Data Zone
Justification of Red List category
This species has an extremely small range confined to mixed tree-fern forest on one small island, where the presence of invasive animal and plant species presents a considerable risk to the very small population. The species is therefore listed as Critically Endangered.
Population justification
The population was estimated at c. 500 individuals in the mid-1980s (Brooke 1988). Surveys in 2002 and 2011 placed the population at c.140 individuals (I. Hahn, P. Hodum and M. Wainstein in litt. 2003, Hahn et al. 2006, I. Hahn in litt. 2012). However, surveys using a different methodology during 2006-2007 estimated a population similar to the c. 500 individuals counted 20 years previously (Tomasevic et al. 2010). As there is currently no evidence of declines or increases, the population is here tentatively placed in the band 140-500 individuals, which roughly equates to 90-330 mature individuals. An exact quantification of the current population is however urgently required.
Trend justification
The species underwent a rapid decline between the mid-1980s and early 2000s, but seems to have stabilised at around 140-500 individuals since.
This species is endemic to Alejandro Selkirk (Más Afuera) in the Juan Fernández Islands, Chile. It is only found in undisturbed areas of the highlands.
This gleaning insectivore is found primarily in Dicksonia externa fern forest, and has a strong association with canelo Drimys confertifolia, an endemic species of tree. It also regularly occurs in Lophosauria quadripinnata dominated slopes in the upper elevations of the island (P. Hodum in litt. 2012). It is most common along stream courses where luxuriant Dicksonia grows to a height of 5 m. There are records at elevations as low as 600 m, but it occurs primarily above 800 m (Hahn and Römer 1996). It is typically skulking and found in pairs or family groups (P. Hodum in litt. 2012).
The species has a minimum territory size of 4 ha per pair in optimal habitat, although most are larger due to poorer habitat quality; nests are placed in natural and man-made cavities, particularly in small natural holes in steep rocks (Hahn et al. 2004, 2010, 2011; P. Hodum in litt. 2007, 2008). Nesting occurs from late November to early February and fledglings have been noted in January and February (P. Hodum in litt. 2006, 2012; Hahn et al. 2011).
It is probably secure as long as mature tracts of the ferns Dicksonia and Lophosauria remain intact, but a large proportion of natural vegetation on the island has been degraded and fragmented by goat-trampling, fire and timber-cutting (I. Hahn in litt. 2004, Hahn et al. 2004, Anon. 2007). The species does not occur in degraded and disturbed areas (Remsen Jr. et al. 2020). Significantly, it is absent from the lowlands, where the forest understorey has already been destroyed.
Introduced mammalian predators are thought to have a significant impact on the population, with rats (Rattus spp.) and possibly mice (Mus musculus) impacting on brood survival, and feral cats impacting on juvenile and adult survival (Hahn and Römer 2002, Tomasevic et al. 2010, Oikonos undated). Invasive plants (notably Chilean Guava Ugni molinae, Elmleaf Blackberry Rubus ulmifolius and Maqui Aristotelia chilensis) further degrade available habitat (Oikonos undated). An unusual increase of native Red-backed Hawk Geranoaetus polyosoma during the last decades, as illegal hunting of this species by fishermen has ceased and the hawk population has benefited from preying upon introduced mammals, may have contributed modestly to any recent declines, with several cases noted of hawks preying on rayaditos (I. Hahn in litt. 2004, Hahn et al. 2004).
Conservation Actions Underway
The Juan Fernández Islands were designated as a national park in 1935 (protected from 1967) and a UNESCO Biosphere Reserve in 1977. The islands have been nominated for World Heritage listing.
Sheep were removed from the island in 1983 (Carboneras 1992). A goat control programme was undertaken from 1998-2003 but has only continued on a sporadic basis since (P. Hodum in litt. 2007, 2008). Invasive plants are eradicated with help from local communities (Oikonos undated). The Chilean government began a habitat restoration programme in 1997 (J. C. Torres-Mura in litt. 1999), but that effort concluded in 2003. Nest boxes, designed to stop non-native rodents from entering, were installed in a variety of habitats and are being used by the species (P. Hodum in litt. 2006, Oikonos undated).
Educational materials including posters and community talks have been produced by Juan Fernández Islands Conservancy and Oikonos (P. Hodum in litt. 2007, 2008, 2012).
Conservation Actions Proposed
Produce an updated estimate of the population size. Study the species to gain a better understanding of its reproductive biology. Establish a continuous monitoring scheme of the species' population and its reproductive success.
Continue the eradication of introduced taxa, in particular rats and mice, feral cats, goats and invasive plant species. Continue habitat restoration efforts by establishing canelo Drimys confertifolia seedlings and increasing the area covered by canelo trees. Continue to supply nest boxes to increase the availability of nesting sites. Continue educational programmes to increase awareness of the species, both in the islands and more broadly to the general public.
16 cm. Small, distinctive furnariid. Generally dull greyish-buff. Dusky brown crown and auriculars. Dull buff throat and eyebrow. Blackish wings with two cinnamon-buff bars across remiges. Black tail with pale rufous central feathers and broad tip to outer rectrices. Slender bill. Voice Often delivers churring trrrt call.
Text account compilers
Hermes, C.
Contributors
Ashpole, J, Bird, J., Brooke, M., Capper, D., Hahn, I., Harding, M., Hodum, P., Khwaja, N., Pople, R., Sharpe, C.J., Symes, A., Torres-Mura, J.C., Wainstein, M., Wallace, G. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Masafuera Rayadito Aphrastura masafuerae. Downloaded from
https://datazone.birdlife.org/species/factsheet/masafuera-rayadito-aphrastura-masafuerae on 23/12/2024.
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 23/12/2024.