Operophtera brumata
In 3 days ~10% in a week ~20%
The winter moth (Operophtera brumata) is a moth of the family Geometridae. It is an abundant species in Europe and the Near East and a famous study organism for evaluating insect population dynamics. It is one of very few lepidopterans of temperate regions in which adults are active in late autumn and early winter. The females of this species are virtually wingless and cannot fly, but the males are fully winged and fly strongly. After the initial frosts of late fall, the females emerge from their pupae, walk to and up trees and emit pheromones in the evening to attract males. After fertilization, they ascend to lay, on average, around 100 eggs each. Typically, the larger the female moth is, the more eggs she lays.
The winter moth is considered an invasive species in North America. Nova Scotia, Canada, experienced the first confirmed infestations in the 1930s. It was later accidentally introduced to Oregon in the 1950s and the Vancouver area of British Columbia around 1970. Defoliation by the moth was first noted in eastern states of the United States in the late 1990s, and is now well established in Massachusetts, Rhode Island, New Hampshire and Maine. The winter moth is confirmed present in British Columbia, Washington and Oregon. In Massachusetts, the moths have attracted the attention of several media outlets due to the severity of the infestation. Efforts at biological control are underway. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 2 | Cévennes National Park | 🇫🇷 France | |
| 3 | Pyrénées National Park | 🇫🇷 France | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany |
Rare
Under 5% of wildlife watchers report a Winter Moth sighting in Wadden Sea National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 699th most-seen of the 818 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
November
In that month about 20% of wildlife watchers report a Winter Moth in Wadden Sea National Park on a given day, against under 5% in December to October, the lowest months. That is one of Wadden Sea National Park's wettest months, with about 140 mm of rain against 45 mm in April.
Between 4 and 7 pm
Across all the parks we cover, that three-hour window holds the most Winter Moth sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.
4th of 4
Of the 4 parks where we can rate Winter Moth sightings, Wadden Sea National Park ranks 4th at under 5%. The best odds are in Bavarian Forest National Park (Germany, about 10%), Cévennes National Park (France, under 5%) and Pyrénées National Park (France, under 5%).
Same family: Geometridae
The closest relatives of the Winter Moth that you can see in Wadden Sea National Park (family Geometridae, Geometer Moths) are Riband Wave (about 10%), Yellow Shell Moth (about 10%) and Small Engrailed (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Winter Moth is recorded against all the insects logged in Wadden Sea National Park (6 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.
