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Aldabra Fody Foudia aldabrana



Justification

Justification of Red List category
This species has a very small range and is threatened by introduced and native predators, habitat degradation due to droughts, and hybridisation with an invasive congener. There is no evidence for a population decline currently (instead monitoring work suggests it is increasing), and the invasive congener has been successfully eradicated, but habitat quality is likely undergoing a continuing decline which could impact the species. As such it is precautionarily listed as Endangered.

Population justification
Its population is estimated at between 2,000 and 6,000 mature individuals (Rocamora and Skerrett 2001).

Trend justification
The invasive Foudiamadagascariensis and madagascariensis aldabrana hybrids have been eradicated from Aldabra (N. Bunbury in litt. 2017). Also, despite high levels of nest failure due to predation there is currently no evidence that this predation is causing population decline. In fact, monitoring work has shown that the species increased between 2002 and 2013 (van de Crommenacker et al. 2016).

Distribution and population

Foudia aldabrana is found only on Aldabra Atoll, Seychelles.

Ecology

The species occurs in scrub, coconut Cocos nucifera groves and Casuarina woodland, as there is no forest found on Aldabra (Craig 2016).

Threats

Nest predators act across the island, and nesting success may be very low; with 48% of nestlings and 81% of eggs taken by predators such as Black Rats Rattus rattus (Safford 2013). An invasive congener, Red Fody Foudia madagascariensis, could have impacted this species as it was confirmed to have hybridised with F. aldabrana and thus could be eroding the genetic integrity of this species (van de Crommenacker et al. 2015). However, the recognition of this invasion has led to successful eradication projects to remove F. madagascariensis and madagascariensis x aldabrana hybrids from Aldabra and nearby Assumption (N. Bunbury in litt. 2017, J. van de Crommenacker in litt. 2018); and as such the species is not considered to be in continuing decline as a result of this threat (N. Bunbury in litt. 2017). Increasing drought conditions on the island however, will impact the species's habitat (Havercamp et al. 2017; J. Appoo in litt. 2018), and the sea level rise and other climate change impacts will pose additional threats.

Conservation actions

Conservation Actions Underway
Aldabra is protected as a Special Reserve under the Seychelles National Parks and Nature Conservancy Act (1981), and was designated a UNESCO World Heritage Site in 1982, a Ramsar Wetland Site of International Importance in 2009, and received a Platinum level Blue Park Award in 2019 in recognition of its strong protection. Foudia madagascariensis and all F. madagascariensis x Faldabrana hybrids have been successfully eradicated from Aldabra and Assumption (Bunbury et al., 2019; J. van de Crommenacker in litt. 2018).

Conservation Actions Proposed
Conduct surveys to obtain an up-to-date population estimate. Monitor population trends through regular surveys. Prioritise eradication of introduced predators, namely rats and cats. Ensure that F. madagascariensis does not become re-established on Aldabra, with good biosecurity measures. Conduct research into climate change impacts on Aldabra, in particular, effects on habitats from sea level rise and increasing droughts.

Acknowledgements

Text account compilers
Clark, J.

Contributors
Appoo, J., Bunbury, N., Butchart, S., Ekstrom, J., Rocamora, G., Symes, A., Westrip, J.R.S. & van de Crommenacker, J.


Recommended citation
BirdLife International (2024) Species factsheet: Foudia aldabrana. Downloaded from https://datazone.birdlife.org/species/factsheet/aldabra-fody-foudia-aldabrana on 19/03/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 19/03/2024.