Maroon Pigeon Columba thomensis , São Tomé Bronze-naped Pigeon Columba malherbii and São Tomé Green-pigeon Treron sanctithomae are all endemic to the islands of São Tomé, Príncipe and Annobón. Maroon Pigeon, currently listed as Vulnerable under criterion D1, occurs only on São Tomé as does the Least Concern São Tomé Green-pigeon, while the Least Concern São Tomé Bronze-naped Pigeon occurs on São Tomé, Príncipe and Annobón.
A major threat to all three species is uncontrolled hunting with the bushmeat trade potentially having a negative impact on populations. Maroon Pigeon has an estimated population size of 250-999 mature individuals but it is assumed to be stable. If declines owing to hunting pressure are now evident the species may warrant uplisting to Endangered under criterion C2aii of the IUCN Red List criteria owing to its declining population of <2,500 mature individuals confined to a single population. If the population of São Tomé Green-pigeon and/or São Tomé Bronze-naped Pigeon now approaches 10,000 mature individuals and declines are evident owing to hunting pressure these species could also qualify as Near Threatened (if >10,000) or Vulnerable (if <10,000) under criterion C2aii. Alternatively the species may qualify if declines approach the thresholds under criterion A, i.e. 30% over three generations (12.7 years based on a generation time of 4.2 years, BirdLife International unpublished data).
Comments on these potential category revisions are welcomed, particularly estimates of population size and rate of decline for these species.
(This discussion was first started as part of the 2010 Red List update)
The following figures were submitted by Ricardo Faustino de Lima on 27 January 2011 (not BirdLife data):