Petrophora chlorosata
In 3 days ~60% in a week ~90%
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 |
Possible
About 20% of wildlife watchers report a Brown Silver-Line sighting in Snowdonia National Park on a given day, based on 52 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 20th most-seen of the 387 insects we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
April to June
In those months about 40% of wildlife watchers report a Brown Silver-Line in Snowdonia National Park on a given day, against under 5% in August 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.
Yes
Of the 6 parks where we can rate Brown Silver-Line sightings, Snowdonia National Park has the highest daily chance: about 20%. Next come Biebrza National Park (Poland, about 20%) and Bavarian Forest National Park (Germany, about 10%).
Same order: Lepidoptera
The closest relatives of the Brown Silver-Line that you can see in Snowdonia National Park (order Lepidoptera, Butterflies and Moths) are Drinker Moth (about 50%), Speckled Wood (about 40%) and Oak Eggar (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Brown Silver-Line is recorded against all the insects logged in Snowdonia National Park (52 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.
