Urban Slow-worms in Worcester City

By Alan Shepherd

The Slow-worm is a species in national decline despite the impression that its wide distribution may give and Herpetofauna workers have long been aware of the increasing importance of urban sites for this enigmatic reptile. It seems particularly capable of adapting to life on disused allotments or derelict industrial sites and frequently occurs in gardens without the owner being aware of its presence unless it is disturbed when lying up under the cover of the compost heap.

In 1997, the Trust's Worcestershire Wildlife Consultancy was contracted to undertake Britain's first ever survey of an urban area that specifically targeted the slow-worm. This was on behalf of Worcester City Council's Project Greenspace and it has served to highlight just how important the "Faithful City" is for this shy and engaging reptile.

Using a recognised methodology of putting down refugia on the 27 selected sites and making two visits per site (in suitable weather conditions) at fortnightly intervals some basic data was obtained.It is a sad fact that after 25 million years in its current form relatively little is known about the slow-worm - for instance what does it do most of the time? Using tin sheets to attract thigothermic reptiles makes counting easier and on all the survey sites highest number counts were taken. The opportunity to acquire some data on the population dynamics was taken by sexing and ageing specimens whenever possible: slow-worms can be recognised by their individual parietal markings in the same way as adders but within the limits of this project this would have been impossible.

The results of the survey confirm what was always believed - that Worcester does indeed have a large and widely distributed slow-worm population. Part of the survey involved an appeal for public sightings via local radio and press and this yielded 137 replies,all duly passed on to the BRC.

It is virtually impossible to get a Herp worker to put a figure on the possible size of a slow-worm population but Nick Dane Smith in his unpublished PhD suggests a potential of 1000 per hectare in suitable habitat. It is a fact that a translocation from one of the best sites in Worcester yielded 387 captures from 1.25 ha. Anne Riddell in conversation said that she felt that the creatures spend more time buried in the soil than we think; what is certain is that the weather conditions usually thought of as optimum for reptiles do not apply in the case of the slow-worm. In hot weather it will bury itself in the soil, in cooler conditions it will lie under debris, but in damp conditions when its favoured prey, the slug, emerges so does 'Old No-Legs', often hunting at dusk.

It seems that the local press trumpeting Worcester as the Slow-worm Capital of Britain is not so far away from fact as it may have seemed. More excitingly, from a conservation angle, at a meeting on one of the prime allotment sites (with potentially the largest single urban slow-worm population in Britain until somebody finds a better candidate) my suggestion that improvement works to access paths could be combined with purpose-designed hibernacula was greeted by the question as to whether I felt that a sanctuary area would be of any use. So we now have the first ever City Council designated slow-worm sanctuary in the world complete with hibernating and hiding areas!


Riddell, A (ed) (1997) The Slow-worm. Kent Reptile & Amphibian Group.

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