|Scientific Name:||Acrocephalus brevipennis|
|Species Authority:||(Keulemans, 1866)|
|Red List Category & Criteria:||Endangered B1ab(i,ii,iii,iv,v) ver 3.1|
|Reviewer/s:||Butchart, S. & Taylor, J.|
|Contributor/s:||Hazevoet, C., Hering, H. & Hering, J.|
This species is confined to three small islands where, despite its adaptation to artificial habitats, its population is suspected to be declining as a result of successive droughts and an increasing human population. Its future on one island, in particular, is precarious. It is therefore classified as Endangered. The discovery of a relatively large population on Fogo, where it occurs commonly in plantations and crops, suggests that it may be less threatened than was previously feared, and if it is no longer considered to be undergoing continuing declines it may be eligible for downlisting in the future.
Acrocephalus brevipennis was once believed to be confined to Santiago, Cape Verde Islands, where it is now only locally distributed, mainly in the interior, with a few isolated sites in the south and west. It has apparently died out on Brava (no records since 1969 and formerly scarce) and was believed to have died out on São Nicolau (where it was formerly numerous). However, a previously unreported specimen collected on São Nicolau in October 1970 was discovered in the collection of the Centro de Zoologia, Lisbon, providing the impetus for a thorough search of the island (Hazevoet 1999a) and, in 1998, surveys located eight territories confined to the north-west of the island (though its long-term prospects for survival here are poor) (Hazevoet et al. 1999). In October 2004 a population was discovered on Fogo, and it has since been found to be widespread across the northern half of the island between 200-975 m, with the total population on the island conservatively estimated at 500 pairs (Hering and Hering 2005, Hering and Fuchs 2009). In addition, the species may have formerly occurred on Santo Antão (Hazevoet 1995). On Santiago, the species was recently reported from Tarrafal, far to the north of the species's known range (C.J. Hazevoet in litt. 2007). The total population was estimated at c.500 pairs in the early 1990s (Hazevoet 1995), and thought to number 1,000-1,500 birds based on its known range in 2007 (C.J. Hazevoet in litt. 2007). However the discovery of relatively large numbers on Fogo means that the total is probably considerably higher.
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The population was estimated at c.500 pairs in the early 1990s, and was thought to number 1,000-1,500 birds based on its known range in 2007 (C. J. Hazevoet in litt. 2007). However, conservative estimates of 500 pairs on Fogo mean that the total population is likely to be higher, likely numbering 1,500-2,000 mature individuals, roughly equivalent to 2,200-3,000 individuals in total.|
|Habitat and Ecology:||Its original habitat was probably scrub on mountain slopes and reedbeds in valleys (Hazevoet 1993). It is now found in a broad range of habitats up to 1000 m (J. Hering and H. Hering in litt. 2004) (though mostly lower, and formerly only thought to range to 500 m (Hazevoet 1995)). The habitats occupied at lower elevations include well-vegetated valleys (especially with patches of reeds), reedbeds, woodland, agricultural areas, and gardens in villages and small towns, notably near running water (Hazevoet 1995). In 2004, a population in the interior of Santiago was noted inhabiting Eucalyptus forest with dense, bushy undergrowth at 800-1000 m (J. Hering and H. Hering in litt. 2004). On São Nicolau, it inhabits small, dense stands of cane Arundo donax along dry riverbeds, often with shrubs and fruit trees (Hazevoet et al. 1999). On Fogo, it inhabits coffee plantations with scattered fruit trees and maize fields with coffee bushes in areas characterised by narrow, shrub-filled ravines at 490-950 m (Hering and Hering 2005, Hering and Fuchs 2009). It breeds mainly in August-November, but the breeding season may be extended in response to local rainfall (Hazevoet 1995).|
|Major Threat(s):||Habitat loss due to the combined effects of successive droughts and an increasing human population may be responsible for the population decline and restriction of its distribution on Santiago (C.J. Hazevoet in litt. 2000). This is almost certainly the cause of its decline on São Nicolau and extinction from Brava, where continuing desiccation has restricted agricultural productivity (Hazevoet 1993). In addition, disease and enviromental catastrophies are potential threats to these island populations (Hazevoet et al. 1999).|
Conservation Actions Underway
Wildlife Protection Laws, proposed in the late 1980s, have still not materialised and, as of 2007, the species still has no legal protection (C.J. Hazevoet in litt. 2007). Conservation Actions Proposed
Conduct further searches on Brava to determine whether the species is definitely extinct there (Hazevoet et al. 1999). Encourage local farmers on São Nicolau to plant stands of A. donax cane amongst their fruit trees, by means of agricultural subsidies, to increase the area of available habitat (however, this would be extremely difficult to implement) (Hazevoet et al. 1999). Carry out large-scale and long-term education and information programmes, directed at both the local authorities and general public (Hazevoet 1999b). Study the species's distribution (Hering and Hering 2005). Research its habitat requirements (Hering and Hering 2005). Investigate what threats it faces (Hering and Hering 2005). Conduct research into possible conservation actions (Hering and Hering 2005). Focus research efforts on the recently discovered population on Fogo (Hering and Hering 2005).
Hazevoet, C. J. 1993. On the history and type specimens of the Cape Verde Cane Warbler Acrocephalus brevipennis (Keulemans, 1866) (Aves, Sylviidae). Bijdragen tot de Dierkunde 62: 249-253.
Hazevoet, C. J. 1995. The birds of the Cape Verde Islands. British Ornithologists' Union, Tring, U.K.
Hazevoet, C. J. 1999. Notes on birds from the Cape Verde Islands in the collection of the Centro de Zoologia, Lisbon with comments on taxonomy and distribution. Bulletin of the British Ornithologists' Club 119: 25-31.
Hazevoet, C. J.; Monteiro, L. R.; Ratcliffe, N. 1999. Rediscovery of the Cape Verde Cane Warbler Acrocephalus brevipennis on Sao Nicolau in February 1998. Bulletin of the British Ornithologists' Club 119: 68-71.
Hering, J.; Fuchs, E. 2009. The Cape Verde Warbler: distribution, density, habitat and breeding biology on the island of Fogo. British Birds: 17-24.
Hering, J.; Hering, H. 2005. Discovery of Cape Verde Warbler Acrocephalus brevipennis on Fogo, Cape Verde Islands. Bulletin of the African Bird Club 12: 147-149.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
|Citation:||BirdLife International 2012. Acrocephalus brevipennis. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 24 May 2013.|
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