|Scientific Name:||Copsychus sechellarum Newton, 1865|
|Taxonomic Source(s):||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.|
|Identification information:||18-21 cm. Large, thrush-like, black-and-white robin. Adult entirely black with glossy, dark blue sheen, except for clear white bar on upper half of wing. Juvenile, duller plumage and grey edges to white wing-bar. Similar spp. In flight, possibly confused with Common Myna Acridotheres tristis which has smaller, white wing-bars and white in tail visible in flight, and brown on back. Voice Very varied with some hoarse calls and jumbled, melodic song.|
|Red List Category & Criteria:||Endangered D ver 3.1|
|Reviewer(s):||Butchart, S. & Symes, A.|
|Contributor(s):||Bristol, R., Gerlach, J., Lucking, R., Millett, J., Parr, S., Rocamora, G., Shah, N., Skerrett, A., Samways, M.J., Gane, J. & López-Sepulcre, A.|
|Facilitator/Compiler(s):||Benstead, P., Ekstrom, J., Harding, M., Pilgrim, J., Shutes, S., Symes, A., Taylor, J., Warren, B. & Westrip, J.|
This species is listed as Endangered because its population is extremely small, although it is increasing following intensive conservation efforts including translocations, and has exceeded 50 mature individuals (the threshold for Critically Endangered) since 2000.
|Previously published Red List assessments:|
|Range Description:||Copsychus sechellarum was orginally present on eight (possibly 13) islands (Millett and Parr (undated; in Bristol et al. 2005)) in the Seychelles, but in 1965, only 12-15 birds remained on Frégate (Gaymer et al. 1969). A small introduced population on Alphonse survived until about 1960 (Edwards undated). The Frégate population numbered c.40 birds in 1977/78, however by 1981 this had been reduced to c.20 birds, and numbers remained around this level until the 1990s (Edwards undated). In 1994, following the advent of a recovery programme, the population had increased to 48 (attributable to an increase in birth rate and first-year survival [Norris and McCulloch 2003]). , with two birds translocated to Aride. In 2000, following further translocations, the population reached 86 (comprising 46 on Frégate, 23 on Cousin, 15 on Cousine and two on Aride) (Millett et al. 1999; Millet and Shah 2001). The population has continued to increase since 2000, with a total of 110 individuals in 2003 (R. Bristol in litt. 2003), 136 individuals in 2004 (including 90 mature individuals) (R. Bristol in litt. 2004), and an estimated 150 in 2005 (R. Bristol in litt. 2005). In 2006, the population had increased to 178 birds (including 82 on Frégate, 46 on Cousin, 32 on Cousine and 18 on Aride) (N. Shah in litt. 2006, López-Sepulcre et al. 2008). Three of the four populations are now at carrying capacity, with only small population increases anticipated as habitat continues to improve (R. Bristol in litt. 2005). However, one bird emigrated from Aride to Denis Island in August 2004 (R. Bristol in litt. 2005; J. Millett in litt. 2004), demonstrating that the species is capable of dispersing to peripheral cays. In 2008 20 birds were translocated to Denis and the population has been on the increase since (A. López-Sepulcre in litt. 2016). As of 2015, the total population was of 283 birds on five islands (137 on Fégate, 46 on Cousin, 32 on Cousine, 10 on Aride and 58 on Denis [Burt et. al 2016]). Two of the five islands (Cousin and Cousine) have remained stable for the last decade, and two (Frégate and Denis) show continuing increases. However, one of them (Aride) has experienced a steep decline, standing currently at 9 individuals, of which only one is a fertile female (G. Rocamora in litt. to A. López-Sepulcre 2016).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The population in 2015 was 283 birds (including 137 on Frégate, 58 on Denis, 46 on Cousin, 32 on Cousine, and 10 on Aride) (Burt et al. 2016). This number is roughly equivalent to 190 mature individuals.|
Trend Justification: The total population was 86 birds in 2000 (Millet and Shah 2001), this had increased to 178 in 2006 (N. Shah in litt. 2005), indicating a population increase of more than 100% over six years, owing to intensive conservation efforts, and as of 2015 the population was 283 (Burt et al. 2016).
|Current Population Trend:||Increasing|
|Habitat and Ecology:||Its original habitat was mature coastal forest which provided a rich feeding ground in the leaf-litter (McCulloch (1996). Today it forages in mature woodland on central plateaus, plantations and vegetable gardens. The preferred habitat structure includes a tall, closed canopy with a sparse understorey and ground vegetation but abundant leaf litter (Millett and Parr (undated; in Bristol et al. 2005)). It feeds predominantly on small soil invertebrates (c.95% of food items, Bristol et al. 2005) mostly cockroaches, including the alien Indian cockroach (Millett and Parr undated; in Bristol et al. 2005; M. Samways in litt. 2016), but fruit, fish dropped by tree-nesting terns (Le Maitre 2002; Bristol et al. 2005), vertebrates, including skinks and geckos, eggs and human food scraps are also taken (Bristol et al. 2005). Territories are 1-2.5 ha, depending on the habitat quality, and are held by dominant breeding pairs, which may tolerate the presence of related or unrelated subordinate birds. Conflict for reproductive dominance has been shown to decrease territory productivity (López-Sepulcre et al. 2008) and is particularly strong when differences in habitat quality are large (López-Sepulcre et al. 2010). The species has a low reproductive rate with an average of 1.1 chicks per pair annually and reproductive maturity is gained at c.12 months (Watson et al. 1992). Incubation takes 17-18 days (Bristol et al. 2005). Nests are sited in holes in large trees or in the crowns of coconut palms. Reintroduced populations have suffered from a male-biased sex ratio, largely because of the higher mortality of adult females, the cause of which is unclear (Gerlach and Le Maitre 2001). The juveniles of this long-lived species take between four weeks and three months after fledging to reach independence (Bristol et al. 2005). The oldest recorded individual was a male who died on Cousine Island on 28 September 2000 at just under 16 years old (Gane and Burt 2016). The mean annual survival rate over an 18-year period was 78% and decreases in annual survival is related to increasing population size which is a likely consequence of increased competition for territories and food (Gane and Burt 2016). |
|Continuing decline in area, extent and/or quality of habitat:||No|
|Generation Length (years):||3.6|
|Movement patterns:||Not a Migrant|
|Major Threat(s):||On Frégate, predation by cats may have caused the initial decline, but the population failed to recover after their eradication in the 1980s (McCulloch 1996, Edwards undated, Bristol et al. 2005). The introduced population on Alphonse was wiped out in c.1960 (Edwards undated) following the introduction of cats in the 1950s (Bristol et al. 2005). Predation by rats and habitat loss are also implicated in the species's decline (Edwards undated). Declines in the quality and quantity of habitat on Frégate have been linked with the commercial production of crops such as banana and cocoplum (Edwards undated). Factors compounding the species's recovery include: other introduced predators and competitors (Barn Owl Tyto alba (A. Skerrett in litt. 1999, Bristol et al. 2005), Common Myna Acridotheres tristis (Mee 1996b, Edwards undated, Bristol et al. 2005), black rat Rattus rattus (Bristol et al. 2005), and brown rat Rattus norvegicus (R. Lucking in litt. 1999; Bristol et al. 2005)), the encroachment of dense cover and invasive plants following the abandonment of plantations (McCulloch 1996, Bristol et al. 2005), lack of abundant food close to nest-sites (Edwards undated), pesticides (used to control insects in hotels and houses) (Parr and Shah 1999, Edwards undated), accidental mortality due to the species's inquisitive behaviour, and, on Aride, infection by pathogenic bacteria (Lucking et al. 1997). Pesticides may be ingested when birds consume dead cockroaches, and this may have been causing the higher rates of adult mortality that have been noted near human habitation (Edwards undated). Following the complete eradication of cats and rats on Frégate, the species was thought to be limited by its native predators, including Wright's skink Trachylepis wrightii and a snake species, which are nest predators and probably responsible for almost all egg and small chick losses (Edwards undated). There is evidence that fewer invertebrates are found amongst alien leaf litter than under native trees (Bristol et al. 2005). Future risks potentially include predator reintroduction and sea-level change (J. Millett in litt. 2004). Introduced fungal diseases may have a detrimental effect on forest habitats, but may result in a net habitat gain as affected areas can be replanted with native species (the introduction of a vascular wilt disease to Frégate has not impacted the population there) (J. Millett in litt. 2004; J. Gerlach in litt. 2005). On Cousine the ecosystem is potentially threatened by an invasive ant and its mutualistic honeydew producing insects as they can produce dieback of Pisonia grandis (Gaiger et al. 2011).|
Conservation Actions Underway
A scheme to eradicate feral cats was initiated on Frégate in the early 1980s, however, despite its success, the population of C. sechellarum stayed critically low for the remainder of the decade (Edwards undated). A recovery programme was initiated in 1990 (S. Parr and N. J. Shah in litt. 1999) and, since 1998, has been managed locally. Meetings of the Seychelles Magpie Robin Recovery Team happen twice a year on Praslin, involving stakeholders in reviewing and planning conservation efforts (Millet and Shah 2001); this has helped domestic financing, with the islands of Cousine, Cousin and Aride all funding their own monitoring work (Parr et al. 1999). Translocations have taken place to four small, predator-free islands (Parr 1998a; Parr et al. 1999), habitat restoration activities are underway on several islands, but it may be several years before they are suitable for further translocations (R. Bristol in litt. 2005). Nesting success has been boosted by habitat creation, supplementary feeding (Njoroge et al. 2001), nest defence, provision of nest boxes, and reduction of A. tristis. Supplementary feeding was first initiated in the early 1990s to increase reproductive rate and the survival of young birds, however as the populations grew and habitat improved, it was phased out on Cousin in the 1990s and on Frégate and Cousine in 2001-2002 (Bristol et al. 2005). By 2007, supplementary feeding was still taking place on Aride where the population was introduced in 2002 (G. Rocamora in litt. 2007). Nest boxes are adapted to prevent predation by native predators. The populations of T. alba on Cousin, Cousine and Aride are controlled, however they are supplemented by immigration from Praslin (Bristol et al. 2005). A. tristis has been eradicated on Aride and Cousin, leaving a controlled population on Frégate and a small population on Cousine. Brown rats were eliminated from Frégate in 2000. The use of insecticides (particularly containing organophosphates) on all islands where the species resides has been banned or is subject to a restricted use policy (Bristol et al. 2005). Research has been conducted to establish alternatives for indoor insect control that are not toxic to birds (Edwards undated) with pyrethrum-based insecticides and hydroponics systems now preferred (Bristol et al. 2005). Genetic studies have been carried out to investigate inbreeding (R. Lucking in litt. 1999), and research on factors affecting territory quality, with implications for habitat management, has been undertaken (Parr and Shah 1999). An integrated pest management programme is being implemented on Frégate (S. Parr and N. J. Shah in litt. 1999). Fieldwork in summer 2006 included a full population survey, the ringing of unringed birds and replacement of old rings (Bristol and Ward 2006). In addition, biometric measurements and blood samples were taken for molecular sexing and records. It was noted on Fregate in 2006 that habitat had continued to improve owing to management (Bristol and Ward 2006). In 2008 20 birds were transferred to Denis Island and there were several successful breeding attempts within six months of the release (N. Shah in litt. 2006, Anon. 2009). North Island should be considered for future transfers since rats and cats have now been eradicated and forest habitats are being actively restored (G. Rocamora in litt. 2007). A successful project to control invasive ants from Cousine has taken place, and once they had been controlled natural enemies started to control their honeydew producing mutualists, thus tackling the threat to the ecosystem (Gaiger et al. 2012, Gaiger and Samways 2013, Gaiger et al. 2013).
Conservation Actions Proposed
Identify at least three new islands for future translocations, eradicate introduced mammals and restore natural habitat (R. Lucking in litt. 1999; Shah and Parr 1998). Establish self-sustaining breeding populations on at least seven islands by 2012 (G. Rocamora in litt. 2007). Resolve problems restricting establishment of this species on Aride (R. Lucking in litt. 1999). Continue development of local expertise, ownership and management of the recovery programme (N. Shah in litt. 2000). Develop a veterinary holding operation for emergency situations (Parr and Shah 1999). Translocate birds to North Island (G. Rocamora in litt. 2007).
|Amended reason:||Map revised.|
|Citation:||BirdLife International. 2017. Copsychus sechellarum (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22709978A111061160.Downloaded on 17 August 2018.|
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