Idaea biselata
In 3 days ~20% in a week ~50%
The small fan-footed wave (Idaea biselata) is a moth of the family Geometridae. The species was first described by Johann Siegfried Hufnagel in 1767. The species is widespread from the British Isles across western Europe and east to the Urals. In northern Europe, the range extends about to central Fennoscandia. In the south the range extends up to central Portugal, Corsica, the northern Apennines and northern Greece. Isolated occurrences are known from Calabria and the Peloponnese. Outside of Europe it is found in the Caucasus, Transcaucasia, in the north of Turkey, in Siberia, in northern Kazakhstan, as well as in the Russian Far East. The subspecies Idaea biselata extincta (Staudinger, 1897) is represented in Korea and the Ussuri region. It rises to about 1,700 metres above sea level in the Alps. South of the Alps, is found from 600 to 1,500 metres and is rarely found below this range.
It is a small (wingspan 22–25 mm), easily missed species. The wings are creamy white with darker bands with a small black discal spot on each wing. The basic colouring and pattern vary relatively little. The ground colour is yellowish white to slightly brownish... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 3 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany | |
| 5 | Pyrénées National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | Porto | 🇵🇹 Portugal | |
| 3 | Helsinki | 🇫🇮 Finland | |
| 4 | Leeds | 🇬🇧 United Kingdom | |
| 5 | Manchester | 🇬🇧 United Kingdom | |
| 6 | Birmingham | 🇬🇧 United Kingdom | |
| 7 | Nizhny Novgorod | 🇷🇺 Russia | |
| 8 | Moscow | 🇷🇺 Russia | |
| 9 | London | 🇬🇧 United Kingdom | |
| 10 | Saint Petersburg | 🇷🇺 Russia |
With luck
About 10% of wildlife watchers report a Small Fan-Footed Wave sighting in Cairngorms National Park on a given day, based on 11 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 142nd most-seen of the 300 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 50%, if each day is a fresh chance.
August
In that month about 20% of wildlife watchers report a Small Fan-Footed Wave in Cairngorms National Park on a given day, against under 5% in September to June, the lowest months.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Small Fan-Footed Wave sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Among the best
Of the 5 parks where we can rate Small Fan-Footed Wave sightings, Cairngorms National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Snowdonia National Park (United Kingdom, about 10%) and Bavarian Forest National Park (Germany, about 10%).
GBIF citizen-science records
It is estimated from how often the Small Fan-Footed Wave is recorded against all the insects logged in Cairngorms National Park (11 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.
