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.
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.