petitions Committee 2019). The most serious threats to the species are hunting for the pet trade and habitat loss, which may be the principal drivers for severe population declines in the past. Continued trapping is likely to cause rapid population declines within one generation (15.4 years) in a limited number of events. The number of locations** of occurrence is therefore likely smaller than 10, and condition a is met. Habitat degradation and loss are proceeding within the range and the population is undergoing a continuing decline (R. Biddle in litt. 2014, Biddle et al. 2020). Lilacine Amazon thus meets condition b(iii,v). There is no evidence of extreme fluctuations in the distribution range or population size, and condition c is not met. Consequently, Lilacine Amazon qualifies as Near Threatened, approaching the threshold for listing as threatened under Criterion B1ab(iii,v).

Criterion C – The global population is preliminarily estimated at 550-1,000 mature individuals. This meets the threshold for Endangered under Criterion C; however in order to be listed under this criterion further conditions must be fulfilled.

Lilacine Amazon is estimated to decline at ≥80% over three generations. Hence, sub-criterion 1 is met at the level of at least Endangered. Moreover, the species is thought to form at least three subpopulations, the largest of which may number c. 500-630 mature individuals, and sub-criterion 2a(i) is met at the level of Vulnerable. Overall, Lilacine Amazon therefore warrants listing as Endangered under Criterion C1.

Criterion D – The population size is estimated at roughly 550-1,000 mature individuals. Lilacine Amazon therefore qualifies for listing as Vulnerable under Criterion D1.

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 Lilacine Amazon (Amazona lilacina) be listed as Critically Endangered under Criterion A4acd. We welcome any comments on the proposed listing and specifically request up-to-date information on population trends in roosts outside of Santa Elena and El Salado Mangrove Reserve.

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

Berg, K. S.; Angel, R. R. 2006. Seasonal roosts of Red-lored Amazons in Ecuador provide information about population size and structure. Journal of Field Ornithology 77(2): 95–103.

Biddle, R.; Solis, I.; Cun, P.; Tollington, S.; Jones, M.; Marsden, S.; Devenish, C.; Horstman, E.; Berg, K.; Pilgrim, M. 2020. Conservation status of the recently described Ecuadorian Amazon parrot Amazona lilacina. In press.

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: Amazona lilacina. http://www.birdlife.org (Accessed 22 April 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 Categories and Criteria. Version 14. http://www.iucnredlist.org/documents/RedListGuidelines.pdf.

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9 Responses to Archived 2020 topic: Lilacine Amazon (Amazona lilacina): revise global status?

  1. Manuel Sanchez-Nivicela says:

    Dear all,

    I just reached to this forum via Twitter.

    1st. A disclaimer: the comments below are personal and are not writing on behalf of the main author and colleagues (co-authors).

    As a co-author of the recent “Red List of the Birds of Ecuador”. Just to let you know that we considered Amazona autumnalis as Endangered (EN) under A2cd+3cd+4cd; C1+2a(i). It includes a comment which is important to pointed it here: the subspecies lilacine might be a valid species, if so it can be considered as Critically Endangered (CR).

    Also, is important to remark that in Ecuador two subspecies (salvini and lilacina) inhabits the critically endangered and also IUCN listed western ecuadorian ecosystems: Western Ecuador Humid Forest, Guayaquil Flooded & Swamp Forest and Tumbes Guayaquil Seasonal Dry Forest.

    So, yes these two races or subspecies are endangered (EN) in mainland Ecuador and if lilacina is a full species, it may apply for critically endangered. But, the most important subject since 2014 for the ornithological and scientific community in Ecuador is the scientific support behind the proposal and recognition of lilacina race as full species. Which is not mentioned in the bibliography above.

    Finally, the bibliography that I used for my comment. Thanks.

    Bibliography:

    Ferrer‐Paris, JR, Zager, I, Keith, DA, et al. An ecosystem risk assessment of temperate and tropical forests of the Americas with an outlook on future conservation strategies. Conservation Letters. 2019; 12:e12623. https://doi.org/10.1111/conl.12623

    Freile, J.F. & Restall, R. (2018). Birds of Ecuador. Helm Field Guides. Bloomsbury Publishing. London. UK.

    Freile, J. F., T. Santander, G. Jiménez-Uzcátegui, L. Carrasco, D. F. Cisneros-Heredia, E. A. Guevara, M. Sánchez-Nivicela y B. A. Tinoco. (2019). Lista roja de las aves del Ecuador. Ministerio del Ambiente, Aves y Conservación, Comité Ecuatoriano de Registros Ornitológicos, Fundación Charles Darwin, Universidad del Azuay, Red Aves Ecuador y Universidad San Francisco de Quito. Quito, Ecuador.

    • Red List Team (BirdLife International) says:

      Thank you very much for your comment on the proposed status change of Lilacine Amazon and for pointing out the helpful references!
      BirdLife International recognized Amazona lilacina as a separate species in 2014, when it was split from A. autumnalis. Subspecies salvini is still included in A. autumnalis. The above assessment only refers to the form lilacina, which occurs in western and southwestern Ecuador (Manabí to El Oro).

  2. I support this proposed change.

    The northernmost population at Isla de Corazon experienced a dramatic decline from at least 80-120 birds in 2014 to none being present 2017/2018. Note that there was a single count of approx. 400 birds in 2015 here. The population at El Oro similarly declined from 22 birds in 2015/2016 to 6 birds in 2017. None had been seen on recent visits in 2018.

    The population size itself needs to be revised. Since July 2018, Fundación Jocotoco has performed a detailed monitoring at roost 2 at las balsas reserve. Roost counts are very variable, suggesting large-scale movements of individuals. Typically, the local population fluctuates between 369-1126 individuals (median 704 individuals). The largest counts were 2340 (2019) and 2578 individuals (2020).
    The strong fluctuations in roost attendance complicates inferring population declines from roost counts. Nonetheless, the data on a large scale (Isla de Corazon, El Oro Province, data from Chester Zoo) are all consistent and point towards a strong population decline that warrants listing as Critically Endangered.

    • Red List Team (BirdLife International) says:

      Thank you very much for this information. Based on high count data, the population may have numbered 2,340 individuals in 2019, which roughly equates to 1,500 mature individuals. The global population size is therefore likely considerably larger than the previous estimate of roughly 550-1,000 mature individuals. To account for uncertainties due to fluctuating roost attendance, we tentatively place the population size in the band 1,000-2,499 mature individuals. This does however not affect the listing under Criterion C, as the species still meets the threshold for Endangered under Criterion C1.

  3. Juan Freile says:

    There is no way the EOO of this species is nearly four times smaller than that of Capito squamatus. Something is not fitting. Either the EOO of Capito is overestimated or the EOO of the parrot is underestimated. It can also be explained by subtle differences on how the EOOs are calculated, but a simple ‘bird-eyes-view’ of both species EOOs suggests that they are quite similar (or at least not so disimilar…).

    • Red List Team (BirdLife International) says:

      Thank you very much for your comment. In accordance with IUCN Guidelines, the EOO is calculated as a continuous Minimum Convex Polygon around the mapped range. This results in an EOO of c.28,100 sqkm for this species.

  4. 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

  5. Red List Team (BirdLife International) says:

    Preliminary proposal

    Available evidence suggests that the population is undergoing a rapid decline across its range. We assume here that the population size is larger than thought (1,000-2,499 mature individuals), while the rate of decline is roughly equal across the range. Unless new information becomes available to suggest otherwise, the overall rate of decline is placed in the band 80-99% over three generations.

    Based on available information, our preliminary proposal for the 2020 Red List would be to list Lilacine Amazon as Critically Endangered under Criterion A4abcd.

    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 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.

  6. Red List Team (BirdLife International) says:

    Recommended categorisation to be put forward to IUCN

    The final categorisation for this species has not changed. Lilacine Amazon is recommended to be listed as Critically Endangered under Criterion A4abcd.

    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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