The slow worm-Anguis fragilis

Slow-worms belong to the order Squamata and the Family Anguidae and placed in the genus Anguis. It is probably our commonest reptile. In days gone by , this legless lizard was referred to as the blindworm, and because there was no external evidence of limbs it was often classed with the snakes. Anatomical examination of its tructure was sufficient to do away with this notion and it was rightfully placed with the lizards. 

  Blindworm ? In his book The Young Naturalist {1909} W Percival Westell states: " It is most certainly not blind; it possesses eyelids and these being closed has doubtless resulted in the stupid name of "blind" being accorded to it. Dr Leighton has given us an excellent table of differences between lizards and snakes, it is very important  to emphasis here the distinctions that exist between these two types of reptiles----

LIZARDS                                                               SNAKES

Limbs present or rudiments                                Limbs absent

Eye lids present                                               Eye lids absent

Belly scales in several rows                              Belly scales in one row

Jaws firmly united                                            Jaws widely distensible

Teeth conical {as a rule}                                   Teeth recurved.

Tongue notched                                               Tongue deeply bifid   

Non-poisonous                                               One British species venemous.

Sternum present                                             Sternum  absent

Urinary bladder present                                   Urinary bladder absent


"The rudimentary limbs in this creature are interesting and cause it to be placed in a seperate family Anguidae, and although it would be incorrect to write of the slow-worm other than as a snake like lizard, it does serve to show some sort of connecting link between lizards and snakes"



Photograph courtesy of Marek CC BY-SA 3.0 LicenseAnguidae.jpgesy of Marek_bydg { creative commons attribution}


Description of the Slow worm, Anguis fragilis.

This native reptile may vary in colouration; the male can be uniformly greyish-brown or bronze on back and sides with a paler belly; some males have blue spotting on upper side. or the belly may be mottled black or dark grey, they also have proportionally larger heads. They measure 40-45 cm long. {14-16 inches} in length.

Females are reddish-brown with a dark vertebral stripe, may have dark flecked striped flanks and black belly.

Slow worm lifestyle and breeding.

When the weather is dull the slow-worm will conceal itself under stones and vegetation, but when the sun is out this cold blooded reptile will bathe its body in the suns warmth. In common with other lizards, the slow-worm is capable of loosing parts of its tail if necessity demands it! this capability helps the creature to evade capture from predators. This is particularly true should the slow-worm be attacked from behind. the predator will be left with a small portion of its tail, while the slow-worm escapes. It will regrow another piece to compensate for the loss, but this is seldom as long as the original part. Thus the slow-worm may well save its life by loosing this appendage. 

The movement of the slow-worm as it makes its way through the herbage is smooth and done at an easy pace, however, at times it can move with a surprising speed.

The diet of the slow-worm should be noted by the gardener for it includes a great amount of slugs and snails. Being a nocturnal creature this fact is not always appreciated. it is a sad fact that these most useful of creatures are often killed for having the unfortunate {for them} appearance of a snake. When many people think of snakes they think of being bitten and/or poisoned, hence the slow-worm suffers. Education and  the fact that they are now legally protected under the Wildlife and Countryside Act 1981, has led to a decrease in this act of persecution.

Photograph courtesy of Alex Zelenko CC BY-SA 3.0 License.

 Anguis fragilis-1.jpg


Hibernation occurs from Mid October until Late February-early March. They often hibernate communally in disused burrows, crevices under tree roots, rocks, walls or under loose leaves or stones. when they emerge from hibernation the creature may be encountered basking in the early morning and evening sun. This helps them to get conditioned for the breeding season.

The slow worm mates in spring, usually in May. The gestation period is 4-5 months and the young are borne in late summer. The slow-worm is ovi-viparous { the young being borne in an egg membrane that breaks soon after the birth}. New born slow-worms are around 65-90mm long and a brood can consist of between 6-12 with 8 thought to be about the average. broods of up to 26 have been recorded but these are exceptional. 

The young also vary in colouration from pale, golden brown, yellow, green or silver above with a dark stripe along the back.  Sides of head and belly are jet black. Males loose the dark stripe when they are old enough to breed at around three years of age.

The diet for young and for adults consists of slugs, snails, worms, insect and their larvae, small grass snakes and newborn mice and voles.

They frequent habitats such as rail way embankments, cliffs, heathland, commons, clearings in woodland, hedge banks,and old walls and ruins  so long as they are well covered with vegetation.

There are no current conservation issues concerning the slow worm, however, they are continually monitored by Conservations groups such as the Amphibian and Reptile Group. 

Photograph courtesy of Jimbojay {Creative commons attribution}

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