Archived 2020 topic: Three-toed Jacamar (Jacamaralcyon tridactyla): revise global status?

BirdLife species factsheet for Three-toed Jacamar

This discussion was first published as part of the 2019 Red List update. At the time a decision regarding the status of this species was pended, but to enable potential reassessment of this species as part of the 2020 Red List update this post remains open and the date of posting has been updated.

Three-toed Jacamar (Jacamaralcyon tridactyla) occurs in small numbers at a few sites in south-eastern Brazil. It is found in the Río Paraíba valley in Rio de Janeiro state and the dry regions of east Minas Gerais at elevations between 240 and 1,100 m. While older records from Espírito Santo, São Paulo and Paraná suggest that the range has declined in the past, recent records from Minas Gerais have widened the known distribution (Machado et al. 1998, Silveira and Rocha Nobre 1998, Ribon et al. 2002, Duarte et al. 2014), and suggest that further populations may exist within this area. Overall however, Three-toed Jacamar was considered very common in the early and mid-19th century and must have suffered a very substantial decline in numbers. It is now local even in the core of its range. The total population is placed in the band 250-999 mature individuals, equating to roughly 350-1,500 individuals (BirdLife International 2019).

Three-toed Jacamar is restricted to small, isolated patches of dry forest, where it is found along forest edges, streams, roads and tracks. It is dependent on earth banks for nesting-cavities (Silveira and Rocha Nobre 1998). The species can persist in degraded areas with bushes, vines and scattered trees, where the original vegetation has been replaced, if a native understorey remains (Machado and Lamas 1996, Silveira and Rocha Nobre 1998). It is often found in heavily disturbed sites near urban areas (Tobias et al. 2019).

Although capable of surviving in some degraded woodlots, this species has undergone a major decline in the past, such that the remaining population is believed to be very small. Widespread and continuing habitat destruction are thought to be responsible for the decline in numbers and range of this species. In addition, its specialised habitat requirements ensure that it is absent from many degraded woodlots. The species is thus vulnerable to the effects of small population size, such as local extinctions and inbreeding.

Three-toed Jacamar is currently listed as Vulnerable under Criterion D1 (BirdLife International 2019), indicating a small or restricted population. However, incorporating new information on population trends and the subpopulation structure, 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 Three-toed Jacamar it assumed 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. 6,300 km2. This roughly equates to a rate of forest loss of 9.8% over three generations (18.6 years) for this species. Three-toed Jacamar seems to be able to tolerate forest fragmentation, degradation and disturbance (Machado and Lamas 1996, Silveira and Rocha Nobre 1998); however, habitat loss remains a major threat as it is thought to be responsible for drastic population declines in the past (Tobias et al. 2019). Hence, we can tentatively assume that the species is in decline, but likely at a slower rate as the forest cover; thus Three-toed Jacamar is inferred to have undergone a reduction of 1-9% over the past 18.6 years. Overall, the rate of decline is too slow to approach the threshold for Vulnerable under this criterion. Therefore, Three-toed Jacamar may be listed as Least Concern under Criterion A.

Criterion B – The Extent of Occurrence (EOO) for this species is 466,000 km2. This does not meet the threshold for Vulnerable (EOO < 20,000 km2). Therefore, Three-toed Jacamar may be listed as Least Concern under Criterion B1. The Area of Occupancy (AOO) has not been calculated and Three-toed Jacamar cannot be assessed against Criterion B2.

Criterion C – The global population is estimated to number 250-999 mature individuals. This may warrant listing the species under Criterion C, given it is considered to be declining, as long as other conditions are met. With its suspected rate of decline per Tracewski et al. (2016), it could warrant listing as Near Threatened under Criterion C1, but no higher because the population change has not been directly estimated. The species is spread out over several subpopulations, which are likely very small. Assuming that the true population size is closer to the lower end of the estimate, it is highly likely that no subpopulation consists of more than 250 mature individuals. Therefore, Three-toed Jacamar may be listed as Endangered under Criterion C2a(i).

Criterion D – The population size is estimated to number 250-999 mature individuals. Therefore, Three-toed Jacamar may be listed 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 proposed that Three-toed Jacamar (Jacamaralcyon tridactyla) be listed as Endangered under Criterion C2a(i). 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. 2019. Species factsheet: Jacamaralcyon tridactyla. http://www.birdlife.org (Accessed 13 February 2019)

Duarte, T. B. F.; de Castro Pena, J. C.; Rodrigues, M. 2014. Novo registro do cuiteláo Jacamaralcyon tridactyla (Vieillot, 1817) em fragmento florestal urbano de Belo Horizonte, Minas Gerais. Atualidades Ornitológicas 182: 24.

Machado, A. B. M.; da Fonseca, G. A. B.; Machado, R. B.; Aguiar, L. M. De S.; Lins, L. V. 1998. Livro Vermelho das espécies ameaçadas de extinção da fauna de Minas Gerais. Fundação Biodiversitas, Belo Horizonte, Brazil.

Machado, R. M.; Lamas, I. R. 1996. Avifauna associada a um relorestamento de eucalipto no município de Antônio Dias, Minas Gerais. Ararajuba 4: 15-22.

Ribon, R.; Whitney, B. M.; Pacheco, J. F. 2002. Discovery of Bahia Spintail Synallaxis cinerea in north-east Minas Gerais, Brazil, with additional records of some rare and threatened montane Atlantic Forest birds. Cotinga 17: 46-50.

Silveira, L. F.; Rocha Nobre, H. 1998. New records of Three-toed Jacamar Jacamaralcyon tridactyla in Minas Gerais, Brazil, with some notes on its biology. Cotinga: 47-51.

Tobias, J.; Züchner, T.; de Melo Júnior, T. A.; Kirwan, G. M. 2019. Three-toed Jacamar (Jacamaralcyon tridactyla). In: del Hoyo, J.; Elliott, A.; Sargatal, J.; Christie, D. A.; de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona, Spain. https://www.hbw.com/node/55941 (Accessed 13 February 2019).

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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9 Responses to Archived 2020 topic: Three-toed Jacamar (Jacamaralcyon tridactyla): 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.

  2. Claudia Hermes (BirdLife International) says:

    Recommended categorisations to be put forward to IUCN

    Based on available information, our proposal for the 2019 Red List is to pend the decision on this species and keep the discussion open until 2020, while leaving the current Red List category unchanged in the 2019 update.
    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.

  3. Luiz Gabriel Mazzoni says:

    Despite being pretty common in many areas, especially in eastern Minas Gerais, the Three-toed Jacamar (Jacamaralcyon tridactyla) is very little known. Knowledge about this species natural history and population density is scarce, and there is a lack of studies regarding quantitative analysis of extinction risk. Therefore, I endorse the proposed status change to Endangered.

  4. Red List Team (BirdLife International) says:

    This proposal was first published in 2019. Since then, the species’s range map and generation length have been revised. Since 2019, an improved method for estimating species’ generation lengths has been refined and published (Bird et al. 2020). Applying this method to Three-toed Jacamar gives a generation length of 5.3 years. The species is now acknowledged also to occur in southern Bahia. New remote-sensed information on tree cover loss within the species’s range is also now available (Global Forest Watch 2020). The new information does not affect the proposed listing. Further information is particularly requested on the species’s population size.

    The new assessment is as follows:

    Criterion A:
    Over the three generations (16 years) from 2003 to 2019, approximately 11% of tree cover with at least 30% canopy cover was lost within the species’s range (Global Forest Watch 2020). Three-toed Jacamar seems to be able to tolerate forest fragmentation, degradation and disturbance (Machado and Lamas 1996, Silveira and Rocha Nobre 1998); however, habitat loss remains a major threat as it is thought to have been responsible for drastic population declines in the past (Tobias et al. 2019). Hence, we can tentatively infer that the species is in decline, but likely at a slower rate than the forest cover; thus Three-toed Jacamar is suspected to have undergoing a reduction of 1-12% over the past three generations.

    From 2016-2019, approximately 4% of tree cover with at least 30% canopy cover was lost within the species’s range (Global Forest Watch 2020). Extrapolating over 16 years, it is assumed that up to 15% of tree cover within the species’s range will be lost within the next three generations. The species is suspected to undergo a reduction of 1-15% over the next three generations. The species is assessed as Least Concern under Criterion A.

    Criterion B:
    The Extent of Occurrence (EOO) for this species is 253,000 km2. This does not meet the threshold for Vulnerable (EOO < 20,000 km2 ). Therefore, Three-toed Jacamar may be listed as Least Concern under Criterion B1. The Area of Occupancy (AOO) has not been calculated and Three-toed Jacamar cannot be assessed against Criterion B2.

    Criterion C:
    Although it is common in some localities, especially in eastern Minas Gerais (L. G. Mazzoni in litt. 2020), it is now local even in the core of its range. Based on an assumed population density of 1.1-1.8 individuals/km2 (based on the minimum and first quartile of 11 estimates for five jacamar species), the area of tree cover with at least 30% canopy cover in 2010 within the species’s mapped range (89,200km2 ; Global Forest Watch 2020), and assuming, based on the species’s localised distribution, that 2-5% of the area of tree cover is occupied, the species’s population is suspected to be within the range 1,300 – 5,400 mature individuals. Assuming the true population size falls towards the lower end of this range, the species may meet the population threshold for Endangered under this Criterion.

    As described above, the population size is inferred to be undergoing a continuing decline. Based on the suspected rates of decline described above, it could warrant listing as Near Threatened under Criterion C1, but no higher because the population change has not been directly estimated. The species is spread out over several subpopulations, which are likely very small. Assuming that the true population size is closer to the lower end of the estimate, it is likely that no subpopulation consists of more than 250 mature individuals. Therefore, Three-toed Jacamar may be listed as Endangered under Criterion C2a(i).

    Criterion D:
    The population size is estimated to number 1,300 – 5,400 mature individuals. Therefore, Three-toed Jacamar may be listed as Near Threatened 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 proposed that Three-toed Jacamar be listed as Endangered under Criterion C2a(i). However, if further evidence suggests that the population size is more likely to be greater than 2,500 mature individuals, the species may be retained as Vulnerable, under Criterion C2a(i).

    Additional references:

    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.

    Global Forest Watch. 2020. Interactive Forest Change Mapping Tool. Available at: http://www.globalforestwatch.org/

  5. Diego Lima says:

    It inhabits gallery or semi-deciduous forest, mainly small isolated fragments; occupies degraded edges or areas with scattered shrubs and tall trees; usually close to water courses and roads. It occurs between 240-1100 m of altitude. It often occurs in locations with many lianas or highly degraded areas and close to urban areas. Sometimes unable to tolerate eucalyptus forests, even where the natural understory has been maintained (Tobias et al. 2002; Tobias et al., 2020). Likewise, it avoids intact ombrophilous forests. It seems to prefer degraded forests and tolerates a considerable degree of human alteration, but the absence of the species in apparently suitable places suggests a habitat specialization that is still poorly understood (Tobias et al. 2002; Tobias et al., 2020). It is a sedentary species and occurs in groups of two to eight individuals (Tobias et al. 2002; Tobias et al., 2020). It is dependent on gullies for its reproduction (Silveira & Nobre 1998). The species is gregarious, living in family flocks that can reach up to 20 individuals (Tobias et al., 2020), but it is very common to register flocks of about 10 birds throughout its range (Silveira & Nobre, 1999 ).

    There are no estimates based on field data for the species and therefore are not applicable for criterion C1 (IUCN Guidelines, 2019). To apply the C2 criterion, it is necessary to have an estimate collected in the field somewhere to have a sample and to be able to make an inference as allowed in the C2 criterion (IUCN Guidelines, 2019).

    Only on Wikiaves (https://www.wikiaves.com.br/wiki/cuitelao) do we have many records of the species in several municipalities in Minas Gerais, some in Bahia and Rio de Janeiro.

    For these reasons and many others established by Brazilian researchers, the species can remain as NT or perhaps LC. We are currently in the process of validating the category.

    Tobias, J.A.; Züchner, T. & Melo-Júnior, T.A. 2002. Jacamaralcyon tridactyla. p.94. In:del Hoyo et al.. Handbook of the birds of the world, Vol 7: Jacamars to Woodpeckers. Lynx Edicions. 613p.

    Wikiaves 2020. Cuitelão. Disponível em: https://www.wikiaves.com.br/wiki/cuitelao. Acessado em: 26/06/2020.

    Tobias, J., T. Züchner, TA de Melo Júnior e GM Kirwan (2020). Three-toed Jacamar (Jacamaralcyon tridactyla), versão 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, DA Christie e E. de Juana, Editores). Cornell Lab of Ornithology, Ithaca, NY, EUA. https://doi.org/10.2173/bow.thtjac1.01

    Silveira, L.F. & Nobre, H.R. 1998. New records of Three-toed Jacamar Jacamaralcyon tridactyla in Minas Gerais, Brazil, with some notes on its biology. Cotinga, 9: p.47-51.

  6. Diego Mendes says:

    Jacamaralcyon tridactyla é endêmica do Brasil, com ocorrência recente para os estados da Bahia, Rio de Janeiro e Minas Gerais, e pode ser considerado como extinta em São Paulo e no Paraná. É uma ave gregária, e os bandos frequentemente ultrapassam os dez indivíduos, chegando a existir até 20 ninhos em um único barranco. Não depende de áreas em bom estado de conservação, ocorrendo em bordas de mata, eucaliptais e áreas bastante degradadas e próximas a áreas urbanas. Embora não existam estimativas populacionais, em uma consulta à plataforma digital wikiaves, observa que esta espécie ocorre em 97 municípios em sua área de distribuição atual (BA: 5; MG: 81; RJ: 11), sem nenhum registro de extinção nestas localidades. Se um mínimo de 10 indivíduos pode ser observado em um único bando, e que cada subpopulação é composta de diversos bandos, o número de indivíduos parece ser ainda bastante alto em pelo menos 97 municípios dentro da sua área de distribuição. Além disso, a espécie é muito tolerante a ambientes alterados, o que não a qualifica dentro dos critérios de ameaça de extinção. Desta forma, J. tridactyla foi avaliada como Menos Preocupante (LC).

    Jacamaralcyon tridactyla is endemic to Brazil, with a recent occurrence in the states of Bahia, Rio de Janeiro and Minas Gerais, and can be considered as extinct in São Paulo and Paraná. It is a gregarious bird, and flocks often exceed ten individuals, reaching up to 20 nests in a single ravine. It does not depend on areas in a good state of conservation, occurring in forest, eucalyptus and very degraded areas and close to urban areas. Although there are no population estimates, in a consultation with the digital platform wikiaves, he observes that this species occurs in 97 municipalities in its current distribution area (BA: 5; MG: 81; RJ: 11), with no record of extinction in these locations. If a minimum of 10 individuals can be observed in a single flock, and that each subpopulation is made up of several flocks, the number of individuals appears to be still quite high in at least 97 municipalities within its range. In addition, the species is very tolerant of altered environments, which does not qualify within the criteria of threat of extinction. Thus, J. tridactyla was rated as Least Concern (LC).

  7. 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

  8. Red List Team (BirdLife International) says:

    Preliminary proposal

    Based on available information, our preliminary proposal for the 2020 Red List would be to list Three-toed Jacamar as Near Threatened, approaching the threshold for listing as threatened under Criteria C2a(i); D1.

    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.

  9. Red List Team (BirdLife International) says:

    Recommended categorisation to be put forward to IUCN

    The final categorisation for this species has not changed. Three-toed Jacamar is recommended to be listed as Near Threatened, approaching the threshold for listing as threatened under Criteria C2a(i); D1.

    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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