Justification of Red List Category
This species has a small range, which is declining in response to continuing deforestation. Remaining habitat is small enough to qualify the species as Endangered, but it is classified as Vulnerable because there are recent records from more than five locations.
In Guatemala, the species is common in oak-alder-conifer forest above the elevation of 2,300 m, but less common in cloud forests at the same elevation. In high-elevation (2,000-2,500 m) cloud forest on the Atlantic slope, a density of 0.25 individuals/ha was estimated. A rough GIS analysis using a national vegetation cover mapping (1:50,000) based on aerial imagery from 2003 indicates that there are about 3,800 km2 of potential habitat in Guatemala. Within this area it has been reported within nine IBAs. The total population in the recently defined Guatemalan IBAs is assumed to be between 19,000 and 54,000 individuals (K. Eisermann unpubl. data). The species occurs also in disturbed forests and adjacent scrub. Data quality is poor, but most likely the total population is larger than previously estimated. It is precautionarily placed in the band 20,000-49,999 individuals.
The species is suspected to be in slow decline, owing to habitat degradation.
Ergaticus versicolor is resident in the mountains of central and extreme south-east Chiapas, Mexico and western Guatemala. Over the bulk of its range in Guatemala and on Volcán Tacaná in south-east Chiapas, it was historically very common and remains locally common (Wilson and Will 1997, Eisermann and Avendaño 2007). However, in central Chiapas, it was very rare in the mid-1980s, but became slightly more numerous at Cerro Huitepec and Rancho Nuevo from the late 1980s (Howell and Webb 1995a). There are are about 3,800 km2 of potential habitat in Guatemala and it has been recorded in nine IBAs, being most common above 2,500 m in the Tacaná-Tajumulco, Santiaguito Volcano, and Atitlán IBAs (K. Eisermann in litt. 2007). Trends in the 1990s are difficult to determine, but it is likely that the populations throughout its range have declined in response to a reduction in available habitat, and numbers in central Chiapas have not increased further (Wilson and Will 1997). The species's habitat, accounting for elevation and forest type requirements, is estimated at around 3000 km2 (Harris and Pimm 2008), and these indicate that besides having a small range, the species has experienced relatively significant historical habitat fragmentation (Schnell et al. 2013), which is likely to threaten it even further.
It inhabits humid to semi-humid pine-oak-alder, pine, cypress and forest with undisturbed understorey, as well as high-elevation scrub and cloud forest, at 1,800-3,500 m, but is most common above 2,800 m (Curson et al. 1994, Howell and Webb 1995a, K. Eisermann in litt. 2012). It can tolerate forest edge and disturbed forest with a damaged understorey (Curson et al. 1994, Howell and Webb 1995a), but this is likely to be suboptimal habitat (Curson et al. 1994).
Cloud-forest habitats in Chiapas and Guatemala have been severely fragmented. Only 400 km2 of cloud-forest remain in central Chiapas, which is fragmented into 18 widely scattered pieces (Bubb 1991), many at altitudes unsuitable for this species (Wilson and Will 1997). In Guatemala, 900 km2 of cloud-forest remains, representing 3% of the original extent (Bubb 1991), but probably only 400 km2 are occupied (J. F. Hernandez in litt. 1998). Much of the remaining habitat in Chiapas has been altered by intense human use such as coppicing for charcoal production, timber extraction, farming, flower production, animal-grazing and subsistence wood-cutting (Wilson and Will 1997) and, in Guatemala, road construction is likely to lead to further human disturbance (J. F. Hernandez in litt. 1998). Human population in Guatemala increased 35% from 1994-2002 (INE 2002) and is estimated to double between 2010 and 2050 to a total of 28 million (CEPAL 2010). Most people live in the highlands with their favourable climate and fertile soils; human pressure on the habitat of this species is going to increase (K. Eisermann in litt. 2007). The dense human population, consisting mainly of small-scale farmers, causes extensive disturbance in the forest understorey (including in protected areas) by an extensive collection of firewood, collection of leaf litter as organic fertiliser, and straying dogs, probably negatively affecting nesting success of this ground-nesting warbler. About 50% of the range in Guatemala is located within areas used or planned for exploration and opencast mining (K. Eisermann in litt. 2012). The low numbers in Chiapas in the mid-1980s may have been the result of the eruption of Volcán Chichonál in 1982, which carpeted large areas with volcanic ash (Howell and Webb 1995a).
Conservation Actions Underway
Rancho Nuevo Ecological Protection Zone has been heavily grazed and recently taken over as a military training ground. Cerro Huitepec Biological Station is very small and surrounding forest is being rapidly cleared, leading to concerns that the reserve itself may not be large enough to support a viable population (Wilson and Will 1997). Protected areas cover 33% of Guatemala, including much of the range of this species, however this protection is ineffective (K. Eisermann in litt. 2007). It is on the watch list as part of the State of North America's Birds (North American Bird Conservation Initiative 2016).
13 cm. Red warbler with pink head. Whitish-pink head and neck with red forehead and dark lores. Dark red upperparts, darker on wings and tail. Bright pinkish-red underparts. Juvenile pinkish cinnamon-brown. Darker above with blackish wings, two pinkish wing-bars and blackish tail. Voice Song is series of chips and trills. High thin tsiu call.
Text account compilers
Capper, D., Isherwood, I., Pople, R., Sharpe, C J, Khwaja, N., Westrip, J.
Eisermann, K., Hernandez, F., Schnell, J., Burne, C.
BirdLife International (2020) Species factsheet: Cardellina versicolor. Downloaded from http://www.birdlife.org on 29/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 29/09/2020.