Data Zone
Justification of Red List category
This species has a small range within which its small population is occurs patchily within a small total occupied area. Available habitat continues to be slowly lost and degraded primarily due to conversion for agriculture, timber extraction and the impacts of livestock on forest structure and regeneration. While the total population size is estimated to potentially fall below the threatened threshold the largest subpopulation exceeds one thousand mature individuals, and despite the small range there cannot be few locations in respect of the main threats. Accordingly Grey-headed Antbird is assessed as Near Threatened.
Population justification
The species is described as rare, uncommon and local (Schulenberg et al. 2007, Freile and Restall 2018). In Peru, it was found to occur at a density of 0.43 pairs per ha with an average territory size of 0.47 ha (Kikuchi 2009). In 2022, a total of 2,120-2,710 km2 of forest with at least 75% canopy cover remained within the known and probable range (Global Forest Watch 2024, using Hansen et al. [2013] data and methods disclosed therein). With the range mapped to contiguous areas with occurrence records to reflect the observed rarity and patchy occupancy of apparently suitable habitat (F. Angulo in litt. 2024, M. Sanchez-Nivicela in litt. 2024, N. Kaare Krabbe in litt. 2024) the area of forest with at least 75% canopy cover present in 2022 was 890-981 km2 (Global Forest Watch 2024, using Hansen et al. [2013] data and methods disclosed therein), or alternatively the Area of Habitat (AoH) is estimated at 1,485 km2 at 300 m resolution using the sRedList platform (sRedList 2024). Assuming that the population density observed in Peru is representative for the entire range, and further assuming that only 10% of forest area are occupied to account for the species' rarity, a minimum global population may number roughly 7,700-8,400 mature individuals. Using the AoH value gives an estimate of 12,700 mature individuals (sRedList 2024). While the species is clearly restricted, much of the remaining forest between the records has not been adequately surveyed and the species plausibly occupies 10% of the wider suitable forest area in areas mapped as probable occurrence. which gives a value of between 18,000 and 23,000 mature individuals as a maximum population size. Hence the population size is estimated at between 8,000-18,000 mature individuals.
Based on the spatial distribution of records (eBird 2023, GBIF.org 2023) and assumed low dispersal abilities of the species there may be at least three separate subpopulations, and possibly up to eight. The largest, using assumptions as above, would comprise considerably more than a thousand mature individuals (estimated at 7,400 if dispersal is limited to 4 km [sRedList 2024]), though small isolated subpopulations may not be sustainable (noting that coverage has been low in the areas between the recorded presences and connectivity may be greater than precautionarily assumed).
Trend justification
The population trend has not been investigated, but declines are suspected on the basis of ongoing loss and degradation of habitat. Tree cover within the range is lost at a rate of 2% over ten years (Global Forest Watch 2023, using Hansen et al. [2013] data and methods disclosed therein). This value however does not account for additional impacts of degradation of the understory. Given the species' dependence on particular microhabitat associated with intact forests, population declines are suspected to be steeper than the rate of tree cover loss alone. They are therefore here precautionarily placed in the band 5-15% over ten years.
Ampelornis griseiceps occurs on the Pacific slope of the Andes in south-west Ecuador (El Oro and Loja) and north-west Peru (Tumbes, Piura, Lambayeque and Cajamarca) (Schulenberg et al. 2007, Angulo 2009, Freile and Restall 2018). It has a restricted range with an extent of occurrence of 16,900 km2, within which there are approximately eight separate parts of the range with recorded presence (eBird 2023, GBIF.org 2023). Each of these may represent separate subpopulations but given their spatial distribution it is likely at least five of these lie within the dispersal distance of the species. Occupancy is patchy as it is generally associated with dense areas of Chusquea bamboo. Using a 2 x 2 km grid over the mapped area with confirmed presence records and contiguous adjacent suitable habitat, a maximum area of occupancy (AOO) is 3,156 km2 (sRedList 2024). A precautionary minimum AOO is 316 km2 if only 10% of available habitat is actually occupied, reflecting the species' apparent exacting microhabitat requirements (Zimmer and Isler 2020).
Forest cover is being lost at a rate of c. 2% per decade from within this restricted range, hence there is an estimated continuing decline in the area, extent and quality of habitat.
This poorly-known antbird is confined to Chusquea bamboo and dense undergrowth in semi-deciduous moist forest, cloud-forest and, occasionally, deciduous forest, at 600-2,900 m. In Peru there are records in disturbed and secondary forests (F. Angulo in litt. 2012). It keeps to dense vegetation, rarely above 4 m, where it tends to forage in pairs or family groups, often within mixed-species understorey flocks. The diet is unrecorded, but it probably takes invertebrates. Its breeding ecology is virtually unknown, although two juveniles were taken in June, suggesting that it nests during the wet season, in January-May. This is supported by observations that it is much more vocal in the early wet season.
The principal threats to the species are habitat destruction and degradation, mainly through livestock damage to forest understorey, agricultural expansion and wood extraction (F. Angulo in litt. 2012, SERFOR 2018). Apart from degrading forest understory, trampling and grazing by goats and cattle prevent tree regeneration in closed-canopy forest (Dodson and Gentry 1991, Jiggins et al. 1999). At higher elevations within its range, habitat destruction is less of a threat, but logging, agricultural conversion and plantations are destroying and degrading forest (Dodson and Gentry 1991). However, this species appears to thrive in bamboo-dominated second-growth that grows back once pasture is abandoned (Ridgely and Greenfield 2001).
Conservation Actions Underway
The species occurs in several protected areas across its range, including Tumbes National Reserve in Peru. It is listed as Vulnerable at the national level in Peru (SERFOR 2018) and as Endangered in Ecuador (Freile et al. 2019).
Conservation Actions Proposed
Survey for the species in suitable habitat within and adjacent to its known range. Research the association with bamboo and what importance this has to the species' conservation. Monitor the population trend. Protect additional forest within its range. Restore degraded areas.
13.5-14 cm. Principally grey-and-brown antbird with noticeable wing and tail spots. Grey head and neck, with brown back and large white dorsal patch. Black wing-coverts with bold white spotting. Black breast and throat, but otherwise grey underparts. Sexes similar, although female has paler head and neck, reduced dorsal patch, wing and tail spotting, and lacks black on underparts. Voice Song a simple, short, descending trill. Call a nasal, querulous squee-squirt.
Text account compilers
Hermes, C., Martin, R.
Contributors
Angulo Pratolongo, F., Bird, J., Butchart, S., Freile, J., Harding, M., Isherwood, I., Sharpe, C.J., Stuart, T., Symes, A., Williams, R., Krabbe, N. & Sánchez-Nivicela, M.
Recommended citation
BirdLife International (2024) Species factsheet: Grey-headed Antbird Ampelornis griseiceps. Downloaded from
https://datazone.birdlife.org/species/factsheet/grey-headed-antbird-ampelornis-griseiceps on 23/11/2024.
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 23/11/2024.