- Phylloscopus borealis
Identification
Length 12–13 cm (4¾-5 in), weight 7.5–15 g
- Olive-green above, greyish-white below. A single noticeable wing bar, and another less distinct, in fresh plumage (though sometimes one or both can be lost when feathers become worn). Long white supercillium and a broad dark eyestripe.
- Thick wedge-shaped bill, with a dark tip to the lower mandible.
- Flat forehead and slight peak to the hindcrown.
- Legs pinkish-brown.
Similar Species
See Japanese Leaf Warbler and Kamchatka Leaf Warbler for the complex identification of these recently split taxa. Can also be confused with Greenish Warbler, which is slightly smaller and has a different, disyllabic call.
Distribution
Breeds in Alaska, northern Asia, Scandinavia, and Siberia.
Migration mostly through eastern Asia, but rare but increasing sightings in western Europe, including the east coast of the UK, in the autumn.
Winters South-east Asia, Thailand, Burma and Indonesia.
Vagrant in northern Western Australia.
Taxonomy
Japanese Leaf Warbler P. xanthodryas and Kamchatka Leaf Warbler P. examinandus were formerly included in this species as additional subspecies.
Subspecies
Two[1] to four[2] subspecies are recognised:
- P. b. borealis:
- Scandinavia to Chukotsk Peninsula; winters to south-eastern China and Philippines.
- P. b. transbaicalicus:
- P. b. hylebata:
- Eastern Amurland to northern Manchuria, Ussuriland and North Korea. Included in P. b. borealis by IOC[1].
- P. b. kennicotti:
- Western Alaska; winters in Philippines.
One other named subspecies, P. b. talovka, is generally treated as a synonym of P. b. borealis.
Habitat
Mixed coniferous, birch and other broadleaved woods, also in lush undergrowth near water. Most are in lowlands but the Kamtchatka breeds in higher elevation subalpine forests.
Behaviour
Very active bird, constantly flitting around in the tree canopy.
Flight
Dashing flight. Flicks wings and tail when at rest.
Breeding
The nest is on the ground in a low shrub.
Diet
The diet includes small arthropods, picked off vegetation or in flight.
Vocalisation
<flashmp3>Phylloscopus borealis (song).mp3</flashmp3>
Listen in an external program
References
- Gill, F. and Donsker, D. (Eds). 2017. IOC World Bird Names (version 7.3). Available at http://www.worldbirdnames.org/.
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2018. The eBird/Clements checklist of birds of the world: v2018. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- Taxonomy thread discussing Arctic Warbler read in June 2009
- Wikipedia
- BTO Bird Facts
- Collins Field Guide 5th Edition
- Collins Bird Guide ISBN 0 00 219728 6
Recommended Citation
- BirdForum Opus contributors. (2024) Arctic Warbler. In: BirdForum, the forum for wild birds and birding. Retrieved 23 November 2024 from https://www.birdforum.net/opus/Arctic_Warbler
