Justification of Red List Category
This species has been listed as Critically Endangered (Possibly Extinct) because, of three known individuals in 1998, one died in captivity in 2004 and the remaining two individuals have not been seen since 2003 and 2004. Continued surveys in areas of potential habitat have not detected any other individuals. If any do still survive, the total population must be tiny.
One of the last three known individuals died in captivity in 2004. The other two have not been seen since 2003 and 2004 respectively. No new individuals have been found since 1998 (K. Swinnerton in litt. 2006). If any birds remain, the population is assumed to be tiny (fewer than 50 individuals and mature individuals).
Since its discovery in 1973 when there were an estimated 100-200 individuals, the population declined to just three known individuals in 1998, and all these may now have died. Thus the population is estimated to have experienced an extremely rapid decline over the last three generations or 15 years.
Melamprosops phaeosoma is endemic to Maui in the Hawaiian Islands (USA), where it was discovered in 1973 in the Ko`olau Forest Reserve on the north-eastern flanks of Haleakala (Pratt et al. 1997, Rosa et al. 1998), and estimated to number fewer than 200 birds. During 1975-1985, there was a rapid decline in density in the upper Hanawi watershed (Mountainspring et al. 1990), the last area from which it was known. In 1995, only five to seven birds were known but, by mid-1997, only three individuals could be found (two male, one possibly female), each with distinct home ranges in Hanawi Natural Area Reserve (NAR) and the immediately adjacent Haleakala National Park (Baker 2000). One of three known individuals (male) was captured in September 2004 but died on 28 November 2004 (K. Swinnerton in litt. 2006, VanderWerf et al. 2006). The two other individuals may both have been male, but neither have been seen since 2003 and 2004 (K. Swinnerton in litt. 2006) and are likely to have now died (K. Swinnerton in litt. 2006). No other individuals have been located since 1998 despite almost constant presence of researchers in the field in recent years (K. Swinnerton in litt. 2006), but it is still possible, albeit unlikely, that a few unlocated individuals may exist in the wild (VanderWerf et al. 2006).
It is found in remote `ohi`a forest (T. Pratt in litt. 1999) at 1,400-2,100 m, but this may be suboptimal habitat as subfossil evidence indicates that it occurred in much drier habitat at 300-1,500 m (Mountainspring et al. 1990, Reilly 1998, P. Baker in litt. 1999). It feeds primarily on snails, insects, and spiders, and occasionally fruit (Pratt et al. 1997, M. Collins in litt. 1999). The two known nests were found in `ohi`a trees (Pratt et al. 1997).
Habitat destruction and modification, and the rapid spread of disease-carrying mosquitoes in the lowlands are thought to be responsible for past declines, and the latter continues to be a threat (Mountainspring et al. 1990, T. Pratt in litt. 1999). The precise causes of the recent population decline are unknown (Rosa et al. 1998), although a correlation with a concurrent 473% increase in pig activity within the Hanawi NAR has been hypothesised, as indexed by ground-cover disturbance (Mountainspring et al. 1990). Predation by introduced rats, cats and small Indian mongooses Herpestes auropunctatus is also possible. Rats and the introduced garlic snail (Oxychilus alliarius) have been blamed for the decline of native land snails, an important food source for the Po'o-uli (Groombridge et al. 2004).
Conservation Actions Underway
In 1986, the 30 km2 Hanawi NAR was created to protect this species and, during 1990-1997, all feral pigs were systematically eradicated from three fenced areas (Anderson and Stone 1993, Pratt et al. 1997, Reilly 1998, Rosa et al. 1998). An environmental assessment has been produced and a management plan proposed (USFWS and Hawai`i DLNR 1999, Groombridge et al. 2004). Two wild birds were briefly united when one was caught and moved into the home range of another. However, after just one day the translocated bird had returned to its own territory (Groombridge et al. 2004). One of three known individuals was captured in September 2004 but died in captivity on 28 November 2004 (K. Swinnerton in litt. 2006). The 2006 East Maui Forest Bird Survey covered 216 stations on 8 transects within Po'ouli habitat, and failed to locate any birds. In 2006, the East Maui Watershed Partnership (EMWP) completed a c. 5000 ha fenced unit adjacent to and east of Hanawi NAR incorporating the Ko'olau Forest Preserve, Haiku Uka and Waikamoi Forest Preserve, between about 1,000m and 2,400 m elevation. Feral ungulate control was completed by 2012, although continued maintenance and ungulate surveys continue regularly.
14 cm. Chunky, short-tailed passerine with heavy, somewhat finch-like bill. Adult brown above, greyish-white below, with broad black mask extending behind eye. Grey above mask, shading into brown of crown, with bold, pale patch just behind mask. Juvenile similar but buffier below with smaller mask without grey above. Voice Song a quiet jumble of chittering notes. Call a loud chirk, often in short series.
Text account compilers
Benstead, P., Bird, J., Butchart, S., Capper, D., Derhé, M., Harding, M., Isherwood, I., Stattersfield, A., Symes, A., North, A.
Gorresen, M., Pratt, T., Camp, R., Mounce, H., Swinnerton, K., Woodworth, B., Collins, M., Fretz, S., Baker, P.E., VanderWerf, E.
BirdLife International (2019) Species factsheet: Melamprosops phaeosoma. Downloaded from http://www.birdlife.org on 18/04/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/04/2019.