The Common Slow Worm is a species of legless lizard that can be found throughout much of Europe.
This species can even be found in places where there aren’t too many species of reptiles such as Ireland, Norway and Sweden.
They are sometimes referred to as the Blindworm or Hazelworm. However, this species isn’t actually blind.
Due to their tendency to spend most of their life burrowing, they have very small eyes much like that of a Blind Snake, hence the name.
Common Slow Worm Taxonomy
In the Animal Kingdom, Taxonomy is used as the science and practice of classifying different species and sub-species based on their biological and genetic makeup.
Family
The family that the Common Slow Worm belongs to is called Anguidae. This is a large and diverse family that is native to the Northern Hemisphere.
The types of lizards in this family include the Slowworms, Galliwasps, Glass Lizards and Alligator Lizards among a number of other species.
Some of the other species in this family include the Mexican Alligator Lizard and the Texas Alligator Lizard.
Genus
The genus that the Common Slow Worm belongs to is called Anguis. This is a small genus containing the different species of Slow Worms.
All the species in this genus are legless lizards and there are also a number of extinct fossilised species classified under this genus.
Some of the other living species in this genus include the Eastern Slow Worm, the Greek Slow Worm and the Italian Slow Worm.
Species
The scientific name for this species is Anguis fragilis and there are currently no recognised sub-species.
The species was first described in 1758 by a Swedish taxonomist named Carl Linnaeus.
Linnaeus is credited for formalising binomial nomenclature which is the modern system of naming organisms.
He has described a large number of reptiles including the Yellow Footed Tortoise, the Green Ameiva, the Eastern Copperhead, the Mediterranean House Gecko, the Northern Water Snake and the Banded Water Snake.
He also described the Ringneck Snake, the Blunthead Three Snake, the Rainbow Lizard, the Greek Tortoise, the Surinam Horned Frog, the Desert Horned Viper and the Nile Monitor.
Common Slow Worm Description
The Common Slow Worm is a legless lizard that possesses a sleek and elongated body. It typically measures between 120-200mm in snout-vent length (SVL).
The Slow Worm usually has a greyish brown or copper coloration. Juveniles can have a pale gold or silver appearance with darker colored sides.
Sexual dimorphism is apparent in this species. The female Slow Worm displays dark stripes along the back and sides of their bodies, whereas males lack these stripes.
In some cases, a small percentage of males in the eastern part of their range may exhibit distinctive blue spots on their dorsal surface.
Natural Habitat and Distribution
The Common Slow Worm can be found throughout much of mainland Europe as well as the UK and Ireland.
In mainland Europe, their range extends from the Northern parts of Portugal and Spain across countries such as France, Italy, Croatia and as far East as Bulgaria.
In the Northern parts of their range they can be found in Southern Sweden and Norway as well as Denmark, Poland, Lithuania and Latvia.
They can also be found in many of the countries further inland including Germany, Belgium, Austria, Switzerland, Czech Republic and Slovakia.
The Common Slow Worm is a semi-fossorial species, meaning it spends a significant portion of its time underground.
It thrives in environments that are damp and cool, with preferred habitats including open woodland, grassland, and heath.
Due to its inclination to avoid open areas, the Slow Worm frequently seeks refuge under stones or other surface debris.
During the winter months, it typically takes shelter in underground burrows making it challenging to observe them in their natural habitat, despite their tendency to inhabit areas near human settlements.
Common Slow Worm Behaviour
The Common Slow Worm is known to spend the majority of the year hidden in subterranean burrows, which makes it challenging to observe their behaviour.
In the United Kingdom, they typically remain underground from October to March, during the colder months.
They emerge in April for the breeding season but may retreat underground again during the hottest part of the summer.
While this lizard usually isn’t considered territorial, during the breeding season males can often become more aggressive towards each other.
Bite scars from interactions with male conspecifics have been observed on slow worms of both sexes in wild populations.
During mild summer days, they can be found near the surface, often seeking shelter beneath sun-warmed rocks.
Gravid females, in particular, seem to require a higher body temperature and may occasionally come out to bask in direct sunlight.
The Common Slow Worm is a carnivorous species with its diet predominantly consisting of slugs and earthworms.
They are an ovoviviparous species, meaning that the eggs develop and hatch inside the female and the young are born live.
The timing of the breeding season and gestation period of the Common Slow Worm can vary across different regions.
In the United Kingdom, the breeding season typically takes place around April or May, and the young are born in August or September.
In places where the climate is warmer, such as the Iberian Peninsula, mating can occur earlier.
