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Sao Tome Green-pigeon Treron sanctithomae

Justification
This species is classified as Vulnerable because it is confined to a single island on which high hunting pressure (both for subsistence and for trade) is suspected to be a driving rapid decline in its single small population.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Taxonomic note
Treron australis, T. calvus, T. sanctithomae and T. pembaensis (Sibley and Monroe 1990, 1993) are retained as species contra Dowsett and Forbes-Watson (1993) who include calvus, sanctithomae and pembaensis as subspecies

Distribution and population
Treron sanctithomae is endemic to the island of São Tomé, São Tomé e Príncipe (and formerly also nearby Ilhéu das Rolas). It was formerly abundant and remains common at some fruiting trees in forests and less well-visited plantation areas, but is now nearly absent from the most populated northeast of the island (R. F. de Lima in litt. 2011), with apparently reduced numbers at areas such as Lagoa Amelia and Monte Carmo, and hunters reporting capture rates less than half of those five years previously (F. Olmos in litt. 2007, 2008, 2009, 2011; M. Carvalho in litt. 2009, 2011).

Population justification
The population is suspected to number fewer than 10,000 mature individuals (R. F. de Lima in litt. 2011). It is placed in the band 2,500-9,999 mature individuals, equating to 3,750-14,999 individuals in total, rounded here to 3,500-15,000 individuals.

Trend justification
A population decline of 30-49 % is suspected owing to hunting pressure: the species has disappeared or become scarce in easily accessible areas and hunters have reported capture rates less than half of those five years previously (F. Olmos, M. Carvalho & R. F. de Lima in litt. 2009, 2011).

Ecology
It occurs in primary and secondary tropical and subtropical forest, tolerating forest fragmentation and also occurring in plantations, and is found from sea-level to 1,600 m but is more common above 300 m (del Hoyo et al. 1997; Gibbs et al. 2001). It is generally sedentary but makes local elevational movements. Breeding has been recorded from November to April-May, with the nest built up to 3 m above the ground on a horizontal branch or in a tree fork (del Hoyo et al. 1997; Gibbs et al. 2001). It is a frugivore, feeding mainly in the canopy on a variety of fruits, particularly figs.

Threats
Hunting represents the primary threat to the species. which is caught for consumption in rural communities and by commercial hunters to sell to bars in the capital. Some commercial hunters can kill large numbers at a time, e.g. around 30 killed and a further 30 wounded in a single morning's hunting trip (R. F. de Lima in litt. 2011; R. Rocha in litt. 2011). Hunting pressure is much greater in accessible habitats, and the species is easy to catch with slingshots or air guns (M. Carvalho in litt. 2009, 2011). Habitat loss is believed to have driven the disappearance of the species from Ilhéu das Rolas.

Conservation Actions Underway
Primary forest is protected as a zona ecologica and in Obo Natural Park, although there is no law enforcement within these areas and the lack of data about the species's ecological requirements makes it difficult to assess the benefits of these areas. A new law providing for the gazetting of protected areas has been ratified (F. Olmos in litt. 2007, 2008, 2009, 2011). Conservation Actions Proposed
Research its population size, distribution, ecological requirements and key threats in order to produce conservation recommendations. Ensure designated protected areas are actively protected. List it as a protected species under national law.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Butchart, S., Ekstrom, J., Symes, A.

Contributors
Carvalho, M., Olmos, F., Rocha, R., de Lima, R.

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

Recommended citation
BirdLife International (2014) Species factsheet: Treron sanctithomae. Downloaded from http://www.birdlife.org on 28/07/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 28/07/2014.

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 - Sao Tome green-pigeon (Treron sanctithomae) 0

Key facts
Current IUCN Red List category Vulnerable
Family Columbidae (Pigeons, Doves)
Species name author (Gmelin, 1789)
Population size 2500-9999 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 860 km2
Country endemic? Yes
Links to further information
- Additional Information on this species