Justification of Red List Category
This species occurs in a very small range, within which suitable habitat is threatened by logging of forests and degradation of grasslands. Caused by these threats, it is suspected that the population is in slow decline. Nevertheless, as the population cannot be considered severely fragmented or restricted to few locations, it is evaluated as Near Threatened.
Based on population densities of congeners (S. stilesi and rodriguezi) the population size has been estimated at 4,965-23,170 individuals (Renjifo et al. 2014 and references therein). This equates to 3,300-15,500 mature individuals.The population structure has not been assessed, but based on observational records (eBird 2021) it is conceivable that the species forms several small subpopulations.
The species's population is suspected to be in decline owing to the loss, fragmentation and degradation of suitable habitats primarily through continued deforestation and intermittent fires. Habitat loss has been low in the past; it is estimated that between 2000 and 2010 the species lost a total of 1.9% of its habitat (Renjifo et al. 2014). Tree cover loss over the past ten years has been similarly low, amounting to 1% over this period (Global Forest Watch 2021). In addition to forest loss, the species is also affected by the degradation of páramo grasslands (Renjifo et al. 2014). Assuming that the rate of population decline is roughly equivalent to the rate of habitat loss and degradation, the population decline is tentatively placed in the band 1-9% over ten years.
The species occurs in the Western Andes of Colombia, where it ranges from Páramo de Paramillo in the north to Páramo de Frontino, Farallones de Citara and Tatamá in the south.
Scytalopus canus was first described by Chapman in 1915 (Krabbe and Cadena 2010), but was subsumed into S. magellanicus until a taxonomic study was published in 1997 (Krabbe and Schulenberg 1997). Subsequently S. opacus was treated as a subspecies of S. canus owing to a lack of recorded vocalisations for S. canus; however, an analysis of vocal and genetic differences supports their treatment as separate species (Krabbe and Cadena 2010).
The species inhabits vegetation at the timberline in the transition zone between páramo grasslands and forest, including scrub, stunted trees and Polylepis woodland (Krabbe and Cadena 2010; Fundación ProAves 2011; Krabbe et al. 2020). It may locally descend to the higher zones of humid forest, particularly where Chusquea bamboo is present (Renjifo et al. 2014). It forages on moss-covered trunks, along branches in dense scrub and on the ground for small invertebrates and berries (del Hoyo et al. 2003).
Deforestation continues to affect the timberline ecotone in the species's range (Fundación ProAves 2011; Krabbe et al. 2020). Páramo zones are locally affected by the expansion of cattle ranching (Renjifo et al. 2014). Its habitats are also threatened by fires. In January 2010, a fire accidentally started by hikers destroyed an area of suitable habitat at Páramo de Frontino. Its ability to adapt to regenerating forest (Fundación ProAves in litt. 2011) may limit the impacts of these threats. As a high elevation species it is potentially threatened by the effects of climate change, which may influence the frequency and severity of fires and droughts and could alter the extent of suitable habitats (Fundación ProAves 2011).
Conservation Actions Underway
The species occurs in several protected areas, including Colibrí del Sol Bird Reserve, Urrao-Abriaquí Reserve and Las Orquídeas National Park (Renjifo et al. 2014). Paramillo National Park supposedly protects Páramo de Paramillo; however in reality it is ineffective, with no attempts to control ongoing high deforestation rates ongoing inside the park (Fundación ProAves 2011).
Conservation Actions Proposed
Carry out surveys to obtain an exact estimate. Search for the species at areas of páramo near known sites. Monitor population trends. Monitor the extent and condition of suitable habitat. Improve the protection of Paramillo National Park. Increase the area of protected habitat at Páramo de Frontino.
10.5 cm. A fairly small, dark tapaculo (del Hoyo et al. 2003). Adult males are uniform grey above and deep grey below; iris dark brown; upper mandible blackish, lower dark grey; base of bill often paler. Tarsus dark grey-brown to blackish on outside, pale to dark grey-brown on the inside. Female apparently not known with certainty, but probably paler with brown on upperparts or flanks (del Hoyo et al. 2003). Similar spp Blackish Tapaculo S. latrans is very similar in appearance but has very different vocalisations. Other dark tapaculos in Colombia have distinct brown or reddish colouration to the lower flanks. Voice Song a 4- to 12-second trill or churring, with 7-11 notes per second, accelerating, with falling pitch. Note that S. opacus has a more rapid trilling song with lower more constant pitch and constant or decelerating pace (Krabbe and Cadena 2010).
Text account compilers
Cadena, C., Fundación ProAves, Sharpe, C.J. & Taylor, J.
BirdLife International (2023) Species factsheet: Scytalopus canus. Downloaded from http://www.birdlife.org on 27/03/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/03/2023.