Phylloscopus fuscatus
Silhouette: Jiekun He · PhyloPic
In 3 days ~40% in a week ~70%
The dusky warbler (Phylloscopus fuscatus) is a leaf warbler which breeds in the east Palearctic. The genus name Phylloscopus is from Ancient Greek phullon, "leaf", and skopos, "seeker" (from skopeo, "to watch"). The specific fuscatus is from Latin fuscus "dark".
This warbler is strongly migratory and winters in South Asia and South-east Asia. It sometimes occurs in North America in Alaska, and has also occurred in California. This is an abundant bird of taiga bogs and wet meadows. The nest is built low in a bush, and 5–6 eggs are laid. Like most Old World warblers, this small passerine is insectivorous.
The dusky warbler is prone to vagrancy as far as western Europe in October, despite a 3000 km distance from its breeding grounds. It has wintered in Great Britain. This is a warbler similar in size and shape to a chiffchaff. The adult has an unstreaked brown back and buff underparts. There is a prominent whitish supercilium, and the bill is fine and pointed. The sexes are identical, as with most warblers, but young birds are more olive-tinged above. Like most warblers, it is insectivorous, but will take other small food items, including berries.
The song is a monotonous whistle, and the call is a harsh check. The call is often the first clue that this typically skulking species is present, away from the breeding grounds. An individual of this locally rare species was detected in an urban park and later ringed in December 2025 in Porto, Portugal Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Gobi Gurvansaikhan National Park | 🇲🇳 Mongolia | |
| 2 | Kaziranga National Park | 🇮🇳 India | |
| 3 | Manas National Park | 🇮🇳 India | |
| 4 | Sundarbans National Park | 🇮🇳 India | |
| 5 | Cuc Phuong National Park | 🇻🇳 Vietnam | |
| 6 | Chitwan National Park | 🇳🇵 Nepal | |
| 7 | Royal Manas National Park | 🇧🇹 Bhutan | |
| 8 | Khao Yai National Park | 🇹🇭 Thailand | |
| 9 | Kaeng Krachan National Park | 🇹🇭 Thailand | |
| 10 | Cat Tien National Park | 🇻🇳 Vietnam | |
| 11 | Namdapha National Park | 🇮🇳 India | |
| 12 | Doi Inthanon National Park | 🇹🇭 Thailand | |
| 13 | Taroko National Park | 🇹🇼 Taiwan | |
| 14 | Keoladeo National Park | 🇮🇳 India | |
| 15 | Jim Corbett National Park | 🇮🇳 India |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Xiuying District | 🇨🇳 China | |
| 2 | Quanzhou | 🇨🇳 China | |
| 3 | Tuen Mun | 🇨🇳 China | |
| 4 | Đà Nẵng | 🇻🇳 Vietnam | |
| 5 | Hanoi | 🇻🇳 Vietnam | |
| 6 | Jinan | 🇨🇳 China | |
| 7 | Nanchang | 🇨🇳 China | |
| 8 | Chattogram | 🇧🇩 Bangladesh | |
| 9 | Savar | 🇧🇩 Bangladesh | |
| 10 | Hong Kong | 🇨🇳 China |
Possible
About 20% of wildlife watchers report a Dusky Warbler sighting in Ulaanbaatar on a given day, based on 18 verified sightings from GBIF citizen-science data. It is the 26th most-seen of the 63 birds we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
September
In that month about 50% of wildlife watchers report a Dusky Warbler in Ulaanbaatar on a given day, against about 10% in August and October–June, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Dusky Warbler sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
11th of 46
Of the 46 cities where we can rate Dusky Warbler sightings, Ulaanbaatar ranks 11th at about 20%. The best odds are in Xiuying District (China, about 40%), Quanzhou (China, about 30%) and Tuen Mun (China, about 30%).
GBIF citizen-science records
It is estimated from how often the Dusky Warbler is recorded against all the birds logged in Ulaanbaatar (18 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
