Archived 2020 topic: Yellow-headed Brush-finch (Atlapetes flaviceps): revise global status?

BirdLife species factsheet for Yellow-headed Brush-finch

Yellow-headed Brush-finch (Atlapetes flaviceps) is endemic to Colombia, where it occurs on both slopes of the Central Andes and the Western Andes. It is found between 1,200 and 2,500 m. It inhabits secondary forests and forest borders as well as bushy, open areas, plantations and disturbed habitats (Renjífo et al. 2014, Jaramillo and Sharpe 2020, P. Salaman in litt. 2020). The species is threatened by the loss of habitat. It has been hypothesised that while it mainly occupies secondary vegetation, it possibly still requires the presence of forests within its range (Y. G. Molina-Martínez in Renjífo et al. 2014).  

The population has previously been estimated to number 250-999 mature individuals. However, this is now considered to be a large underestimate, as the species appears to be widespread throughout its range, in which it is recorded regularly (eBird 2020, P. Salaman in litt. 2020). Based on density estimates of congeners and the area of available habitat, the population size has been estimated to number up to 13,000 individuals; but to account for uncertainties the population size has been placed in the band 10,000-13,000 individuals (Renjífo et al. 2014). This roughly equates to 6,500-8,500 mature individuals.

Yellow-headed Brush-finch is currently listed as Endangered under Criteria B1ab(i,ii,iii,v); C2a(ii). However, new information regarding the population size and trend and the distribution range suggests that the species may warrant a change in Red List status. Therefore, it will be re-assessed against all Red List criteria:

Criterion A – The population trend has not been estimated directly. Forest loss over ten years (one generation length being estimated at 3.1 years; Bird et al. 2020*) within the range has been estimated at 11.2% (Renjífo et al. 2014). Given that the species does not depend on forest, but readily tolerates degraded and converted habitats, the rate of population decline is likely considerably lower than the rate of forest loss. The only known threat to the species is habitat loss. Therefore, while we can tentatively suspect that the species is undergoing a slow decline, the rate of decline is too low to meet the threshold for Vulnerable. As such, Yellow-headed Brush-finch may be listed as Least Concern under Criterion A.

Criterion B – The newly calculated Extent of Occurrence (EOO) for this species is 32,000 km2. This value does not meet the threshold for Vulnerable (EOO < 20,000 km2). The Area of Occupancy (AOO) has not been quantified according to the guidelines (IUCN Standards and Petitions Committee 2019). Therefore, Yellow-headed Brush-finch may be listed as Least Concern under Criterion B1.

Criterion C – The population size of Yellow-headed Brush-finch has preliminarily been estimated at c. 6,500-8,500 mature individuals. This meets the threshold for listing as threatened under Criterion C. However, to do so a species must meet further conditions.

It is suspected that the species is undergoing a slow population decline due to habitat loss. A suspected decline, however, precludes a listing as threatened under Criterion C. We have no information on the subpopulation structure, and thus the species cannot be assessed against Criterion C2. Nevertheless, applying a very conservative approach, we can suspect that the rate of decline approaches, but does not meet, 10% over ten years. Therefore, Yellow-headed Brush-finch may be listed as Near Threatened, approaching the threshold for listing as threatened under Criterion C1.

Criterion D – The newly estimated population size is too large to approach the threshold for Vulnerable (1,000 mature individuals). Therefore, Yellow-headed Brush-finch 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 suggested that Yellow-headed Brush-finch (Atlapetes flaviceps) be listed as Near Threatened, approaching the threshold for listing as threatened under Criterion C1. We welcome any comments on 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 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).

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

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.

eBird. 2020. eBird: An online database of bird distribution and abundance [web application]. eBird, Ithaca, New York. http://www.ebird.org (Accessed 11 February 2020).

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.

Jaramillo, A.; Sharpe, C. J. 2020. Yellow-headed Brush-finch (Atlapetes flaviceps). In: del Hoyo, J.; Elliot, 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/61988 (Accessed 11 February 2010).

Renjífo, L. M.; Gómez, M. F.; Velásquez-Tibatá, J.; Amaya-Villareal, A. M.; Kattan, G. H.; Amaya-Espinel, J. D.; Burbano-Girón, J. 2014. Libro rojo de aves de Colombia, Volumen I: bosques húmedos de los Andes y la costa Pacífica. Editorial Pontificia Universidad Javeriana and Instituto Alexander von Humboldt. Bogotá, Colombia.

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9 Responses to Archived 2020 topic: Yellow-headed Brush-finch (Atlapetes flaviceps): revise global status?

  1. High-quality information on this species is scarce and therefore, there is a high degree of uncertainty in any decision regarding whether or not to revise its global status. The most recent and trustworthy published review on the species’ conservation status can be found in Renjifo et al. (2014). Still, information on the species’ ecology, reproductive biology, habitat requirements, and population status is badly needed. I am not sure that a revision could be confidently carried out given the information available.

    Nonetheless, there is valuable information at the website of the Colombian NGO SELVA that I hope can be helpful in further evaluating the conservation status of Yellow-headed Bruschfinch. This information will be soon published in the scientific literature, but in the meantime, it can be accessed in the form of public reports and other documents such as conservation plans. Through its project “Identifying and conserving priority areas for the Tolima Dove (Leptotila conoveri) and Yellow-headed Brushfinch (Atlapetes flaviceps) in Colombia”, funded by American Bid Conservancy, SELVA generated a huge amount of field data that allowed to estimate the species’ AOO based on climatic niche models and occupancy models (estimated at 6880 km2). In addition, density estimates at different localities were reported for the very first time.

    All this information was summarized in a conservation plan for the species. I really hope this document is consulted and considered for taking a more informed decision. The link to the English version of the species’ conservation plan can be found at:
    http://selva.org.co/en/research-programs/threatened-species/leptotila-and-atlapetes/

    More documents (in Spanish) with more detailed information can also be found at:
    http://selva.org.co/es/areas-de-investigacion/especies-amenazadas/leptotila-y-atlapetes/

  2. Copiado de / copied from: Alex Cortés, Juan Carlos Luna, Andrea Borrero, y Juan Lazaro Toro (2020) Evaluación de especies de aves amenazadas en Colombia / Evaluation of Threatened Birds Species in Colombia. Conservación Colombiana 27: 3-31.

    “A partir de alrededor de 2010, con una mayor seguridad y seguridad en toda la gama Atlapetes flaviceps del valle del Cauca y el Magdalena (históricamente áreas con conflicto), las actividades de observación de aves y ornitológicas aumentaron significativamente. Por el contrario, hubo una explosión de avistamientos y nuevas ubicaciones para A. flaviceps al igual que con los demás endémicos de la Cordillera Central / Magdalena como Leptotila conoveri, ambos se pueden encontrar simpátricamente y tradicionalmente se consideraban raros y localizados y asignados con el status por IUCN de En Peligro. Ambas especies han tenido extensiones de rango (conformadas por fotos).

    A diferencia de Leptotila conoveri, esta especie tiene un rango más amplio ya que ocurre en ambas vertientes de la Cordillera Central, el valle central del rio Cauca e incluso muchos registros confirmados recientemente en la vertiente oriental de la Cordillera Occidental. En los últimos años, eBird registra 867 listas de verificación que reportan las especies en más de 250 ubicaciones.

    Usando registros publicados en GeoCat, el EOO es 40,253.7 km2 (Casi Amenazado) y estamos de acuerdo con Escudero-Páez & Bayly (2018) del AOO de 6,880 km2 (Casi Amenazado).

    Usando la estimación de población de Atlapetes flaviceps de 80.3 individuos / km2 (Escudero-Páez et al.2018), esto daría una estimación de población de> 550,000 individuos. Consideramos que esta densidad de población es poco probable.

    Un estudio poblacional anterior de A. flaviceps utilizó métodos extensivos e intensivos propuestos por Bibby et al (2000) en dos sitios durante cinco meses (ProAves 2004). Estas encuestas dieron densidades estimadas de 5.1-5.5 ind./km2 (intensivo) y 5.7-10.0 ind./km2 (extenso) con un promedio general de 6.5 individuos / km2. Esta estimación más conservadora daría una población total de> 45,000 individuos que creemos que es más realista.

    Al igual que Leptotila conoveri, esta especie se encuentra predominantemente en bosques secundarios y en las bordes de bosques, así como en áreas arbustivas, abiertas, jardines, cafetales y otros hábitats muy degradados. Incluso hay confirmados (fotos) de registros en las principales zonas urbanas.

    Por lo tanto, hemos revisado las especies aquí contra los criterios relevantes de la Lista Roja;

    Criterio A – Atlapetes flaviceps podría ser catalogado como Casi Amenazado

    Criterio B: los nuevos cálculos de EOO y AOO (que aumentan con el conocimiento), consideran que Atlapetes flaviceps se enumerarían como Casi Amenazados en el Criterio B1.

    Criterio C: no se percibe una disminución, por lo que se enumeraría como Preocupación Menor.

    Criterio D: no se percibe una población pequeña o restringida, por lo que se enumeraría como Preocupación Menor.

    Creemos que es seguro decir que la especie no está amenazada por la pérdida de hábitat y se ha adaptado a bosques secundario y a hábitats no boscosos, por lo que la especie amerita un cambio en el estado de la Lista Roja a Casi Amenazado.

    Referencias
    ProAves (2004) Aportes al conocimiento de la Historia Natural del Atlapetes flavíceps, Ave Endémica de Colombia. Informe de 13 páginas no publicado presentado por Arias Buenaventura Ivón, octubre de 2004.”

  3. Copiado de / copied from: Alex Cortés, Juan Carlos Luna, Andrea Borrero, y Juan Lazaro Toro (2020) Evaluación de especies de aves amenazadas en Colombia / Evaluation of Threatened Birds Species in Colombia. Conservación Colombiana 27: 3-31.

    “From around 2010 with increased security and safely across Atlapetes flaviceps range of the Cauca and Magdalena valley (historically areas with conflict), birding and ornithological activities significantly increased. Conversely, there was an explosion of sightings and new locations for A. flaviceps as with the other Central Cordillera / Magdalena valley endemic Leptotila conoveri – both can be found sympatrically and both were once considered rare and localized and assigned IUCN Endangered status. Both species have had range extensions (conformed by photos).

    Unlike Leptotila conoveri, this species has a wider range as it occurs on both slopes of the Central Cordillera, the central Cauca river valley and even many recent confirmed records on the eastern slope of the Western Cordillera. In recent years, eBird records 867 checklists recording the species at more than 250 locations.

    Using published records in GeoCat, the EOO is 40,253.7 km2 (Near Threatened) and we agree with Escudero-Páez & Bayly (2018) of the AOO of 6,880 km2 (Near Threatened).

    Using the population estimate of A. flaviceps of 80.3 individuals/km2 (Escudero-Páez et al. 2018), this would give a population estimate of >550,000 individuals. We consider this population density unlikely.

    An earlier population study of A. flaviceps used extensive and intensive methods proposed by Bibby et al (2000) at two sites for five months (ProAves 2004). These surveys gave estimated densities of 5.1-5.5 ind./km2 (intensive) and 5.7-10.0 ind./km2 (extensive) with an overall average of 6.5 individuals/km2. This more conservative estimate would give a total population of >45,000 individuals which we believe is more realistic.

    Like Leptotila conoveri this species is predominantly encountered in secondary forests and forest borders as well as bushy, open areas, gardens, coffee plantations and other heavily degraded habitats. There are also confirmed (photos) of records in major urban areas.

    Therefore, we have reviewed the species here against relevant Red List criteria;

    Criterion A – Atlapetes flaviceps would be listed as Near Threatened.

    Criterion B – The newly calculated EOO and AOO recommend Atlapetes flaviceps be listed as Near Threatened under Criterion B1.

    Criterion C –there is no perceived decline, so would be listed as Least Concern.

    Criterion D – there is no perceived small or restricted population, so would be listed as Least Concern.

    We believe it is safe to say the species is not threatened by habitat loss and has adapted to non-primary forest and non-forest habitats, so the species warrants a change in Red List status to Near Threatened.”

  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

    Based on available information that the species is not threatened by habitat loss and incurs a large population size (Fundación ProAves in litt. 2020), it is no longer tenable to list the species at a near-threatened status. Thus, our preliminary proposal for the 2020 Red List would be to list the Yellow-headed Brush-finch as Least Concern.

    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. Sara Lara says:

    Thank you for proposing the adjusted status of this species, but we note that moving it from Endangered to Least Concern instantly is too extreme. We recognize this is a marginal line case and again my team recommends that it be prudent to consider the species as Near-threatened for now.

  7. This is a very particular and interesting case needing careful evaluation. Any decision should be based on the most rigorous information available to date. SELVA has been working intensively and extensively on this species for the last five years, collecting an important amount of data and designing a conservation plan for the species based on transparent and rigorous science. Based on results from our work, we agree with the first decision made by the Red List Team of down-listing the species to Near Threatened. We do, however, strongly advise against listing the species as Least Concern.

    Our recommendation is based on the data provided in a preliminary report of our research and the conservation plan for the species, which are publicly available on our website. Data reported in those documents alongside data already reported here from other studies (Renjifo et al. 2014, Cortés et al. 2020) suggest the species should be listed as Near Threatened. A quick exercise of reviewing the species against the Red List criteria with the information at hand suggests:

    Criterion A – Forest loss over ten years within the range has been estimated at 11.2% (Renjifo et al. 2014). It is true that the species uses other habitat types and it is presumably more linked to secondary vegetation and transitional habitats, but habitat loss is still a serious threat as the species is mainly distributed throughout the most developed region of the Andes in terms of agriculture and urbanization. Of course, it is likely that, given the species’ use of mixed vegetation and transitional habitat, the population decline is not proportional to deforestation rates. Nonetheless, other processes such as the transformation of agroforestry systems to sun-grown crops or pastures, are likely having a greater impact on the species and these have not been quantified to date. Therefore, the species should be listed as Least Concern under Criterion A until more precise information on habitat loss can be generated.

    Criterion B – Cortés et al. (2020) estimate an EOO of 40.253 km2. Although none of the most recent estimations of AOO reported for the species were calculated at the scale recommended by the IUCN (4 km2; IUCN Standards and Petitions Committee 2019), they do all suggest the species’ distribution and remaining habitat is limited and highly fragmented. Our estimate of the species’ AOO corresponds to 4836 km2, estimated at 1 km2 (Escudero-Páez et al. 2018). Therefore, the species should be listed as Near Threatened under Criterion B.

    Criterion C – The population size of Yellow-headed Brush-finch has preliminarily been estimated at ~6,500-8,500 mature individuals, and assuming a slow decline, the species should be listed as Near Threatened under Criterion C. We previously reported a mean population density estimate of 80.3 ind./km2, but this is most likely an overestimation (Escudero-Paéz et al. 2018). However, we found marked spatial variation in local densities, and we believe that densities likely range between 3 to 30 ind./km2. Taking the lower estimate (as spatial variation is evident) and extrapolating to the estimated AOO, the total population would be ~14.500 individuals. Assuming that at least 50% of the population consists of reproductive individuals, the population estimate would be ~7250 individuals. As a population decline is inferred (Renjifo et al. 2014), the species should be listed as Near Threatened.

    Criterion D – Assuming that at least 50% of the population consists of reproductive individuals, the population estimate would be ~7250 individuals. Therefore, the species should be listed as Near Threatened under Criterion D.

    Criterion E – The species cannot be assessed against this criterion.

    We appreciate the opportunity given for contributing to this discussion. We do hope our contribution is carefully considered before proposing a category to the IUCN. In any case, all these analyses will be soon published in the literature and independently of whether the species is removed from the Red List or not, SELVA will recommend the species to be globally and regionally listed as Near Threatened based on all the data currently available.

  8. Having participated in SELVA’s research on the ecology and distribution of the species, I want to clarify that the opinions below reflect my own and not necessarily those of the organization.

    I also want to express my disagreement with removing the species from the Red List. Listing the species as Least Concern would seem reckless and risky. I think everyone must acknowledge that, despite the huge efforts of several researchers and organizations studying the species, we are still far from having highly detailed information on the species life history and demography, such that we can confidently assess its risk of extinction. Nonetheless, the available information all point to the species still being at imminent risk, and thus should at least be kept as Neat Threatened. I think the comment from SELVA illustrates very well how current data support the notion that the species should not be removed from the Red List.

    As the person in charge of analyzing all data published by SELVA on reports and conservation plans, I would like to add some extra facts in the hope of supporting this position even further. I would like the Red List Team to consider this extra information before making a final decision:
    • Remaining habitat for the species is less than 5000 km2, and it is severely fragmented. The fact that several conservation actions taken previously may be inappropriate for the species, because the factors affecting habitat quality for this species are still unknown. In fact, what might be valuable habitat for the species is possibly not recognized by stakeholders.
    • Although 13 areas in the Colombian National Protected Areas System and 132 private reserves overlap with the species’ distribution, they only cover ~19% of its remaining habitat. To make things worse, a recently published study (Clerici et al. 2020) has shown that deforestation in Colombian protected areas has increased during the post-conflict periods (three years after Colombia’s peace agreement). The authors studied 39 protected areas, 22 of which are located on the Andes, and found that deforestation not only increased inside the areas but also in their buffer zones. This clearly supports the idea that protection inside protected areas is not guaranteed for this and other threatened species.
    • To further expand the previous point: SELVA identified that those protected areas with higher probability of presence of the species are PNN Los Nevados, PNN Las Hermosas, and PNN Nevado del Huila. Clerici et al. (2020) report that deforestation decreased inside PNN Los Nevados and PNN Nevado del Huila, but increased at an alarming rate of 117.2% in PNN Las Hermosas. Also worrying is the fact that deforestation increased in the buffer zones of all these three protected areas.
    • SELVA’s AOO estimation, although not calculated at the recommended scale (i.e. 4 km2), is an estimation corrected for sampling effort and detectability. This provides an unprecedented, accurate estimation of the species’ remaining habitat. This estimate, as already mentioned in previous comments, also suggests that the species should be listed as Near Threatened.
    • Habitat selection and preferences are not known for the species. Despite the species frequently being observed in transitional vegetation, does not necessarily mean survival and reproductive success are higher in this habitat. This needs to be evaluated thoroughly. Unfortunately, it is fairly common to find in the literature statements such as ‘the species is adapted to agricultural areas’, and as a result, the species is assumed to be only mildly affected by deforestation. Unless evidence indicates to the contrary, anecdotal observations or descriptions of habitat associations should be interpreted cautiously and should not be taken as strong evidence for the species thriving in these habitats. Evidence for this is yet to be documented.

    References:

    Clerici, N, D Armenteras, P Kareiva, et al. Deforestation in Colombian protected areas increased during post-conflict periods (2020). Scientific Reports 10:4971. https://doi.org/10.1038/s41598-020-61861-y

  9. Red List Team (BirdLife International) says:

    Recommended categorisation to be put forward to IUCN

    Following further review, the recommended categorisation for this species has changed.

    Based on a suspected decline due to forest loss and a population size that approaches the threshold for a threatened status under Criteria C, Yellow-headed Brush-finch is recommended to be listed as Near Threatened, nearly meeting the threshold for Criterion C1.

    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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