Data Zone
Justification of Red List category
Population justification
Using spatially explicit habitat models linked to density functions conducted, Oleiro and Kesler (2015) estimated a population of 100,803 individuals on Pohnpei. This is roughly equivalent to 67,202 mature individuals, placed here in the band 50,000-99,999 mature individuals.
Trend justification
The results of surveys conducted in 1994 suggested that a decline of 74-75% had occurred since 1983 (Buden 2000). Compared with surveys in 1994 (Buden 2000), Oleiro and Kesler (2015) found that detection rates in surveys conducted in 2012 decreased by 20.4%. This is equivalent to a rate of decline of 16.3% over three generations (14.1 years [Bird et al. 2020]). The authors also found that since 1983, detection rates in mangroves increased, but decreased over time in all other habitats (R. Davis in litt. 2020). Modelling of future landscape scenarios by Oleiro and Kesler (2015) predicted that the population would increase by 15% over 100 years. This would be equivalent to an increase of c.2% over three generations, suggesting that in future the population may become stable to increasing. However, detections of this species were negatively associated with disturbed habitats (R. Davis in litt. 2020), and despite a slowing of the rate that native forests are converted to agriculture, it appears to still be ongoing (B. Raynor in litt. 2012; Ellis et al. 2018), and therefore the overall current population trend is suspected to be declining.
Trichoglossus rubiginosus is endemic to the island of Pohnpei and forested islets of Ant Atoll, in the eastern Caroline Islands, Federated States of Micronesia (Engbring et al. 1990; del Hoyo et al. 1997).
The species is found throughout the island up to c.600 m, occurring in a broad range of habitats including plantations, dense forest, secondary forest, mangroves (Juniper and Parr 1998) and around urban areas (Engbring et al. 1990; J. R. Gilardi in litt. 2011; M. O'Brien in litt. 2011). Oleiro and Kesler (2015) noted that the species prefers undisturbed upland forest and mangrove habitats, both of which have declined on Pohnpei. Detections of this species were negatively associated with disturbed habitats (Oleiro and Kesler 2015).
It feeds on nectar, pollen and fruit, particularly favouring nectar from coral trees Erythrina fusca and mango Mangifera indica fruit, but also noted to favour flowers of coconuts, bananas and Elaeocarpus species (Engbring et al. 1990; Juniper and Parr 1998). The species nests in the tops of coconut palms or in cavities in large trees (Juniper and Parr 1998), but also shows a preference for Xylocarpus mangroves (Engbring et al. 1990). Nesting generally takes place from December to May, although there is evidence of breeding outside this period, and only one egg is laid by each female (Juniper and Parr 1998).
Although the species is known to use a range of habitats, it may have suffered some negative effects from deforestation, which has been rapid. Overall, there was a reduction of undisturbed upland forest on Pohnpei of over 60% from 1975 to 1995 (Buden 1996, 2000; B. Raynor in litt. 1995, 2012; Oleiro and Kesler 2015). The majority of the island's forests have been to various degrees converted or at least degraded to mixed forest (native species mixed with lowland secondary species), largely attributable to the cultivation of sakau (= kava) Piper methysticum as a major cash-crop (B. Raynor in litt. 2012). The fragmentation of such forest by sakau clearings also introduces and encourages the spread of invasive species in isolated areas throughout the forest. Although efforts over the past 20 years to reduce the amount of clear-cutting for sakau plantations have resulted in the slowing of native forest conversion rates, the trend remains negative (B. Raynor in litt. 2012). There is a history of this species being hunted for food, persecuted for its perceived pest status and superstitious associations, and captured for trade, with the presence of some birds in captivity suggesting that nest poaching is still taking place (J. R. Gilardi in litt. 2010, 2011; M. O'Brien in litt. 2011). Its pest status may be exaggerated, as it apparently only inflicts minor damage on crops such as mangoes (Engbring et al. 1990). Climate change and sea level rise may impact this species in future by causing the loss and degradation of its mangrove habitat (Oleiro and Kesler 2015).
Conservation Actions Underway
It is now the official state bird of Pohnpei and thus killing, trapping and export of the species are illegal (Engbring et al. 1990; Juniper and Parr 1998). Campaigns have been successful at reducing persecution and hunting pressure, as well as forest clearance for agriculture by encouraging cultivation at lower elevations (Buden 2000). However, there has been resistance to the latter because sakau grows better on wet mountain slopes and crops are likely to be safer in more remote areas (Buden 2000).
24 cm. Head and upperparts deep maroon, darkest on the head. Scapulars and coverts deep maroon; flight feathers blackish on the inner webs, olive-yellow on the outer webs, yellowest on the outermost primaries. Underwing black. Underparts deep maroon, edged black, giving a slightly barred appearance. Uppertail olive-yellow, getting brighter towards the tip; undertail pale olive-yellow. Bill orange; iris yellow-orange; legs dark grey. Females are told by yellowish bill and greyish-white iris. Immatures have more pointed tail feathers.
Text account compilers
Clark, J.
Contributors
Butchart, S., Davis, R.A., Derhé, M., Ekstrom, J., Gilardi, J., Gilardi, J.R., O'Brien, M., Raynor, B. & Taylor, J.
Recommended citation
BirdLife International (2024) Species factsheet: Pohnpei Lorikeet Trichoglossus rubiginosus. Downloaded from
https://datazone.birdlife.org/species/factsheet/pohnpei-lorikeet-trichoglossus-rubiginosus on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.