Abstract The Timor green pigeon Treron psittaceus , endemic to Timor, Rote, and adjacent satellite islands (eastern Indonesia and Timor-Leste), is declining because of severe hunting pressure and forest conversion. During 2002–2025, we conducted > 1,400 field days of surveys throughout the species’ range. Prior to 2000, most records were from Indonesian West Timor. Since 2000, most records (93%) and nearly all individuals (98%) have been observed in Timor-Leste, primarily within Lautem District. The scarcity of recent records throughout much of the species’ range, including Camplong (last record 1991), Bipolo forest (last record 1999), elsewhere in West Timor (last record 2005) and Rote (four records of 1–2 birds during 2004–2013), suggests that only a small, declining population persists. The population in Indonesia is possibly nearly extinct (and probably functionally so), and that in Timor-Leste is predicted to be lower than current estimates suggest. We conservatively estimate the global population to be 100–500 individuals distributed across eight sites, and consider it plausible that the population size lies towards the lower end of this estimate. A population of > 50 birds is likely restricted to a single site, Nino Konis Santana National Park, underscoring the species’ precarious status. We advocate for a reassessment as Critically Endangered on the IUCN Red List. Effective action plans are required in both Indonesia and Timor-Leste. In Lautem, community-based conservation efforts will be crucial to reduce hunting pressure. Further surveys should focus on Mount Timau (West Timor), and Lautem, Manatuto and Manufahi Districts (Timor-Leste).
Trainor et al. (Tue,) studied this question.