Phylloscopus borealis
The Arctic Warbler (Phylloscopus borealis) is a remarkably small, yet incredibly migratory passerine, showcasing the endurance of the avian world. Measuring a mere 11-13 cm (4.3-5.1 in) in length and weighing 7-15 g (0.25-0.53 oz), its plumage is typically drab, presenting as an olive-brown above and yellowish-white below. A prominent, long yellowish-white supercilium (eyebrow stripe) extending behind the eye is its most distinctive field mark, often accompanied by a single, faint yellowish w...
Breeds in boreal forests, often near water, favoring willow and alder scrub, birch woodland, and dwarf birch thickets at various elevations. Winters in tropical broadleaf forests and secondary growth, from lowlands up to moderate altitudes.
Primarily insectivorous, feeding on small insects such as caterpillars, beetles, flies, and their larvae, as well as spiders, typically gleaned from foliage or caught in mid-air.
Arctic Warblers are highly active, diurnal foragers, constantly on the move through vegetation. They employ a combination of gleaning insects from leaves and twigs, hovering, and performing agile flycatching maneuvers to capture prey, often high in the canopy but also in lower shrubs. During the ...
The Arctic Warbler possesses an expansive Holarctic breeding range, spanning northern Scandinavia, Russia, Siberia, the Kamchatka Peninsula, Sakhalin, northern Mongolia, northeastern China, and Hokkaido, Japan, extending eastward to western Alaska (Seward Peninsula). Its wintering grounds are exc...
Least Concern
- The Arctic Warbler holds the record for one of the longest migratory journeys relative to its body size among Old World warblers, with some individuals traveling up to 13,000 km (8,000 miles) one way. - Alaskan breeding populations of Arctic Warblers migrate across the Bering Strait, flying ove...