The millerbird is a species of Old World warbler in the family Acrocephalidae endemic to the Hawaiian Islands.
Region
Hawaiian Archipelago
Typical Environment
The millerbird is confined to small, low, remote islands with dense native shrub and grass communities. On Nihoa it occupies naupaka (Scaevola) thickets and bunchgrass (Eragrostis) slopes, using dense cover for foraging and nesting. The reintroduced population on Laysan uses similar coastal shrublands and interior grass-shrub mosaics. It avoids open, unvegetated areas and relies on intact native vegetation with layered structure.
Altitude Range
Sea level to 270 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 1/5
The millerbird is a small reed-warbler endemic to the Northwestern Hawaiian Islands, with populations on Nihoa and a reintroduced population on Laysan. The original Laysan subspecies was extirpated in the early 20th century, but translocations from Nihoa beginning in 2011 reestablished the species there. It is highly terrestrial for a warbler, skulking through dense shrubs to glean insects. Its extreme range restriction makes it vulnerable to storms, invasive species, and habitat change.
Temperament
skulking and territorial
Flight Pattern
short rapid wingbeats
Social Behavior
Usually found in pairs or family groups, maintaining small territories year-round. Monogamous pairs build cup nests low in dense shrubs or grasses. Breeding occurs in the warmer months with both parents feeding the young; they are attentive and defensive near the nest.
Migratory Pattern
Resident
Song Description
Song is a brisk, scratchy warble with varied chattering notes delivered from within cover. Calls include sharp tacks and scolds when alarmed, becoming more frequent near the nest.
Plumage
Subtly colored reed-warbler with brown-olive upperparts and buff to grayish underparts, often slightly warmer on the flanks. Feathers are plain with minimal streaking, giving a smooth, matte appearance suited to camouflage in shrubs.
Diet
Feeds primarily on insects and other small arthropods, including beetles, caterpillars, flies, spiders, and true bugs. It gleans prey from leaves, twigs, and bark, and occasionally hawks short distances to snatch flying insects. Foraging is methodical and close to the ground within dense foliage.
Preferred Environment
Dense native shrublands, especially naupaka thickets and bunchgrass edges, where cover and prey are abundant. It prefers structurally complex patches that provide both foraging substrates and concealment.
