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 Cairngorms National Park on a given day, based on 8 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 189th 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 40%, if each day is a fresh chance.
May
In that month about 20% of wildlife watchers report a Brown Silver-Line in Cairngorms National Park on a given day, against under 5% in July to April, 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.
5th of 6
Of the 6 parks where we can rate Brown Silver-Line sightings, Cairngorms National Park ranks 5th 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%).
Same order: Lepidoptera
The closest relatives of the Brown Silver-Line that you can see in Cairngorms National Park (order Lepidoptera, Butterflies and Moths) are Oak Eggar (about 40%), Scotch Argus (about 40%) and Speckled Wood (about 40%), 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 Cairngorms National Park (8 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.
