Please note that this topic was edited on 3rd June 2020 to include the evidence provided by the newly-released Global Forest Change dataset (Hansen et al. 2013) of tree cover loss up to 2019. The recommended category has been changed as a result.
Diademed Amazon (Amazona diadema) is endemic to Brazil, where it has been recorded in the lower río Negro and adjacent northern bank of río Amazon, in Amazonas and NW Pará states, and recently on the lower río Madeira (A. Lees in litt. 2020, WikiAves 2020). The species inhabits a variety of lowland forest habitats, including the edges of evergreen forest, as well as modified areas containing scattered trees or plantations (del Hoyo et al. 1997, del Hoyo et al. 2016). The primary threat to this species is deforestation in the Amazon Basin, as land is cleared for cattle ranching, soy production and the expansion of the road network, coupled with its susceptibility to trapping (Soares-Filho et al. 2006, Bird et al. 2011).
Diademed Amazon is currently listed as Endangered under Criterion A4 because a model of future deforestation in the Amazon basin projected that the species would lose 49-55% of suitable habitat within its distribution over 37 years from 2002 (Soares-Filho et al. 2006, Bird et al. 2011). Given its susceptibility to trapping, the species was suspected to decline by 50-79% over this period (BirdLife International 2020). The species is now being reassessed using more up-to-date data on deforestation:
Criterion A – Four percent of tree cover with at least 50% canopy was lost within the species’s range between 2001 and 2019 (Global Forest Watch 2020). Assuming a similar rate over the past three generations, this would equate to a reduction of around 8% over three generations (35 years; Bird et al. 2020)*. Rates of deforestation in the Brazilian Amazon were higher before the mid-2000s, so the average rate of forest loss over the past 35 years may have been greater than that inferred from tree cover loss since 2000, but the area where the species is found has not been subjected to high levels of deforestation and retained 89% tree cover in 2010 (Global Forest Watch 2020). The species is found in modified habitats so it may not have declined at the same rate as tree cover. However, the species is assumed to experience some trapping pressure, so is suspected to have declined by 5-15% over the past three generations.
Although the rate of clear-cut deforestation in the Brazilian Amazon rose significantly from 2018-2019 (INPE 2019), higher-resolution data on forest loss within this species’s range does not show the same trend (Global Forest Watch 2020). Between 2016 and 2019, approximately 1.4% of tree cover was lost within the species’s range within four years (Global Forest Watch 2020). If this rate were to continue, on average, over the next three generations (35 years), this would amount to a total loss of 12% of forest. The species is suspected to undergo a population reduction of 10-19% over the three generations from 2016, and over the next three generations. Diademed Amazon may therefore qualify as Least Concern under Criterion A.
Criterion B – The Extent of Occurrence (EOO) is inferred to be 289,000 km2, based on a minimum convex polygon around the species’s mapped range, including the newly-discovered range in the lower river Madeira (A. Lees in litt. 2020, WikiAves 2020). This does not approach the threshold for listing the species as threatened, and Diademed Amazon is assessed as Least Concern under Criterion B1.
The Area of Occupancy (AOO) has not been quantified, but is unlikely to meet or approach the threshold (2,000 km2) for listing the species as threatened under Criterion B2; thus Diademed Amazon is considered Least Concern under Criterion B2.
Criterion C – The population size has not previously been estimated and no survey data are available. Based on density estimates of congeners (first quartile and median: 2 and 3 individuals per km2), the area of tree cover with at least 50% canopy cover within the species’s mapped range in 2020 (91,460 km2; Global Forest Watch 2020) and assuming 25-40% of forest within the species’s range is occupied, the population size is tentatively suspected to fall within the range 46,000 – 110,000 individuals, roughly equating to 30,000 – 74,000 mature individuals. This does not approach the threshold for listing the species as threatened under Criterion C. Diademed Amazon is therefore assessed as Least Concern under this criterion.
Criterion D – Based on the population estimates described above, the population size does not meet or approach the threshold for Vulnerable under Criterion D. The species is therefore assessed as Least Concern under this criterion.
Criterion E – To the best of our knowledge no quantitative assessment of the probability of extinction has been conducted for this species, and so it cannot be assessed against this criterion.
Based on the above assessment, it is proposed to list the Diademed Amazon (Amazona diadema) as Least Concern. However, should evidence arise that indicates that the rate of population decline is faster than suggested here, the category may be revised. We welcome any comments to the proposed listing. Information is particularly requested on rates of deforestation within the species’s range, and the level of trapping the species is subject to.
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’s Red List status. Therefore, please make sure your comments are about the proposed listing. 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.
Bird, J. P., Martin, R., Akçakaya, H. R., Gilroy, J., Burfield, I. J., Garnett, S. G., Symes, A., Taylor, J., Şekercioğlu, Ç. H. and Butchart, S. H. M. 2020. Generation lengths of the world’s birds and their implications for extinction risk. Conservation Biology online first view.
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: doi: 10.1111/j.1472-4642.2011.00843.x.
BirdLife International (2020) Species factsheet: Amazona diadema.
del Hoyo, J., Collar, N., Kirwan, G.M. and Sharpe, C.J. 2016. Diademed Amazon (Amazona diadema). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. and de Juana, E. (eds), Handbook of the Birds of the World Alive, Lynx Edicions, Barcelona.
del Hoyo, J.; Elliott, A.; Sargatal, J. 1997. Handbook of the Birds of the World, Vol. 4: Sandgrouse to Cuckoos. Lynx Edicions, Barcelona, Spain.
Global Forest Watch. 2020. Interactive Forest Change Mapping Tool. Available at: http://www.globalforestwatch.org/.
Hansen, M. C., P. V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S. V. Stehman, S. J. Goetz, T. R. Loveland, A. Kommareddy, A. Egorov, L. Chini, C. O. Justice, and J. R. G. Townshend. 2013. “High-Resolution Global Maps of 21st-Century Forest Cover Change.” Science 342 (15 November): 850–53. Data available on-line from: http://earthenginepartners.appspot.com/science-2013-global-forest.
INPE. 2019. A estimativa da taxa de desmatamento por corte raso para a Amazônia Legal em 2019 é de 9.762 km². São José dos Campos-SP Available at: http://www.inpe.br/noticias/noticia.php?Cod_Noticia=5294. (Accessed: 25 March 2020).
Soares-Filho B.S., Nepstad D.C., Curran L.M., Coutinho Cerqueira G., Alexandrino R., Azevedo Ramos C., Voll E., McDonald A., Lefebvre P. and Schlesinger P. 2006. Modelling conservation in the Amazon basin. Nature 440: 520-523.
WikiAves. 2019. Papagaio-diadema. Available at: http://www.wikiaves.com.br/wiki/papagaio-diadema. (Accessed: 30 March 2020).