Data Zone
Justification of Red List category
This species is assessed as Vulnerable because it is restricted to a single island and outlying islet and has a small population. Even though habitat degradation is ongoing slowly the species shows some resilience and there is no evidence of declines.
Population justification
The species is described as the least common of the three resident landbirds on Fernando de Noronha (Hosner 2020, see also eBird 2023). Point counts along almost the entire trail system in 2009 found 354 individuals (Mestre et al. 2016). Based on these surveys it is assumed that the total population numbers at least 1,000 individuals (Mestre et al. 2016, ICMBio 2018, L. Mestre in litt. 2020). Consequently, a very preliminary estimate is of 700-c.1,000 mature individuals.
Trend justification
It is hypothesised that the species used to be more widespread prior to anthropogenic changes in habitat (Olson 1994, Mestre et al. 2016). However, as all large trees on the island were cut with human colonisation several centuries ago, the species seems to show considerable resilience to habitat conversion (Olson 1994). While there are indications that the population had declined in the past this reduction appears to be historical, and the population may currently well be stable.
Elaenia ridleyana is confined to the Atlantic archipelago of Fernando de Noronha, Brazil, where it is known from the main island and Ilha Rata, the largest associated islet (Olson 1994).
It inhabits scrub, woodland and gardens. The diet is insects and small fruit, particularly those of the endemic tree Ficus noronhae (Antas et al. 1990). Reproduction occurs throughout the year, with a peak during March to May (L. Mestre in litt. 2020). The nest is constructed with the tendrils of Cucurbitaceae and a few twigs, and located in the bare branches of a Burra, Erythrina or cashew-nut tree (Oren 1982).
Its absence from cleared areas suggests that this species was presumably historically more widespread, as the island was reportedly covered in forest when discovered in 1503 (Olson 1994). All large trees have long since been cut and all remaining vegetation on the island is secondary (Olson 1994). However, this appears to have had little effect on the viability of the population, even though the species' preference for and higher abundance in well-conserved areas and natural vegetation suggests that there may be some sensitivity to human disturbance (Mestre et al. 2016). Habitat loss and degradation is however still ongoing slowly; the main driver being touristic infrastructure developments (Mestre et al. 2016). Cats and rats were introduced to the island in the 19th century, though likely even much earlier (A. Schulz Neto in litt. 1999, Russell et al. 2018); their continued presence on the island suggests that possible predation is unlikely to impact on Noronha Elaenia.
Conservation Actions Underway
Large parts of the range are protected within Fernando de Noronha Marine National Park. Monitoring and environmental education activities are carried out as part of the Endemic Bird Project of Fernando de Noronha (C. B. L. Licarião per L. Mestre in litt. 2020). Sterilisation of feral cats is ongoing (C. B. L. Licarião per L. Mestre in litt. 2020).
Conservation Actions Proposed
Survey to provide an updated and accurate estimate of the population size. Research the species' habitat requirements and tolerance of habitat conversion and degradation. Investigate potential impacts of introduced species on the population trend. Carefully monitor the population trend. Effectively protect areas of suitable habitat. Continue to raise awareness for the species.
17 cm. Dull grey-brown flycatcher. Paler yellow to whitish below. Bold whitish wing-bars. Similar spp. Resembles allopatric Large Elaenia E. spectabilis. Smaller Noronha Vireo Vireo gracilirostris has no wing-bars. Voice Various vocalisations including short, strong thiu-thiu and monotonous üuu, üuu whistles.
Text account compilers
Hermes, C.
Contributors
Benstead, P., Capper, D., Harding, M., Marks, T., Mestre, L., Pople, R., Schulz Neto, A., Sharpe, C.J., Symes, A. & Williams, R.
Recommended citation
BirdLife International (2024) Species factsheet: Noronha Elaenia Elaenia ridleyana. Downloaded from
https://datazone.birdlife.org/species/factsheet/noronha-elaenia-elaenia-ridleyana 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.