Data Zone
Justification of Red List category
This species has a very small population size and range, being confined to the islands of Mahé (including some of its satellites), Silhouette, Île du Nord, Praslin (and some of its satellites) and La Digue. The quality of its habitat is declining due principally to introduced predators, but also due to land use change towards urban development and agricultural land, causing a reduction in breeding rate and success. Despite these threats, the species population size appears to have remained stable. Due to its small population size, however, it is categorised as Vulnerable.
Population justification
Genetic analysis suggests that the global population underwent a crash some time between 1940 and the early 1970s, and at one time numbered as few as eight (3.5-22) individuals, which is compatible with claims that there were fewer than 30 birds on Mahé during the 1960s (Groombridge et al. 2009). The last comprehensive census of this species' population took place between 1975-1977, with the population size then estimated at 430 pairs (Rocamora 2013), which equates to 860 mature individuals. This was mainly split between Mahé and Silhouette (and their respective satellite islands), whose population sizes were estimated at between 380-385 pairs and 35-45 pairs, respectively, and a successfully reintroduced population of 13 individuals on Praslin in 1977.
Since then, populations on various islands have been surveyed, with varying results. Notably, the population on Praslin decreased from ten pairs in the 1980s to six pairs in 2003 (Pandolfi and Barilari 2009); whereas on other islands, populations have either not shown a marked change in size, or not been accurately determined since the last census. In 2013, a total population of at least 530 mature individuals was deduced, using a combination of survey results and records (S. Parr in litt. 1999), however this is now shown to be an error in converting 800 mature individuals down using a 2:3 ratio. All other evidence shows the population still being estimated at close to the numbers from the 1970s (e.g., Rocamora 2013), with an estimation from 2008 of 350 pairs in total (Pandolfi and Barilari 2009), including around 300 pairs on Mahé and another 40-50 pairs on Silhouette. Considering the slightly contradictory nature of these sources, the species' population size is therefore cautiously estimated at between 700 and 900 mature individuals (350 to over 400 pairs).
Trend justification
Following surveys in 2002, the Mahé population was considered stable (Millett et al. 2003). Considerable development and habitat alteration have taken place on Mahé since 2002, and it has been suggested that the population on this island has been impacted by this extensive urbanisation and is therefore unlikely to have increased since then (N. Doak in litt. 2007). However, population declines on this island have not been demonstrated, or linked to this factor.
The Praslin population has declined from around 20 pairs in the 1980s to just a few pairs in the 1990s, and six pairs in 2003 (Rocamora 1997, Pandolfi and Barilari 2009). In addition, a reduction in tree cavities on Praslin since 2003 is likely to have occurred, due to death of Sangdragon trees (Pterocarpus indicus) on the island (Rocamora 2013), inferring, combined with the housing development on Mahé and the spread of non-native predators, a reduction in habitat quality.
Although the overall population was previously inferred to have declined since the 1970s due to a smaller total population size being estimated, as this error in the quantification of the population size has now been rectified, there is no data showing such a reduction since the 1970s, despite the decline on Praslin. It is therefore suspected that the species' population is stable.
The species is endemic to the granitic islands of the Seychelles. It was historically found on most, if not all such islands (including Félicité, Long, Marianne and Curieuse, and possibly on Grande Soeur and Petite Soeur [Ferrer et al. 2019, Kemp and Kirwan 2020]). Currently, the majority of the population is found on Mahé (plus a few on its satellite islands, including Sainte Anne, Cerf, Conception and Thérèse) (Watson 2000, Pandolfi and Barilari 2009, Rocamora 2013), and also notably on Silhouette, as well as a few pairs on Ile du Nord and Praslin (the species having disappeared from the latter in 1976, and reintroduced in 1977 [Watson 1989]). There are occasional records from Curieuse and frequent observations from La Digue (N. J. Shah and S. Parr in litt. 1999, A. Skerrett in litt. 1999), the latter with some occasional evidence of possible breeding (i.e. pairs observed in their territory [Ferrer et al. 2019]). At least one pair has also been heard on Félicité (Shah et al. 1998 per Hill et al. 2002).
The species inhabits native, evergreen, upland forests, but is now found in secondary rainforest and coconut plantations, and in residential areas particularly on Mahé. It hunts mainly indigenous lizards (especially day-geckos Phelsuma spp.) (G. Rocamora in litt. 2007, Rocamora 2013), but also insects, small birds, mice, and occasionally frogs and chameleons (Watson 1981, 1992; Rocamora 2013). Breeding season is between August and November, and nesting is predominantly on cliffs above 200 m, and less successfully - probably due to predation (Watson 1992) - at lower elevations on buildings, in holes in trees and in old Common Myna Acridotheres tristis nests (Loustau-Lalanne 1962). Small territories are occupied year-round, but only one brood of 2-3 eggs is reared per year (Watson 2000).
Reduced numbers in the 1960s and 1970s may have been due to pesticide use or to peaks in commercial cinnamon cultivation and logging, which reduced upland forest to its lowest extent at this time (N. J. Shah and S. Parr in litt. 1999). The species also used to be heavily persecuted due to its association with bad luck and the belief that the species preyed on poultry (Rocamora 2013).
Nest predators, such as the Green-backed Heron Butorides striata, as well as the introduced Black Rat Rattus rattus, feral domestic cat felis catus, Barn Owl Tyto alba and Common Myna Acridotheres tristis, the latter two which can also be nest-site and food competitors, may be an ongoing threat to the Seychelles Kestrel, along with habitat degradation from human developments (Loustau-Lalanne 1962, Watson 1992, A. Skerrett in litt. 1999, Groombridge et al. 2004, Rocamora 2013, Kemp and Kirwan 2020). The species does breed on buildings and in urban areas however (N. J. Shah and S. Parr in litt. 1999, Rocamora 2013, Kemp and Kirwan 2020), but breeding success in such areas is poor, as well as in other lowland areas where development of agricultural and plantation areas have reduced the number of natural cavities and where the presence of predators is higher (Rocamora 2013). Fires, and possibly housing developments and non-native predators nearly halved the species' population on Praslin in 10 years, between the end of the 80s and end of the 90s (S. Parr in litt. 1999, Millett et al. 2003). Since 2003, the steep reduction in the number of Sang-dragon trees (Pterocarpus indicus) due to fungal disease which has caused the death of the majority of these trees is likely to have further reduced the number of suitable natural cavities present for the species (Watson 2001 per Rocamora 2013). In addition, the potential widespread use of pesticides could be a threat to the species in the future (Watson 2001 per Rocamora 2013).
Conservation Actions Underway
CITES Appendix I and II. The Morne Seychellois National Park on Mahé covers almost 25% of the island and provides a safe refuge (N. J. Shah and S. Parr in litt. 1999). The species was successfully reintroduced to Praslin in 1977 (Watson 1981). Nature Seychelles has introduced predator-proof nest boxes on Praslin and conducted awareness campaigns through the Wildlife Clubs of Seychelles (Millett et al. 2003). Studies on the species overall ecology and its limiting factors on Praslin are being undertaken (Pandolfi and Barilari 2009).
15-23 cm. Very small, rufous-and-buff falcon. Very dark rufous upperparts and even darker head, and uniform buffy, unstreaked underparts. Very agile in flight and imparts a long-tailed appearance. Immature similar to adult, but has streaked and spotted underparts and paler head. Similar spp. Much smaller than any potential vagrant falcons. Voice Sharp and rapid ki ki ki ki.
Text account compilers
Rutherford, C.A.
Contributors
Doak, N., Lucking, R., Parr, S., Rocamora, G., Shah, N.J., Skerrett, A., Symes, A. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Seychelles Kestrel Falco araeus. Downloaded from
https://datazone.birdlife.org/species/factsheet/seychelles-kestrel-falco-araeus on 24/12/2024.
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 24/12/2024.