The slow worm is a European lizard within the anguinae taxon which contains three genera. These are anguis, pseudopus and ophisaurus. The latter genus contains the glass lizards common to the United States. All are part of the much larger anguidae family, which occurs widely in Europe and Central America, and are also present in the southern half of United States, southern Brazil, plus parts of southern and south-west Asia.
Anguis fragilis is found in the British Isles and across most of Europe including southern Scandinavia. The nominate species, anguis fragilis fragilis, occurs in western Europe while anguis fragilis colchicus is the eastern European species. Anguis cephallonicus is the other anguis species, which occurs in southern Greece and on the islands of Zakynthos and Cephalonia.
Slow Worm Characteristics
Sometimes known as the blind worm although it is actually quite well-sighted, the slow worm is not a snake but a legless lizard. Tongues of slow worms are different to snakes, being wider and thicker than snake tongues and also unforked. The slow worm does not flick its tongue like a snake, but extends and withdraws it much more slowly. The slow worm also has eyelids and can blink, and slow worm scales are arranged differently on its underside than those of a snake. A slow-worm's scales are also smaller than those of most adult European snakes, giving slow worms a smooth, sleek appearance. The slow worm is well-armored by scales covering its body that have underlying plates of bone known as osteoderms beneath them.
Slow worm colors often match the color of their usual surroundings, so that they are brown or grey, with their undersides silver grey or black. Females have a fine longitudinal dark stripe running the length of their body. Sometimes they also have brown spots positioned in rows running parallel to the main stripe. Adult males in some areas develop blue spots on their flanks. Males tend to have a slightly more pronounced head and neck than females. Young slow worms are not as dull in color as adults and are often a golden brown with a dark brown, occasionally black, longitudinal stripe. Slow worm hatchlings are often almost yellow in color, with dark undersides.
Slow worms are normally around 16 to 20 inches long if they have a complete tail, which makes up around, or just over, half the length of their body. They can shed their tails readily if attacked or touched. This is a natural defense mechanism known as autotomy which confuses predators and buys time to escape. Autotomy is something that the slow worm has in common with salamanders and some lizards. Although a tail that has been shed in this way will grow back in time, a regenerated tail is not as natural-looking as the original, often shorter and sometimes stubbier, or occasionally much slimmer than the rest of the slow worm's body in appearance.
Slow worms also shed their skin. This can happen a few times during a summer if food is plentiful so that the slow worm can comfortably put on weight before winter. Slow worms are normally active from spring to the late fall and mate during the late spring. When mating, a male slow worm grabs the female's head in his mouth while manoeuvring his body into position. Females will retain fertilized embryos over the winter if mating is late or the climate is too cool.
Normally female slow worms give birth during late August or early September. From eight to around twenty-five young are born in a thinly-covered neonate or pellicle which the live slow worm emerges from almost immediately. The newborn slow worm is around three inches long and is independent of the female parent from birth. Slow worms are believed to live for around 30 years in the wild, but are known to have survived for over 50 years in captivity.
Slow Worm Habitat
Slow worms prefer a generally moist habitat, while food availability determines the exact location. They can be found in fairly dense populations where the habitat is suitable and are known to share suitable basking sites and winter hibernation dens. They do show some flexibility in environment and can be found at heights of more than 6000 feet above sea level in parts of Europe.
Slow worms tend in many respects to be more secretive than snakes. Slow worms tend to have to be sought out and are often part-hidden in undergrowth when they are active and even when basking. Their normal habitat includes scrub and habitats with dense ground cover, including woodland, hedges, grass verges and embankments and quiet gardens. As with grass snakes, undisturbed compost heaps can also be inhabited if the surroundings are damp enough. Slow worms are diurnal but are usually at their most active at dusk. They eat snails, slugs, worms, spiders and small vertebrates including young rodents. They are known particularly for eating the netted slug, derocera reticulatum, which endears them to some gardeners.
They do not like direct sunlight when the weather is very warm though expectant females occasionally will bask in it. Slow worms tend to bury themselves deeper in the undergrowth or underground when the climate is warm. The lizard does not really dig for itself but lives in disused burrows and on or near the ground surface, it travels through material previously loosened by other animals.
A well-known behavior of the slow worm is to bask under rocks whose top surface is exposed to the sun, so that the slow worm gains some heat. They can also be found lying under undisturbed rubbish if the covering is large and flat, such as discarded cardboard or corrugated metal and their like. A slow worm sometimes exhibits a slow lurching kind of movement, but will normally move quickly through loose soil, leaf litter and undergrowth.
Slow worms are not normally kept by hobbyists. They can be kept in a terrarium equipped with a damp substrate, flat stones and a shallow dish of water. Provision has to be made to allow them to hibernate in winter, while around 80F in summer is suitable for basking but cooler retreats will also be required. They are better served by a large area and ready food source, and it is more humane to try and provide a suitable wildlife garden habitat for these intriguing reptiles.
Ian Dutton - My writing is part of my lifelong fascination with all spects of plants and animals. My homepage at Naturepieces explains more. My ...
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