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Maroon Pigeon Columba thomensis
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Justification
This species is classified as Endangered, as it has a single, very small subpopulation within a very small range, and is suspected to be undergoing a rapid population decline owing to intense hunting pressure.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Taxonomic note
Columba arquatrix, C. sjostedti and C. thomensis (Sibley and Monroe 1990, 1993) are retained as separate species contra Dowsett and Forbes-Watson (1993) who include sjostedti and thomensis as subspecies of C. arquatrix.

Identification
37-40 cm. Large, very dark pigeon. Dark slate-grey head. Black centred, lanceolate neck feathers with blue-grey tips. Deep purple tinged neck, maroon mantle, slaty-black back and rump and dark brown uppertail-coverts. Deep maroon underparts, faintly speckled white. Female duller. Similar spp. São Tomé Bronze-naped Pigeon Columba malherbii is smaller and paler with metallic patches on neck and nape. Voice Deep, almost owl-like cooing.

Distribution and population
Columba thomensis is endemic to São Tomé, São Tomé e Príncipe, where its range includes Chamico in the north-west, the regions of Lagoa Amelia, Zampalma, Nova Ceilão and Bombaím in the central massif and Formoso Pequeno southwards along the valley of the rio Io Grande. In the south-west, it extends into the lowlands along the valleys of the Xufexufe and Ana Chaves rivers. In the south-east, it occurs west of Agua Izé and on the isolated peak of Maria Fernandes, north of São João dos Angolares (Atkinson et al. 1991, Christy and Clarke 1998). The species occurs at low densities, with a maximum of 18 birds observed in two 1km transects after the breeding season in a core area of high altitude forest near the Pico of São Tomé (M. B. Carvalho in litt. 2011). The global population may number considerably fewer than 1,000 mature individuals, and hunting is suspected to be causing population declines even at higher altitudes; hunting pressure may also be driving a decline in range as the species is pushed into higher, more inaccessible areas (M. B. Carvalho in litt. 2011, R. F. de Lima in litt. 2011).

Population justification
The population size has not been quantified but is probably best placed in the band 250-999 mature individuals considering its scarcity and highly restricted distribution. This equates to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend justification
A population decline of 30-49 % is suspected owing to hunting pressure: the species is large and tame and a prime target for hunters, and has disappeared or become scarce in easily accessible areas (F. Olmos, M. Carvalho & R. F. de Lima in litt. 2009, 2011).

Ecology
It is most common in primary forest above 1,000 m but also occurs in mature secondary forest, particularly coffee plantations abandoned for more than 20 years, and in lowland primary forest in the south-west and more occasionally in cultivated areas at forest edge. The diet consists primarily of fruit (Atkinson et al. 1991, Christy and Clarke 1998), and the species appears to make seasonal movements in response to fruit availability.

Threats
Historically, large areas of forest were cleared for coffee and cocoa plantations. Today, land privatisation is leading to an increase in the number of small farms and the clearance of trees. This does not currently affect primary forest, but may be a threat in the future (Gascoigne in litt. 2000). Limited areas of secondary and primary forest, particularly in the north of its range, are threatened by clearance for cultivation, timber and fuelwood-collection. Road developments along the east and west coasts are increasing access to previously remote areas (Gascoigne in litt. 2000). Construction for the country's developing oil industry, including the established idea of building 'free ports' (free economic zones) (M. Melo in litt. 2003), was seen as a potential threat to the species's habitat. However, prospecting on land was unsuccessful, and any construction is likely to be offshore (F. Olmos in litt. 2007). Hunting is the key current threat to the species, particularly in the most accessible areas of primary forest (Atkinson et al. 1991); this is the biggest pigeon on the island and it is also very tame. Significant numbers of birds may be taken at a time (eg. a single hunter was observed to kill nine birds in one hunting session) (M. B. Carvalho in litt. 2011), and the current distribution of the species is thought to be determined by hunting pressure.

Conservation Actions Underway
A new law providing for the gazetting of protected areas and the protection of threatened species (Gascoigne in litt. 2000, M. Melo in litt. 2003) has been ratified (F. Olmos in litt. 2007). Legislation for the creation of Obo National Park has also been ratified (F. Olmos in litt. 2007) and protection of primary forest as a zona ecologica has been proposed. Conservation Actions Proposed
Research its ecological requirements. Identify its key threats, including levels of hunting, in order to produce conservation recommendations. Ensure legal protection of all remaining primary forest. List it as a protected species under national law.

References
Atkinson, P.; Peet, N.; Alexander, J. 1991. The status and conservation of the endemic bird species of Sao Tomé and Príncipe, West Africa. Bird Conservation International 1: 255-282.

Christy, P.; Clarke, W. V. 1998. Guide des Oiseaux de Sao Tome et Principe. ECOFAC, Sao Tome.

Text account compilers
Ekstrom, J., Peet, N., Shutes, S., Starkey, M., Symes, A., Taylor, J.

Contributors
Carvalho, M., Gascoigne, A., Melo, M., Olmos, F., de Lima, R.

IUCN Red List evaluators
Butchart, S., Taylor, J.

Recommended citation
BirdLife International (2014) Species factsheet: Columba thomensis. Downloaded from http://www.birdlife.org on 19/04/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/04/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Maroon pigeon (Columba thomensis) 0

Key facts
Current IUCN Red List category Endangered
Family Columbidae (Doves and pigeons)
Species name author Barboza du Bocage, 1888
Population size 250-999 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 320 km2
Country endemic? Yes
Links to further information
- Additional Information on this species