Colotois pennaria
In 3 days ~10% in a week ~20%
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 |
Rare
Under 5% of wildlife watchers report a Feathered Thorn sighting in Milan on a given day, based on 5 verified sightings from GBIF citizen-science data. It is the 315th most-seen of the 351 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 Feathered Thorn in Milan on a given day, against under 5% in December to September, the lowest months. That is one of Milan's wettest months, with about 140 mm of rain against 45 mm in January.
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.
18th of 21
Of the 21 cities where we can rate Feathered Thorn sightings, Milan ranks 18th at under 5%. The best odds are in Kharkiv (Ukraine, about 20%), Liverpool (United Kingdom, about 10%) and Vienna (Austria, about 10%).
Same family: Geometridae
The closest relatives of the Feathered Thorn that you can see in Milan (family Geometridae, Geometer Moths) are Vestal (about 10%), Willow Beauty (about 10%) and Common Heath (about 10%), 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 Milan (5 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.
