Locustella fluviatilis
Silhouette: Afsarnayakkan · PhyloPic
In 3 days ~10% in a week ~20%
The river warbler (Locustella fluviatilis) is an Old World warbler in the genus Locustella. It breeds in eastern and central Europe and is migratory, wintering in inland southern Africa, from around the Zambezi River south to the vicinity of Pretoria in South Africa.
The genus name Locustella is from Latin and is a diminutive of locusta, "grasshopper". This refers to the song of the common grasshopper warbler and some others in this genus. The specific fluviatilis is Latin for "of a river".
It is a monotypic species, meaning it has no subspecies. This is a largish warbler. The adult has an unstreaked grey-brown back, whitish grey underparts, and a darker undertail, which has white feather tips giving a contrasting pattern. The sexes are identical, as with most warblers, but young birds are yellower below. Some birds can show reduced dark markings on the undertail coverts (caused by more extensive than usual white tips) and thus are closer in appearance to Savi's warbler than typical river warblers. However, they typically still have a streaked breast and more olive colouration on the upperparts.
This is a skulking species which is very... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Białowieża National Park | 🇵🇱 Poland | |
| 2 | Fertő-Hanság National Park | 🇭🇺 Hungary | |
| 3 | Tsavo West National Park | 🇰🇪 Kenya | |
| 4 | Biebrza National Park | 🇵🇱 Poland | |
| 5 | Kiskunság National Park | 🇭🇺 Hungary |
Rare
Under 5% of wildlife watchers report a Eurasian River Warbler sighting in Biebrza National Park on a given day, based on 49 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 163rd most-seen of the 202 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
May and June
In those months about 10% of wildlife watchers report a Eurasian River Warbler in Biebrza National Park on a given day, against under 5% in July to April, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Eurasian River Warbler sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 5
Of the 5 parks where we can rate Eurasian River Warbler sightings, Biebrza National Park ranks 4th at under 5%. The best odds are in Białowieża National Park (Poland, about 20%), Fertő-Hanság National Park (Hungary, about 10%) and Tsavo West National Park (Kenya, about 10%).
Same genus: Locustella
The closest relatives of the Eurasian River Warbler that you can see in Biebrza National Park (genus Locustella, Locustellid Bush Warblers and Allies) are Savi's Warbler (about 30%) and Grasshopper Warbler (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Eurasian River Warbler is recorded against all the birds logged in Biebrza National Park (49 verified sightings from 2019 to 2026), 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.
