Colotois pennaria
In 3 days ~20% in a week ~40%
The feathered thorn (Colotois pennaria) is a moth of the family Geometridae. It was first described by Carl Linnaeus in 1761. The common name derives from the very strong feathering on the antennae of the male. Also the species name pennaria derives from the Latin suffix aria – meaning "related to or connected with" – at the end of the Latin word penna meaning "feather".
The forewings of this species are basically brown but individuals vary greatly in tone from drab light brown to much richer reddish tones. They are usually marked with two dark fascia and a small discal spot but these features can be faint or almost absent. The hindwings are lighter buffish brown. The wingspan is 46–50 mm, the males being usually larger and broader-winged than the females. Prout describes the aberrations The females tend to be rather sluggish but the males fly actively at night and are attracted to light. The species is on the wing from September to November [1].
The egg is olive-green with a ring of pale specks round the micropylar end; laid in a cluster on a twig, hibernating.The caterpillar is hairless, brown or purplish grey with ochreous spots and purplish grey... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Cévennes National Park | 🇫🇷 France | |
| 3 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 4 | Wadden Sea National Park | 🇩🇪 Germany |
With luck
About 10% of wildlife watchers report a Feathered Thorn sighting in Snowdonia National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 336th most-seen of the 387 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.
November
In that month about 40% of wildlife watchers report a Feathered Thorn in Snowdonia National Park on a given day, against under 5% in December to September, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Feathered Thorn sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.
Yes
Of the 4 parks where we can rate Feathered Thorn sightings, Snowdonia National Park has the highest daily chance: about 10%. Next come Cévennes National Park (France, under 5%) and Sierra de Guadarrama National Park (Spain, under 5%).
Same family: Geometridae
The closest relatives of the Feathered Thorn that you can see in Snowdonia National Park (family Geometridae, Geometer Moths) are Brimstone Moth (about 30%), Small Phoenix (about 20%) and Peppered Moth (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Feathered Thorn is recorded against all the insects logged in Snowdonia National Park (5 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.
