 Apparently, all or at least most specimens of the latter were procured over a short period around 1860 by James D. Mills, the last one in 1864.The last reliable sight record was in 1884, with a doubtful one in 1893; a dedicated search in 1887 failed to find the bird, but as it was rather cryptic, this cannot be taken as unequivocal proof that it was completely extinct by then.As neither the small Asian mongoose nor mosquitoes (which transmit fowlpox and avian malaria, both exceptionally lethal to Hawaiian endemic birds) were present on Big Island until 1883 and the 1890s, respectively, this species' extinction was probably caused by introduced European rats, cats and possibly dogs.