Santa Marta Foliage-gleaner (Clibarnornis rufipectus): revise global status?

BirdLife species factsheet for Santa Marta Foliage-gleaner

Santa Marta Foliage-gleaner is endemic to Colombia, where it occurs in the Sierra Nevada de Santa Marta. It inhabits a variety of habitats, from humid primary forest to secondary forest with dense undergrowth, scrub and shade-grown coffee plantations, at altitudes of 600-1,875 m (Krabbe 2008, Botero-Delgadillo et al. 2015, Renjifo et al. 2016). The population density was found to vary by habitat and altitude, with densities being highest in forests at 1,000-1,500 m (Botero-Delgadillo et al. 2015). Based on density estimates, the population size was calculated at 9,300-13,100 mature individuals, though the true population size may be closer to the lower end of the estimate (Botero-Delgadillo et al. 2015, E. Botero-Delgadillo in litt. 2020).

Despite its tolerance of low levels of habitat conversion, Santa Marta Foliage-gleaner is threatened by the loss and fragmentation of its habitat, and it was found to be absent in sun-grown coffee plantations and in small secondary-growth patches surrounded by open areas (Botero-Delgadillo et al. 2015, Renjifo et al. 2016). Large parts of the original vegetation in the Sierra Nevada de Santa Marta has already been lost, and subsequent population declines are projected to be ongoing (Renjifo et al. 2016).

Santa Marta Foliage-gleaner is currently listed as Near Threatened, approaching the threshold for listing as threatened under Criterion B1ab(ii,iii) (BirdLife International 2020). However, new information regarding the distribution range as well as 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 population decline as suitable habitat within its range are disappearing. Over 60% of the original vegetation within the range has already been lost in the past. Recently, deforestation rates seem to have slowed down, amounting to up to 15% per decade between 2001 and 2010 (Renjifo et al. 2016, see also Global Forest Watch 2020). Taking the impacts of habitat loss and fragmentation into account, the species has been projected to decline by 20-29% over the next ten years (Renjifo et al. 2016). Santa Marta Foliage-gleaner therefore qualifies for listing as Near Threatened, approaching the threshold for listing as threatened under Criterion A3c+4c.

Criterion B – The newly calculated Extent of Occurrence (EOO) for this species is 4,400 km2. The maximum Area of Occupancy (AOO), calculated as a 4 km2 grid over the area of mapped range, is 2,808 km2. The EOO therefore meets the threshold for listing as Endangered under Criterion B1. However, in order to be listed as threatened under this criterion, a species needs to fulfil at least two further conditions.

Due to its mobility and ability to disperse through secondary habitats, the species is tentatively thought to form one subpopulation (Botergo-Delgadillo et al. 2015, E. Botero-Delgadillo in litt. 2020). It is therefore not severely fragmented sensu IUCN (IUCN Standards and Petitions Committee 2019). The most serious threats to the species is the loss and fragmentation of its habitat, particularly in the lower altitudinal zones. However, given that large parts of its range contain intact habitat and that the species is able to tolerate low levels of habitat conversion, habitat loss is unlikely to cause extraordinary population declines within one generation (2.4 years; see Bird et al. 2020*) in a limited number of events. The number of locations** of occurrence is therefore likely considerably larger than 10, and condition a is not met. Habitat degradation and loss are proceeding within the range, and the species is projected to undergo a moderate decline over the next ten years. Santa Marta Foliage-gleaner 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, although the EOO is small, Santa Marta Foliage-gleaner does not fulfil sufficient conditions to qualify as threatened under this criterion. It is therefore listed as Near Threatened, approaching the threshold for listing as threatened under Criterion B1b(iii,v).

Criterion C – The global population is estimated at 9,300-13,100 mature individuals, and it has been hypothesised that the true population size is closer to the lower end of the estimate (Botero-Delgadillo et al. 2015, E. Botero-Delgadillo in litt. 2020). This meets the threshold for Vulnerable under Criterion C; however in order to be listed under this criterion further conditions must be fulfilled.

The species is projected to decline by 20-29% over the next ten years (Renjifo et al. 2016). Furthermore, even though genetic data to assess the population structure are lacking, it is assumed that all individuals belong to the same subpopulation (Botero-Delgadillo et al. 2015, E. Botero-Delgadillo in litt. 2020). Santa Marta Foliage-gleaner therefore qualifies as Vulnerable under Criterion C1+2a(ii).

Criterion D – The population size and range are too large to warrant listing as threatened under Criterion D and therefore, the species is considered Least Concern under this criterion.

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 Santa Marta Foliage-gleaner (Clibanornis rufipectus) be listed as Vulnerable under Criterion C1+2a(ii). 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).

**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

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: Clibanornis rufipectus. http://www.birdlife.org (Accessed 15 April 2020).

Botero-Delgadillo, E.; Bayly, N.; Gómez, C.; Pulgarín-R., P. C.; Páez, C. A. 2015. An assessment of the distribution, population size and conservation status of the Santa Marta Foliage-gleaner Automolus rufipectus: a Sierra Nevada de Santa Marta endemic. Bird Conservation International 25: 451-465.

Global Forest Watch. 2020. Interactive Forest Change Mapping Tool. http://www.globalforestwatch.org (Accessed 15 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.

Renjifo, L. M.; Amaya-Villarreal, A. M.; Burbano-Giron, J.; Velasquez-Tibata, J. 2016. Libro rojo de aves de Colombia, Volumen II: Ecosistemas abiertos, secos, insulares, acuaticos continentales, marinos, tierras altas del Darien y Sierra Nevada de Santa Marta y bosques humedos del centro, norte y oriente del pais. Editorial Pontificia Universidad Javeriana e Instituto Alexander von Humboldt. Bogota, Colombia.

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6 Responses to Santa Marta Foliage-gleaner (Clibarnornis rufipectus): 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 2.4% of tree cover with >30% 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. Based on the recorded population densities in 2020 species the population size is preliminarily estimated to number between 10 a 15 individuals (4 kilometers) on the road to Reserve El Dorado. Given that the species has been described as fairly common even so the true population size is likely is unknow

  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.

    “Estamos de acuerdo en que Clibanornis rufipectus debería figurar como Vulnerable en el Criterio C1 + 2a (ii).

    Clibarnornis rufipectus está restringido a las laderas boscosas subtropicales húmedas del norte y noroeste de Sierra Nevada de Santa Marta, principalmente observado y escuchado desde arriba de 800 m hasta 1,800 m.

    Esta es una especie de bosque primario que es tolerante a niveles moderados de degradación del hábitat y puede ocurrir en bosques secundarios con matorrales densos y en ocasiones en cafetales descuidada de sombrío, pero no en cafetales a libre exposición o en plantaciones limpias [bien mantenidas] de café de sombra.

    El extremo inferior de la estimación del tamaño de la población en el hábitat adecuado en Botero-Delgadillo (2015) es más realista (9.300 – 13.100 individuos maduros), ya que la especie es poco común.

    La Sierra Nevada se eleva tan precipitadamente desde su base hasta la línea de nieve que el rango de elevación del bosque subtropical para C. rufipectus es un área muy restringida que no exceda un EOO de 2.600 km2. Si bien algunas áreas de bosques subtropicales permanecen en la ladera norte de Sierra Nevada, están cada vez más colonizadas y deforestadas.

    Según Global Forest Watch (2020), en el rango de 2.600 km2 de C. rufipectus en la Sierra Nevada de Santa Marta ha habido un aumento en las pérdidas de cobertura arbórea del 7,6% (18.400 ha) desde 2000. Sin embargo, un tercio del bosque la pérdida de cobertura ha tenido lugar en los últimos cuatro años desde 2016 (5,900 ha).

    En relación con el área de distribución de Clibarnornis rufipectus, el polígono corresponde a 306.000 has (IUCN 2020). De 2001 a 2019, el área perdió 15.000 ha de cobertura arbórea, lo que equivale a una disminución del 4.9% en la cubierta arbórea. Sin embargo, en los últimos 4 años después el proceso de paz, se ha observado que la tasa de deforestación en el área de presencia de C. rufipectus, ha aumentado a razón de 3,5% a casi el 5 % esto ha representado una tasa de pérdida de 1.671 has bosque/año (Global Forest Watch 2020), si esta relación continuara en 10 años el área de distribución de la especie probablemente habrá perdido casi 34.000 has.

    Con este panorama las plantaciones de café se seguirán expandiendo en toda la región, así como también el incremento de la oferta y demanda de fincas vacacionales que talan los bosques para proporcionar hospedajes turísticos, jardines y mejores vistas del paisaje para el visitante. De esta manera, es un hecho la pérdida de bosques y la degradación acelerada de los hábitats adecuados para la subsistencia de la especie, y en este sentido las poblaciones de C. rufipectus seguramente seguirán disminuyendo.

    ProAves recomienda que Clibarnornis rufipectus sea listada como Vulnerable en los Criterios Criterio C1 + 2a (ii).”

  4. 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.

    “We concur that Clibanornis rufipectus should be listed as Vulnerable under Criterion C1+2a(ii).

    Clibarnornis rufipectus is restricted to the humid subtropical forested slopes of NW Sierra Nevada de Santa Marta primarily observed and heard from above 800 m up to 1,800 m.

    This is mostly a primary forest species that is tolerant to moderate levels of habitat degradation and can occur in secondary forests with dense thickets and sometimes in overgrown shade coffee plantations, but not in full sun-exposure or clean [well maintained] shade coffee plantations.

    The lower end of the size estimate of the population in the appropriate habitat in Botero-Delgadillo (2015) is more realistic (9,300 – 13,100 mature individuals), since the species is rare.

    The Sierra Nevada rises so precipitously from its base to the snowline that the subtropical forest elevational range for C. rufipectus is a restricted area that does not exceed an EOO of 2,600 km2. While some areas of subtropical forests remain on the northern slope of the Sierra Nevada, they are increasing colonized and cleared.

    According to Global Forest Watch (2020), across the 2,600 km2 range for C. rufipectus in the Sierra Nevada de Santa Marta there has been an increase in tree cover losses of 7.6% (18,400 ha) since 2000. However, one third of forest cover loss has taken place in just the last four years since 2016 (5,900 has).

    In relation to the distribution of C. rufipectus according to IUCN (2020), the polygon corresponds to 306,000 ha. From 2001 to 2019, the area lost 15,000 ha of tree cover, which is equivalent to a decrease of 4.9% in tree cover. However, in the last 4 years after the peace process, it has been observed that the deforestation rate in the area of presence of C. rufipectus has increased at a rate of 3.5% to almost 5% this has represented a loss rate of 1,671 ha forest / year (Global Forest Watch 2020), if this relationship continued in 10 years the range of the species will probably have lost almost 34,000 has.

    With this panorama, coffee plantations will continue to expand throughout the region, as well as the increase in the supply and demand of vacation farms that cut forests to provide lodgings, gardens and better views of the landscape for visitors. In this way, the loss of forests and the accelerated degradation of suitable habitats for the subsistence of the species is a fact, and in this sense the populations of C. rufipectus will surely continue to decrease.

    ProAves recommends that Clibanornis rufipectus be listed as Vulnerable under Criteria C1 + 2a (ii).”

  5. 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

  6. Red List Team (BirdLife International) says:

    Preliminary proposal

    Based on available information, our preliminary proposal for the 2020 Red List would be to list Santa Marta Foliage-gleaner as Vulnerable under Criterion C1+2a(ii).

    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.

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