Gonepteryx rhamni
In 3 days ~50% in a week ~80%
Gonepteryx rhamni, commonly named the Common Brimstone, is a butterfly of the family Pieridae. It lives throughout the Palearctic zone and is commonly found across Europe, Asia, and North Africa. Across much of its range, it is the only species of its genus, and is therefore simply known locally as the Brimstone. Its wing span size is 60–74 mm (2.4–2.9 in). It should not be confused with the Brimstone moth Opisthograptis luteolata.
The brimstone relies on two species of buckthorn plants as host plants for its larvae; this influences its geographic range and distribution, as these plants are commonly found in wetlands. The adult brimstone travels to woodland areas to spend seven months overwintering. In spring when their host plants have developed, they return to the wetlands to breed and lay eggs. Both the larval and adult forms of the common brimstone have protective coloration and behaviour that decreases their chances of being recognised and subsequently preyed upon.
The adult common brimstone has sexual dimorphism in its wing coloration: males have yellow wings and iridescence while females have greenish-white wings and are not iridescent. This iridescence is affected by environmental factors.
The name "butterfly" is believed to have originated from this species, which was called the "butter-coloured fly" by early British naturalists. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Biebrza National Park | 🇵🇱 Poland | |
| 2 | Triglav National Park | 🇸🇮 Slovenia | |
| 3 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 4 | Tatra National Park | 🇸🇰 Slovakia | |
| 5 | Białowieża National Park | 🇵🇱 Poland | |
| 6 | Aigüestortes National Park | 🇪🇸 Spain | |
| 7 | Plitvice Lakes National Park | 🇭🇷 Croatia | |
| 8 | Gauja National Park | 🇱🇻 Latvia | |
| 9 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 10 | Picos de Europa National Park | 🇪🇸 Spain | |
| 11 | Mercantour National Park | 🇫🇷 France | |
| 12 | Ordesa y Monte Perdido National Park | 🇪🇸 Spain | |
| 13 | Pyrénées National Park | 🇫🇷 France | |
| 14 | Cévennes National Park | 🇫🇷 France | |
| 15 | Ecrins National Park | 🇫🇷 France | |
| 16 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 17 | Vanoise National Park | 🇫🇷 France | |
| 18 | Fertő-Hanság National Park | 🇭🇺 Hungary | |
| 19 | Wadden Sea National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Helsinki | 🇫🇮 Finland | |
| 2 | Warsaw | 🇵🇱 Poland | |
| 3 | London | 🇬🇧 United Kingdom | |
| 4 | Liverpool | 🇬🇧 United Kingdom | |
| 5 | Berlin | 🇩🇪 Germany | |
| 6 | Nizhny Novgorod | 🇷🇺 Russia | |
| 7 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 8 | Hamburg | 🇩🇪 Germany | |
| 9 | Almaty | 🇰🇿 Kazakhstan | |
| 10 | Kyiv | 🇺🇦 Ukraine |
Possible
About 20% of wildlife watchers report a Common Brimstone sighting in Sierra de Guadarrama National Park on a given day, based on 153 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 17th most-seen of the 597 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.
June and July
In those months about 30% of wildlife watchers report a Common Brimstone in Sierra de Guadarrama National Park on a given day, against under 5% in October to December, the lowest months. Those are among Sierra de Guadarrama National Park's driest months, with about 45 mm of rain a month against 110 mm in November.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Common Brimstone sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
9th of 19
Of the 19 parks where we can rate Common Brimstone sightings, Sierra de Guadarrama National Park ranks 9th at about 20%. The best odds are in Biebrza National Park (Poland, about 40%), Triglav National Park (Slovenia, about 30%) and Bavarian Forest National Park (Germany, about 30%).
GBIF citizen-science records
It is estimated from how often the Common Brimstone is recorded against all the insects logged in Sierra de Guadarrama National Park (153 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.
