Data Zone
Justification of Red List category
This species is considered Near Threatened because it occupies a small range, within which suitable habitat is slowly lost and degraded owing to deforestation, extensive burning and over-grazing.
Population justification
The population size has not been estimated, but the species is described as 'uncommon' (Stotz et al. 1996).
Trend justification
The population is suspected to be in decline owing to habitat loss and degradation. Tree cover loss within the range is overall very low and localised (2% over ten years; Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). Nevertheless, apart from forest loss the species is additionally impacted by the degradation of its páramo habitat (N. Krabbe in litt. 2010, Fundación ProAves 2011, O. Cortes in litt. 2011), so that population declines may be higher than the rate of tree cover loss alone suggests. Tentatively, population declines are here placed in the band 1-19% over ten years.
Ramphomicron dorsale is endemic to the Sierra Nevada de Santa Marta in north-eastern Colombia.
This species occurs on the edges of humid montane forest, elfin forest and páramo, mostly from 2,000 m to the snow-line at 4,600 m (Züchner and Boesman 2020). It is thought to breed in the timberline-páramo ecotone (Fundación ProAves 2011). It appears to forage in all strata, feeding on the nectar of Ericaceae, Erythrina species, Lobeliaceae, Melastomataceae, Puya species, Rubiaceae and Salvia species, and taking insects in the air or gleaning them from leaves. It appears to undertake some seasonal altitudinal movements, moving to lower elevations in May-June (Züchner and Boesman 2020).
Extensive and regular burning and heavy livestock grazing are causing severe damage to the timberline zone in the species' range (N. Krabbe in litt. 2010, Fundación ProAves 2011). Forest clearance for agriculture is ongoing, whilst trees in some areas are unsustainably cut for firewood (N. Krabbe in litt. 2010, O. Cortes in litt. 2011). The state of páramo and the timberline-páramo ecotone in parts of the range has been described as "disastrous" (Fundación ProAves 2011). Additionally, the species may be affected by climate change (Fundación ProAves 2011).
Conservation Actions Underway
The species occurs in the Sierra Nevada de Santa Marta National Park. It is also recorded in the El Dorado ProAves Reserve, thought these may partly refer to wandering immatures (Fundación ProAves 2011). Since 2006, Fundación ProAves has been carrying out a programme to eradicate exotic pines and replace them with native trees, with the support of the local environment authority (C. Olaciregui in litt. 2012).
9-10cm. Male has very short, slightly decurved black bill; upperparts velvety black, postocular spot white, uppertail-coverts purplish-bronzy on tips; olive green gorget, rest of underparts dark grey mixed with rufous, and with green spots; tail quite long, deeply forked, purplish-black, with outer pair of rectrices broadened. Female shining green above, uppertail-coverts as in male; buffy-white below with some green spots; tail similar to male's but shorter, with outer pairs of rectrices tipped white.
Text account compilers
Hermes, C.
Contributors
Butchart, S., Cortés, O., Ekstrom, J., Krabbe, N., Olaciregui , C., Sharpe, C.J. & Taylor, J.
Recommended citation
BirdLife International (2024) Species factsheet: Black-backed Thornbill Ramphomicron dorsale. Downloaded from
https://datazone.birdlife.org/species/factsheet/black-backed-thornbill-ramphomicron-dorsale on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.