Data Zone
Justification of Red List category
Although Apalopteron familiare has a restricted range, it is not believed to approach the thresholds for Vulnerable under the range size criterion which also requires a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation. The population trend is suspected to be stable, and hence does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is larger than 10,000 mature individuals and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
This species' population has been estimated at c.14,700 mature individuals on Hahajima, c.480 mature individuals on Mukohjima and c.420 mature individuals on Imotojima, based on data collected in the late 1990s (Kawakami and Higuchi 2013). These estimates are assumed to equate to a total population of c.15,600 mature individuals, probably equivalent to c.23,400 individuals in total. Although these data are 25 years old, there is no reason to suspect the population has declined since then.
Trend justification
Following historical losses, the range and population are now thought to be stable (K. Kawakami in litt. 2012), and possibly have been for several decades (Kawakami and Higuchi 2003). Kawakami and Higuchi (2013) conducted a population viability analysis and found very little extinction risk for the three populations under present circumstances indicating that the overall population does not currently suffer from habitat loss or nest predation pressure. The probability of extinction for the main (Hahajima) population remained at 0% even when the carrying capacity decreased to 10% of its present value. The other two small populations were found to be more sensitive to any decrease in breeding success rate or carrying capacity (Kawakami and Higuchi 2013). The species continues to be the most frequently and abundantly observed species in its range (eBird 2023) and there is no evidence of a population reduction (Bird Breeding Distribution Survey Committee 2021).
Apalopteron familiare is endemic to the Ogasawara Islands, Japan, where it has been recorded from all three island groups, the Mukojima, Chichijima and Hahajima Islands. The nominate subspecies is now extinct on Mukojima, having not been observed since the 1930s (del Hoyo et al. 2008). The species has also been extirpated from Chichijima (Suzuki and Morioka 2005, Kawakami and Higuchi 2013). On Hahajima, it occurs on the main island and two small satellite islands—Imotojima and Mukohjima (Kawakami et al. 2008; Kawakami and Higuchi 2013)—with the majority of the population found on the main island.
It inhabits primary forest, montane secondary forest, forest edge, bushes, and gardens (Kawakami and Higuchi 2003). On Hahajima it favours well-developed wet forest, foraging mainly 0-10 m above the ground, mainly on invertebrates (Kawakami and Higuchi 2003). The species is rarer in lower, dry shrubs at windy peaks or ridges (van Balen 2020). It frequently forages on fruits in the non-breeding season, and especially on introduced fruit species on Hahajima (Kawakami et al. 2009). Nests are situated in tree forks and occasionally in tree cavities (Kawakami and Higuchi 2002b). Breeding is common during the months of March to June (van Balen 2020).
Virtually almost all the original subtropical forest has already been cleared from the Ogasawara Islands, leading to extinction on some islands, presumably as a result of the wholesale destruction of its habitat. Economic development on Hahajima Island, including developments for tourism, and a consequent reduction in forest cover, may have important implications for the species. However, Kawakami and Higuchi (2013) noted that c.60% of the current forest area on Hahajima was cultivated before World War II and that the species may therefore be tolerant of habitat conversion. Predation by domestic and feral cats may pose a minor threat (Kawakami and Higuchi 2002a). Nest predation by introduced black rats may be a threat on Hahajima (Kawakami in litt. 2012), but rats do not currently seem to be affecting the population (Kawakami and Higuchi 2013). Brown rats are apparently established on the satellite islands of Hahajima. Competition with introduced Japanese White-eye Zosterops japonicus was found to have little or no negative effect on this species (Kawakami and Higuchi 2003).
Conservation Actions Underway
It is legally protected in Japan. The Ogasawara Islands are a National Wildlife Protection Area, established primarily for this species. An active conservation programme is underway there, including the propagation and reintroduction of threatened native plants. Feral cat eradication is on-going on Hahajima. Invasive trees are being removed from Hahajima and its satellites. Although rat eradication was planned for Imotojima and Mukohjima, it has not been conducted so far (K. Kawakami in litt 2020).
13.5 cm. Small, yellow and olive-green honeyeater with a distinctive facial pattern. Mainly olive-green upperparts with yellowish tinge, pale yellow below with grey on flanks. Black patch extends from above to below eye and joins black line across forehead. White eye-ring. Black legs. Voice Various whistling calls.
Text account compilers
Fernando, E., Vine, J.
Contributors
Kawakami, K.
Recommended citation
BirdLife International (2024) Species factsheet: Bonin White-eye Apalopteron familiare. Downloaded from
https://datazone.birdlife.org/species/factsheet/bonin-white-eye-apalopteron-familiare 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.