Data Zone
Justification of Red List category
This species is only known from a restricted area. It occurs at a low density and has highly specific habitat requirements, so it probably has a very small population. It is feared that habitat degradation is ongoing slowly within its very small range, so the population is suspected to be declining. For these reasons it is listed as Endangered.
Population justification
The population size is likely very small (M. Juiña in litt. 2020). At the type locality, the population density was estimated at 6-7.5 individuals/km2 (per Greeney 2020). Assuming that the species is occurring at a similar density across its known range (covering an area of 120 km2), the global population is estimated at up to 720-900 individuals. This roughly equates to 480-600 mature individuals.
The subpopulation structure has not been formally assessed. Despite some juvenile dispersal, the species is otherwise sedentary and territorial (Greeney 2020); as such, the spatial spread of observational records and fragmentation of the range suggests that the species forms four separate subpopulations. Extrapolating the sizes of the four subpopulations based on the observed density of 6-7.5 individuals/km2 indicates that the largest subpopulation may number c. 390-490 individuals, equating to c. 260-325 mature individuals, while the other three subpopulations may number around 110-140 individuals each, equating to c. 70-90 mature individuals.
Trend justification
Forests within the range are largely continuous (Freile et al. 2010). Nevertheless, parts of the range are threatened by logging, forest degradation and gold mining (Greeney 2020). Precautionarily, the population is suspected to undergo a decline, the rate of which unlikely exceeds 10% over three generations.
Grallaria ridgelyi was discovered in 1997 in southern Ecuador. Although its range has been estimated as Tapichalaca Biological Reserve environs, east and south-east to the Cordillera de Tzunantza and southern Cordillera del Condor, south-west to the río Isimanchi, and possibly further north and south (Krabbe et al. 1999), it is currently known only from Tapichalaca Biological Reserve (formerly Quebrada Honda Reserve), adjacent parts of Podocarpus National Park, Cerro Toledo, San Luis, rio Blanco and the Cordillera del Condor, Peru (Heinz et al. 2005; O'Neill 2006). Initially, three specimens were taken and c.12 pairs observed (Koeppel 1998), but two further specimens have since been collected in both Ecuador and Peru and additional birds noted (Krabbe et al. 1999; O'Neill 2006). Very little of the habitat between the known sites is high enough for the species and therefore unlikely to be occupied (R. S. Ridgely in litt. 2007).
The species inhabits the undergrowth of wet, montane evergreen forest, with bryophyte-clad, generally low trees and bamboo, within the subtropical zone, at 2,300-2,680 m (Krabbe et al. 1999). It prefers natural forest and areas close to steep quebradas and little streams, which maintain a high humidity throughout the year (M. Juiña in litt. 2020). The birds seem to require the existence of a stream (which can be quite small, but must remain moist), and spend a large majority of their time very close to this (R. S. Ridgely in litt. 2007, 2012). Radio telemetry indicates that birds have a large (20-40 hectares) home range (R. S. Ridgely in litt. 2007; Juiña and Bonaccorso 2013). Evidence suggests that it breeds mainly between October and May (M. Juiña in litt. 2020) and a nest is described by Greeney and Juiña (2010). Stomach contents comprised invertebrate remains, including insects (beetles and ants) and their larvae, worms and millipedes (Krabbe et al. 1999; M. Juiña in litt. 2020).
The Tapichalaca Biological Reserve is situated near a road that is frequently used for commercial transport, and a road-widening project in 2009-2010 probably affected two territories here (R. S. Ridgely in litt. 2012). Much of the range is threatened by logging and gold mining, including areas within Podocarpus National Park (Koeppel 1998). Forest degradation is ongoing at a slow rate throughout the region.
Conservation Actions Underway
The type-locality is within Tapichalaca Biological Reserve, a 35 km2 area purchased and managed following the species's discovery (Krabbe et al. 1999; Sornoza Molina 2000; Ridgely and Greenfield 2001). It also occurs in the adjacent Podocarpus National Park (Krabbe et al. 1999), but only along the southern border, where threats from human settlement and gold miners are most concentrated (Snyder et al. 2000). Overall, large tracts of forest are still continuous within the range (Freile et al. 2010). A revised management plan for the area has been devised, and a public awareness campaign highlighting the park's importance has been initiated (Snyder et al. 2000).
22 cm. Remarkably plumaged, large antpitta. Black crown. Dark grey nape and much of face, except bold white moustachial. Grey-brown upperparts, with more rusty-tinged wings and dark-streaked mantle and scapulars. Whitish grey underparts. Grey legs and all-black, deep-based bill. Reddish irides. Voice Song consists of 6-10 or more notes separated by intervals of 1-2 seconds, distinctly lower pitched than songs of its closest relatives. Softer, two-noted ho-co call.
Text account compilers
Hermes, C.
Contributors
Aucca Chutas, C., Benstead, P., Capper, D., Díaz, D., Juiña, M., Krabbe, N., Mahood, S., Marks, T., Pople, R., Ridgely, R.S., Schaefer, H.M., Sharpe, C.J., Simpson, N., Sornoza, F., Stuart, T., Valqui, T. & Waliczky, Z.
Recommended citation
BirdLife International (2024) Species factsheet: Jocotoco Antpitta Grallaria ridgelyi. Downloaded from
https://datazone.birdlife.org/species/factsheet/jocotoco-antpitta-grallaria-ridgelyi 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.