{{Short description|Species of bird}} {{Speciesbox | status = LC | status_system = IUCN3.1 | status_ref = <ref>BirdLife International 2017. Phylloscopus xanthodryas (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22735629A113113489. https://dx.doi.org/10.2305/IUCN.UK.2017-1.RLTS.T22735629A113113489.en. Downloaded on 13 January 2020.</ref> | image = Japanese Leaf Warbler imported from iNaturalist photo 303806409 on 20 June 2024.jpg | taxon = Phylloscopus xanthodryas | authority = (R. Swinhoe, 1863) | synonyms = *''Phylloscopus borealis xanthodryas'' }}

The '''Japanese leaf warbler''' ('''''Phylloscopus xanthodryas''''') is a leaf warbler (family Phylloscopidae). The species was first described by Robert Swinhoe in 1863. It was formerly included in the "Old World warbler" assemblage. It is closely related to the Arctic warbler and the Kamchatka leaf warbler, to which it was formerly considered conspecific.<ref>{{Cite journal|url=https://www.hbw.com/species/japanese-leaf-warbler-phylloscopus-xanthodryas |title=Japanese Leaf-warbler (''Phylloscopus xanthodryas'')|website=www.hbw.com |year=2020 |doi=10.2173/bow.arcwar3.01 |access-date=2018-11-29|last1=Del Hoyo |first1=Josep |last2=Collar |first2=Nigel |last3=Christie |first3=David |s2cid=243313702 |editor-first1=Josep |editor-first2=Andrew |editor-first3=Jordi |editor-first4=David |editor-first5=Eduardo |editor-last1=Del Hoyo |editor-last2=Elliott |editor-last3=Sargatal |editor-last4=Christie |editor-last5=De Juana |url-access=subscription }}</ref>

It is found throughout Japan, except on Hokkaido; it winters to Southeast Asia.<ref>{{Cite web|url=https://www.researchgate.net/publication/280383942|title=A record of Japanese Leaf Warbler ''Phylloscopus xanthodryas'' in Thailand|website=ResearchGate|language=en|access-date=2018-11-29}}</ref>

== Description == The Japanese Leaf-Warbler is sized between 12–13&nbsp;cm in length.<ref name=":0">{{Cite journal |last=del Hoyo |first=Josep |last2=Collar |first2=Nigel |last3=Christie |first3=David |date=2020 |title=Japanese Leaf Warbler (Phylloscopus xanthodryas), version 1.0 |url=https://birdsoftheworld.org/bow/species/arcwar3/cur/introduction |journal=Birds of the World |language=en |doi=10.2173/bow.arcwar3.01 |issn=2771-3105|url-access=subscription }}</ref> They typically have darker green upper body feathers, with an under body (or belly) with lighter green feathers.<ref name=":0" /> They have a very short and black (with a hint of yellow) beak, as well as extremely small legs that vary from pale yellow to orange-brown.<ref name=":0" /> The bird has a clear yellowish-white eyebrow stripe above the bird's dark eyes.<ref name=":0" /> Adults are bright olive-green (with a white wingbar and greenish tail).<ref name=":0" /> Both sexes look alike. Juveniles are roughly similar, yet duller in color (more grey-brown).<ref name=":0" />

== Subspecies == Monotypic, only existing form of this species of bird and there are no further subdivisions.<ref name=":0" />

== General Habitat == This species lives in mixed and deciduous forests, as well as in coniferous woods and thickets.<ref name=":0" /> It is usually found between 1500 and 2500 meters in elevation, but most often below 2200 meters. It nests in thick undergrowth, rhododendron bushes, and scrub above the tree line.<ref name=":0" /> In winter, it is seen below 1800 meters in woodlands, rainforests, secondary growth, plantations, and gardens.<ref name=":0" /> It also occurs in shrublands, wetlands, and cultivated areas, as well as artificial terrestrial habitats.<ref name=":1">{{Cite journal |last=BirdLife International (BirdLife International) |date=2024-06-12 |title=IUCN Red List of Threatened Species: Phylloscopus xanthodryas |url=https://www.iucnredlist.org/species/22735629/263891276 |journal=IUCN Red List of Threatened Species |archive-url=https://web.archive.org/web/20250429220728/https://www.iucnredlist.org/species/22735629/263891276 |archive-date=2025-04-29 |access-date=2025-10-14 |url-status=live }}</ref> The species depends on thick vegetation for nesting and foraging.<ref name=":1" />

== Distribution == The Japanese leaf warbler breeds mainly in Japan, from Honshu to Kyushu.<ref name=":0" /> In the non-breeding season, it is found in areas such as Taiwan, the Philippines, Borneo, Java, and in small numbers as far east as the Moluccas.<ref name=":0" /> It also winters in Brunei, Indonesia, Malaysia, and parts of China.<ref name=":1" />

=== Movements and Migration === The Japanese leaf warbler is a migratory bird.<ref name=":0" /> After breeding, it moves south or southwest through eastern China and nearby islands.<ref name=":0" /> It spends the winter in Taiwan, the Philippines, Borneo, and Java.<ref name=":0" /> Migration takes place from August to November, and the birds return to Japan in mid-May.<ref name=":0" /> Arrival often happens within one or two weeks, although timing can be confused with other related species.<ref name=":0" />

== Diet and Foraging == Its diet is made up mostly of insects and their larvae.<ref name=":0" /> Common food items include midges, ants, grasshoppers, caterpillars, beetles, spiders, and small snails.<ref name=":0" /> In autumn, it may also eat berries.<ref name=":0" /> The warbler usually forages alone or in pairs but can join mixed groups of birds outside of the breeding season.<ref name=":0" /> It searches for food in trees, shrubs, and on the ground, and it sometimes catches insects while flying.<ref name=":0" />

== Sounds and Vocal Behavior == The song of the Japanese leaf warbler is a series of short phrases repeated several times, often lasting 1.5–2 seconds.<ref name=":0" /> It is lower in pitch than that of related species such as P. examinandus and has a slower rhythm than P. borealis.<ref name=":0" /> Its call is a dry “brrt” sound, which is lower and softer compared to the calls of similar warblers.<ref name=":0" />

== Breeding == Breeding takes place from June to August, and pairs often raise two broods in a season.<ref name=":0" /> The species is mostly monogamous.<ref name=":0" /> Males sing to mark their territory, and nests are built on the ground among plants or bamboo.<ref name=":0" /> Nests are round and made of moss, stalks, and animal fur, with an opening at the side.<ref name=":0" /> The clutch usually contains four to five white eggs with small dark spots.<ref name=":0" /> The female incubates the eggs for about 12–13 days, and chicks leave the nest 13–14 days after hatching.<ref name=":0" /> Both parents feed the young, though sometimes the female cares for them alone.<ref name=":0" /> Nests are often targeted by cuckoos, which lay their eggs inside, and snakes may also prey on them.<ref name=":1" />

== Conservation status == The Japanese leaf warbler is currently classified as Least Concern on the IUCN Red List (assessed June 12, 2024).<ref name=":1" /> The population trend is considered stable, and there is no evidence of major declines or severe fragmentation.<ref name=":0" /> Exact numbers of mature individuals are unknown,<ref name=":1" /> but it is locally common, with male territory density estimated at 10–30 birds per square kilometer.<ref name=":0" /> Its average generation length is estimated at about 2 years.<ref name=":1" />

==References== {{Reflist}}

== External links == * [https://ebird.org/species/arcwar3 eBird website]

{{Taxonbar |from=Q12265907}}

Japanese leaf warbler Category:Birds of Japan Japanese leaf warbler Category:Taxa named by Robert Swinhoe