Anguis fragilis
Silhouette: Steven Traver · PhyloPic
In 3 days ~70% in a week ~90%
The common slow worm (Anguis fragilis) is a non-venomous species of legless lizard native to Europe. It is also called a deaf adder, blindworm, or regionally, a long-cripple, steelworm, and hazelworm. Despite its name, the common slow worm is neither a worm nor a snake.
Common slow worms are semifossorial (burrowing) lizards that spend much of their time hiding underneath objects. The skin of slow worms is smooth, with scales that do not overlap. The "blind" in blindworm refers to the lizard's small eyes, similar to a blindsnake (although the slow worm's eyes are functional). The common slow worm, i.e. the species Anguis fragilis, is often called simply "slow worm", though all species of the species complex comprising the genus Anguis are also called "slow worms".
The name "slow worm" is only contaminated by the word "slow". In Middle English, it was written "slowurm", from Old English "slāwyrm", where slā- means 'earthworm' or 'slow worm' and wyrm means "serpent, reptile". It is related to the Norwegian slo or Swedish ormslå, of same meaning.
However, recent... Wikipedia →
Recording0:53
Poland · 2026
© Liudmyla · iNaturalist · CC BY-NC 4.0
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Austria · 2025
© kaulquappe · iNaturalist · CC BY-NC 4.0
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Spain · 2026
© NPound · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Triglav National Park | 🇸🇮 Slovenia | |
| 3 | Plitvice Lakes National Park | 🇭🇷 Croatia | |
| 4 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 5 | Cévennes National Park | 🇫🇷 France | |
| 6 | Picos de Europa National Park | 🇪🇸 Spain | |
| 7 | Pyrénées National Park | 🇫🇷 France | |
| 8 | Biebrza National Park | 🇵🇱 Poland | |
| 9 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 10 | Aigüestortes National Park | 🇪🇸 Spain | |
| 11 | Fertő-Hanság National Park | 🇭🇺 Hungary | |
| 12 | Hohe Tauern National Park | 🇦🇹 Austria | |
| 13 | Ecrins National Park | 🇫🇷 France | |
| 14 | Wadden Sea National Park | 🇩🇪 Germany |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | AQUA Akvarium & Dyrepark | 🇩🇰 Denmark |
No species of the same family or order lives in Picos de Europa National Park, so these are its closest relatives here: other reptiles.
Possible
About 30% of wildlife watchers report a Slow Worm sighting in Picos de Europa National Park on a given day, based on 21 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 4th most-seen of the 10 reptiles we can rate there. Over three days the chance rises to about 70%, and over a week to about 90%, if each day is a fresh chance.
May and October
In those months about 50% of wildlife watchers report a Slow Worm in Picos de Europa National Park on a given day, against under 5% in March and September, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Slow Worm sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
6th of 14
Of the 14 parks where we can rate Slow Worm sightings, Picos de Europa National Park ranks 6th at about 30%. The best odds are in Snowdonia National Park (United Kingdom, about 60%), Triglav National Park (Slovenia, about 50%) and Plitvice Lakes National Park (Croatia, about 50%). All parks ranked.
GBIF citizen-science records
It is estimated from how often the Slow Worm is recorded against all the reptiles logged in Picos de Europa National Park (21 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.
