Petrophora chlorosata
In 3 days ~20% in a week ~40%
Petrophora chlorosata, the brown silver-line, is a moth of the family Geometridae found in Asia and Europe. The larvae feed on bracken. It was first described by the Italian physician and naturalist, Giovanni Antonio Scopoli in his 1763 Entomologia Carniolica. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Biebrza National Park | 🇵🇱 Poland | |
| 3 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 4 | Cévennes National Park | 🇫🇷 France | |
| 5 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 6 | Pyrénées National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Porto | 🇵🇹 Portugal | |
| 2 | Birmingham | 🇬🇧 United Kingdom | |
| 3 | London | 🇬🇧 United Kingdom | |
| 4 | Helsinki | 🇫🇮 Finland |
With luck
About 10% of wildlife watchers report a Brown Silver-Line sighting in Cévennes National Park on a given day, based on 21 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 401st most-seen of the 996 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
May
In that month about 20% of wildlife watchers report a Brown Silver-Line in Cévennes National Park on a given day, against under 5% in July to March, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Brown Silver-Line sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 6
Of the 6 parks where we can rate Brown Silver-Line sightings, Cévennes National Park ranks 4th at about 10%. The best odds are in Snowdonia National Park (United Kingdom, about 20%), Biebrza National Park (Poland, about 20%) and Bavarian Forest National Park (Germany, about 10%).
GBIF citizen-science records
It is estimated from how often the Brown Silver-Line is recorded against all the insects logged in Cévennes National Park (21 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.
