Poo-uli (Melamprosops phaeosoma)
Posted on 31 December, 2004 in Extinct
Year Last Seen:
2004
Comments:
Endemic to the island of Maui, Hawaii, this species was first discovered in 1973. However, it declined rapidly between 1975 and 1985, predominantly due to invasive species and disease. By mid-1997 only three individuals remained. One was captured in 2004, but it died later that year. The other two individuals have not been reported since 2003 and 2004, with no others reported despite intensive surveys. A set of papers published in 2017 (Akcakaya et al. 2017, Keith et al. 2017, Thompson et al. 2017) laid out methods for quantitatively estimating a species’s probability of extinction based on parameters associated with threats, in addition to records and surveys. Based on the application of these methods (Butchart et al. 2018), this species is regarded as extinct.
Habitat:
It was found in remote ohia 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 fed 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 ohia trees (Pratt et al. 1997).
Causes:
Habitat destruction and modification, and the rapid spread of disease-carrying mosquitoes in the lowlands are thought to be responsible for past declines (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 Poo-uli (Groombridge et al. 2004).
Distribution:
Melamprosops phaeosoma was 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 2001). 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).