Catocala fraxini
In 3 days ~10% in a week ~30%
Catocala fraxini, the blue underwing or Clifden nonpareil, is a moth of the family Erebidae. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. The distribution area covers almost the entire central and northern Europe, as well as parts of southern Europe. The species is largely missing in Portugal, the Mediterranean islands (except Corsica), in Greece, in northern Scotland, in northern Scandinavia and north and in southern Russia. The distribution area stretches across the Palearctic to northern Turkey, Siberia, Russian Far East, Korea and Japan.
The name "Clifden nonpareil" is derived from the location of the first British records, at the Cliveden estate in Berkshire in the 18th-century, "nonpareil" meaning "without equal" in French. The moth became extinct as a breeding species in Great Britain by the 1960s with post-war changes to forestry, such as when for example, the larval foodplants aspen and poplar were cleared in Orlestone Forest, Kent to make way for conifers. For decades it was a rare migrant from Europe with just single sightings recorded in some years. Larvae have since been found in Sussex and sightings in... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Bavarian Forest National Park | 🇩🇪 Germany |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Helsinki | 🇫🇮 Finland | |
| 2 | Liverpool | 🇬🇧 United Kingdom | |
| 3 | Novosibirsk | 🇷🇺 Russia | |
| 4 | Yekaterinburg | 🇷🇺 Russia | |
| 5 | Birmingham | 🇬🇧 United Kingdom | |
| 6 | Saint Petersburg | 🇷🇺 Russia | |
| 7 | Moscow | 🇷🇺 Russia | |
| 8 | London | 🇬🇧 United Kingdom | |
| 9 | Vienna | 🇦🇹 Austria |
Rare
Under 5% of wildlife watchers report a Blue Underwing sighting in Bavarian Forest National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 822nd most-seen of the 1115 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
August to October
In those months about 10% of wildlife watchers report a Blue Underwing in Bavarian Forest National Park on a given day, against under 5% in November to July, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Blue Underwing sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
Only Bavarian Forest National Park, in our data
Bavarian Forest National Park is the only park on Wallace's Line with enough records to rate Blue Underwing sightings: under 5% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Blue Underwing is recorded against all the insects logged in Bavarian Forest National Park (6 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.
