Data Zone
Justification of Red List category
This species has a very small population, which appears to be declining in at least part of its range, probably owing to hunting, predation and expanding cultivation. It has two subpopulations, both of which are now likely to be extremely small. For these reasons, the species is listed as Endangered.
Population justification
On Pohnpei, the population was estimated at 841 birds in 1983-1984 (Engbring et al. 1990). In 1994, a repeat survey recorded a 67% decrease in encounter rate in the lowlands, but no change in the uplands, which equated to a 50% reduction overall (Buden 2000). Therefore, the population size in 1994 is inferred to have been 421 individuals, and assuming the decline continued at the same rate, the population size on Pohnpei in 2020 may be no more than 76 individuals. In 2012, a survey was carried out at 247 stations on 19 transects across Pohnpei and only five individuals were recorded (Oleiro 2014), suggesting that the species is extremely rare on Pohnpei (R. Davis in litt. 2020).
In Chuuk (Truk), the population was estimated to number 294 in 1983-1984 (Engbring et al. 1990). A Chuuk population estimate in 2001 indicated a significantly smaller population (G. Dutson in litt. 2001), although six individuals were seen during a drive along approximately five miles of the coast road on Weno in 2019 (C. Collins in litt. 2020). The species appears to be seen more regularly in Chuuk (C. Collins in litt. 2020, R. Davis in litt. 2020), so it may be declining more slowly there. Assuming that the population declined by 10% between 1983-1984 and 2001, and that the trends continued, the population size today may be in the region of 236 individuals.
Based on the population estimates for Pohnpei and Chuuk from 1983-1984 (Engbring et al. 1990), and subsequent surveys that indicated population declines (F. Amidon in litt. 2007, Buden 2000, Oleiro 2014, G. Dutson in litt. 2001), the total population size is estimated to number 312-715 individuals, roughly equating to 208-477 mature individuals, here rounded to 200-500 mature individuals.
The species is likely to have at least two subpopulations. The largest was previously found in Pohnpei (Engbring et al. 1990), but following declines there, the population in Chuuk may now be larger. Based on the population estimate for Chuuk from 1983-1984 (Engbring et al. 1990), and subsequent surveys that indicated population declines (G. Dutson in litt. 2001), and extrapolating to 2020, the current population size in Chuuk is estimated to be within the range 236-294 individuals, roughly equating to 157-196 mature individuals, here rounded to 150-200 mature individuals.
Trend justification
The population size has probably always been low, at least in historical times (Baker 1951, Engbring et al. 1990).
On Pohnpei, the population was estimated at 841 birds in 1983-1984 (Engbring et al. 1990). In 1994, a repeat survey recorded a 67% decrease in encounter rate in the lowlands, but no change in the uplands, which equated to a 50% reduction overall (Buden 2000). This would equate to a reduction of 69% if it continued at the same rate over three generations (17.7 years), assuming exponential decline. In 2012, a survey carried out at 247 stations on 19 transects across Pohnpei did not detect the species, but five individuals were recorded outside surveys (Oleiro 2014), suggesting that the population on Pohnpei was extremely small.
In Chuuk (Truk) it was estimated to number 294 in 1983-1984 (Engbring et al. 1990). A population estimate in 2001 indicated a significantly smaller population (G. Dutson in litt. 2001). The species appears to be seen more regularly in Chuuk (C. Collins in litt. 2020, R. Davis in litt. 2020), so it may be declining more slowly there.
Based on the results of surveys in both Pohnpei and Chuuk, a continuing decline is inferred. Overall, the population is suspected to have undergone a reduction of 30-49% over the past three generations (17.7 years). Assuming current trends continue, the species is suspected to decline at a similar rate over the next three generations.
Alopecoenas kubaryi is endemic to the Federated States of Micronesia, occurring in Pohnpei and Chuuk (Truk), where it has been recorded on Tol, Weno, Patta, Dublon, Fenepi and Ipis Islands (D. Buden in litt. 2016, Baptista et al. 2020, eBird 2020). Several individuals have also been detected on Ant Atoll (D. Kesler in litt. 2012).
On Pohnpei, it inhabits brushy ravines, appearing to prefer those where hibiscus Hibiscus tiliaceus forms dense thickets. This constitutes a highly disturbed habitat, often occurring near settlements (Baptista et al. 1997). It is also found in lowland forests, mangroves and, less commonly, in montane forest. In Chuuk, it is found in agricultural and native forest at all elevations (Engbring et al. 1990). Surprisingly dense populations have been found on some islets, indicating that coastal strand/forest vegetation is also suitable (J. Lepson in litt. 1999), and it was observed regularly in similar habitats on Fenepi and Ipis Islands (D. Buden in litt. 2016). It has been sighted feeding in fairly degraded habitat on the island of Weno (C. Collins in litt. 2008). It feeds primarily on the ground on seeds, worms and small snails. It nests in deep forest, up to 180 m. In Chuuk, nests with eggs have been found in February, April, June and September. Clutch-size is one (Baptista et al. 1997).
On Pohnpei, predation by introduced species (mainly rats Rattus spp. and cats) and excessive hunting may have caused some depletion (Buden 2000). Habitat loss is also an issue. Overall, there was a reduction of undisturbed upland forest on Pohnpei of over 60% from 1975-1995 (Buden 1996, 2000, B. Raynor in litt. 1995, 2012), with habitat change slowing between 1994 and 2002 (Oleiro et al. 2014). In the 0-100 m elevation zone of Pohnpei, the area of undisturbed habitat decreased by 16% between 1975 and 1994, but changed little between 1994 and 2002 (Oleiro 2014). In the mangrove and 600-800 m elevation zones, the area of undisturbed habitat changed by less than 2% over the two time periods (Oleiro 2014). The majority of the island's forests have been, to varying 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). In Chuuk, the only remaining semi-original forest remains in tiny remnants on the higher reaches of a few islands. Hunting of birds, using catapults, is also known to occur (C. Collins in litt. 2020), and could present a further threat. The potential introduction of Brown Tree Snake (Boiga irregularis) also presents a threat (R. Davis in litt. 2020).
Conservation Actions Underway
The species occurs in Mount Winipot Conservation Area, Chuuk. Traditional leaders have been encouraged to adopt a programme to plant sakau in the lowlands, but resistance is high because the plant grows best on wet mountain slopes and is less likely to be pilfered in more remote areas (Buden 2000). Watershed Forest Reserve boundary lines have been laid down and enforced in Madolenihmw and Uh on Pohnpei (B. Raynor in litt. 2007).
28 cm. Medium-sized, short-tailed dove. Adults mostly black posteriorly, with purplish-crimson back and shoulders. White head and breast with black crown connected at rear with black postocular stripe. Juveniles dark rusty-brown. Voice Low moan, rarely uttered. Hints Shy and retiring, usually in forest but often found in gardens at mid-elevation in Chuuk. Partial to mangroves on Pohnpei.
Text account compilers
Wheatley, H.
Contributors
Amidon, F.A., Benstead, P., Buden, D.W., Collins, C., Davis, R., Derhé, M., Dutson, G., Kesler, D., Khwaja, N., Lepson, J., Mahood, S., North, A., O'Brien, A., O'Brien, M., Raynor, B., Shutes, S., Stattersfield, A. & Wiles, G.
Recommended citation
BirdLife International (2024) Species factsheet: Caroline Islands Ground Dove Pampusana kubaryi. Downloaded from
https://datazone.birdlife.org/species/factsheet/caroline-islands-ground-dove-pampusana-kubaryi on 23/12/2024.
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 23/12/2024.