Data Zone
Justification of Red List category
This species has a very small range, and it is thought to be dependent on oak forest habitats that are severely fragmented and declining in area and quality. Therefore the species is classified as Endangered.
Population justification
Given that the species is apparently abundant at some sites and a minimum conservative estimate of 800 individuals has been provided for the Yariguíes population (Fundación ProAves de Colombia 2011; although it has been suggested that it could be as low as 150-200, O. Cortes-Herrera in litt. 2012), it is likely that the total population lies between 1,000 and 2,499 individuals. This equates to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.
Trend justification
This species's population is suspected to be undergoing at least a slow to moderate decline owing to continued habitat loss and degradation.
Macroagelaius subalaris occurs mainly along the west slope of the East Andes in Colombia. There are historical records from south-west Cundinamarca, north to the tip of the East Andes in Norte de Santander, where it also occurred on the west slope south to the upper Zulia valley (M. Alvarez and P. G. W. Salaman in litt. 1999), and it may have occurred throughout the east slope. However, the only recent records are from Guanentá-Alto Río Fonce Fauna and Flora Sanctuary, Santander, where it has been described as common (D. Uribe per L. M. Renjifo in litt. 1994) and Serranía de los Yariguíes (Donegan et al. 2007). Its range has certainly contracted following complete deforestation in some areas. Surveys recorded the species in 22 localities (including one from which the species was historically known) from La Aguadita in Cundinamarca to Surata in Santander (Velásquez-Tibatá et al. 2005), although follow-up surveys found that many of these sites are being rapidly deforested and the species may have suffered local extinctions (O. Cortes in litt. 2007, 2011, 2012). In surveys of Serranía de los Yariguíes between 2003 and 2006, the species was recorded from three sites. At one of those sites, it was abundant; at the others it was observed less frequently (T. Donegan in litt. 2006, Donegan et al. 2007). Surveys in Yariguíes revealed high abundance in forest bordering a wetland, which may constitute an important habitat for the species (Fundación ProAves de Colombia 2011). The Yariguíes mountains probably harbour a population of at least 800 individuals, and they are regarded as the core area for the remaining global population (Fundación ProAves de Colombia 2011, Fraga and Sharpe 2016).
It inhabits subtropical and temperate forests at elevations of 1,900-3,100 m (Ridgely and Tudor 1989, Fjeldså and Krabbe 1990, Jaramillo and Burke 1999, Renjifo et al. 2002, Fraga and Sharpe 2016, T. Donegan in litt. 2012). Studies in the Cordillera Oriental have revealed that it has strongly specialised habitat requirements, being limited to humid oak (Quercus humboltii) forests (Cortes-Herrera and Hernandez-Jaramillo 2007). It is particularly abundant in forest and at forest edge near marshes, and the interface between forests and wetland areas appears to be an important habitat for the species (Fundación ProAves de Colombia 2011). Observations are invariably of small groups in the middle and upper strata, and breeding-condition birds have been collected in September (Ridgely and Tudor 1989, Fjeldså and Krabbe 1990, Jaramillo and Burke 1999). The species breeds co-operatively (Cadena et al. 2002, Fraga and Sharpe 2016), with colonies generally being located in either Quercus humboltii or Escallonia pendula trees (Cortes-Herrera and Hernandez-Jaramillo 2007) and a breeding season from May-September (Fraga and Sharpe 2016). It associates with mixed species frugivore flocks, and has been recorded in flocks of up to 30 individuals in the Yariguíes mountains (T. Donegan in litt.2006).
Since the 17th century, the west slope of the East Andes has been extensively logged, burned and cleared for conversion to agriculture (Stiles et al. 1999). This species's dependence on oaks Quercus humboltii make it highly susceptible to the effects of logging, cutting for firewood and grazing by cattle, which is thought to limit oak forest to marginal relict patches on steep and rocky areas (Cortes-Herrera and Hernandez-Jaramillo 2007). However, in some areas above 2,500 m, forest cover remains more extensive (Stiles et al. 1999). Landscape changes accelerated during the 20th century, especially after 1960, although in some areas habitat regeneration is beginning following the abandonment of marginal land (Stiles et al. 1999). Deforestation is also taking place for mining operations, principally gold mining (O. Cortes in litt. 2011). Pastures dominate the valley below Guanentá-Alto Río Fonce, but the forest is mostly intact from 1,950-2,200 m upwards. However, the lower tracts are still affected by selective logging. Landslides, following the loosening of soils after deforestation, present a threat to relict patches of forest on slopes (Cortes-Herrera and Hernandez-Jaramillo 2007).
Conservation Actions Underway
In Colombia, formerly considered Critically Endangered (Renjifo et al. 2002), but now assessed as Endangered at the national level (Renjifo et al. 2014). Guanentá-Alto Río Fonce Fauna and Flora Sanctuary protects 100 km2 of forest at 2,200-3,900 m. The highest elevations of Serranía de los Yariguíes National Park remain largely inaccessible and fall within the new national park boundaries. Reserva Páramo La Floresta probably harbours at least 100 individuals (Fundación ProAves de Colombia 2011). Also reported from Las Orquídeas, Cueva de los Guácharos and Tatamá National Parks, and from Ucumarí Regional Park (Fraga and Sharpe 2016). This species's ecology is being studied in Soatá (Cortes-Herrera and Hernandez-Jaramillo 2007).
30 cm. All black, long-tailed, icterid. Entirely dull bluish-black with chestnut wing linings and axillaries. Long, slightly rounded tail. Conical, black bill. Similar spp. Giant Cowbird Scaphidura oryzivora has longer bill, shiny plumage, neck ruff, and lacks chestnut wing linings. Voice Song is highly variable, including a variety of screeches, whistles and other noises (T. Donegan in litt. 2012, Fraga and Sharpe 2016), including a ringing tirititiuu, tirititiuu, tirititiuu with a frequency range between 8 kHz and 10 kHz (O. Cortes in litt. 2007).
Text account compilers
Butchart, S., Taylor, J., Isherwood, I., Gilroy, J., Bird, J., Sharpe, C.J., Pople, R.
Contributors
Donegan, T., Salaman, P., Alvarez, M., Renjifo, L., Cortés, O., Uribe, D.
Recommended citation
BirdLife International (2024) Species factsheet: Mountain Grackle Macroagelaius subalaris. Downloaded from
https://datazone.birdlife.org/species/factsheet/mountain-grackle-macroagelaius-subalaris 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.