Petrophora chlorosata
In 3 days ~10% in a week ~30%
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 |
Rare
Under 5% of wildlife watchers report a Brown Silver-Line sighting in London on a given day, based on 38 verified sightings from GBIF citizen-science data. It is the 559th most-seen of the 1504 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.
May and June
In those months about 10% of wildlife watchers report a Brown Silver-Line in London 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.
3rd of 4
Of the 4 cities where we can rate Brown Silver-Line sightings, London ranks 3rd at under 5%. The best odds are in Porto (Portugal, about 10%) and Birmingham (United Kingdom, about 10%).
GBIF citizen-science records
It is estimated from how often the Brown Silver-Line is recorded against all the insects logged in London (38 verified sightings), 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.
