Petrophora chlorosata
In 3 days ~50% in a week ~80%
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 Biebrza National Park on a given day, based on 9 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 40th most-seen of the 97 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
May
In that month about 40% of wildlife watchers report a Brown Silver-Line in Biebrza National Park on a given day, against under 5% in March–April and July–October, the lowest months. December has too few records to rate.
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.
Among the best
Of the 6 parks where we can rate Brown Silver-Line sightings, Biebrza National Park ranks 2nd at about 20%, level with the leaders once rounded. The best odds are in Snowdonia National Park (United Kingdom, about 20%).
Same order: Lepidoptera
The closest relatives of the Brown Silver-Line that you can see in Biebrza National Park (order Lepidoptera, Butterflies and Moths) are Map (about 40%), European Peacock Butterfly (about 40%) and Spongy Moth (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 Biebrza National Park (9 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.
